Google

This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project

to make the world's books discoverable online.

It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject

to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books

are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover.

Marks, notations and other maiginalia present in the original volume will appear in this file - a reminder of this book's long journey from the

publisher to a library and finally to you.

Usage guidelines

Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the
public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing tliis resource, we liave taken steps to
prevent abuse by commercial parties, including placing technical restrictions on automated querying.
We also ask that you:

+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for
personal, non-commercial purposes.

+ Refrain fivm automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine
translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the
use of public domain materials for these purposes and may be able to help.

+ Maintain attributionTht GoogXt "watermark" you see on each file is essential for in forming people about this project and helping them find
additional materials through Google Book Search. Please do not remove it.

+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just
because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other
countries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of
any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner
anywhere in the world. Copyright infringement liabili^ can be quite severe.

About Google Book Search

Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers
discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web

at |http: //books .google .com/I

D,g,t,.?<i I,, Google

D,g,t,.?<i I,, Google

D,g,t,.?<i I,, Google

I,, Google

r:,9,N..<ib, Google

r:,9,N..<ib, Google

SMOKELESS POWDER,
NITRO-CELLULOSE,

AND

THEORY OF THE CELLULOSE
MOLECULE

JOHN B. BERNADOU,

a. United Stalls Navy

FISSr EDITION
FIRST THOUSAND

NEW YORK

JOHN WILEY & SONS

LoHDoKi CHAPMAN & HALL, Limitbo

1901

r:,9,N..<ib, Google

<'V ■

JOHN B. BERNADOU

n,<i-^f^:>yG00glc

iV-

PREFACE

For purposes of comparative study, the writer has
brought together in the present volume a scries of
papers, by various investigators, upon the composition
of cellulose and the properties of explosives prepared
therefrom. He has supplemented these with an ac-
count of experiments made by himself; and from the
whole has drawn certain conclusions as to the possible
ultimate chemical composition of cellulose and the
nitro-celluloses.

While the general development of war-material
from the mechanical and metallurgical standpoints —
the production of ordnance and armor — is so largely
identified with progress in the useful arts in the
United States, yet, until very recently, but little has
been accomplished in our country in the way of im-
provement in explosives. Within the last few years,
however, a particular form of smokeless powder has
largely supplanted the old black and brown powders
for military uses; and the last decade of the past
century has witnessed the virtual abandonment of
a propellant that has held its place in war, with

92333 c,,,„.,Google

comparatively little modification, for four hundred
years.

This new smokeless powder, which is adapted for
use in arms of all calibres, is prepared from a particu-
lar type of colloid nitro-cellulose. Such an extension
of the employment of this latter body from its original
use for detonating purposes, to its new use as a pro-
gressive explosive, has attracted general attention, and
led to a more careful and extended study of the nitro-
celluloses in general. It is with the view of further
extending such study and of possibly preparing the
way for the introduction of future improvements in
progressive explosives that this book has been pre-
pared.

Before presenting it, the author wishes to. express
his thanks to certain eminent scientists for the privi-
lege that they have courteously afforded him of
making his own translations of certain portions of their
works upon explosives: to Professor D. Mendel^ef,
of Russia, for his paper entitled " Pyroc olio d ion
Smokeless Powders"; to M. Vieille, of the French
Service des Poudres et Salpetres, for his article upon
the nitration of cotton ; and to M. Bruley, of the same
service, for a similar paper. Thanks are due also to
Messrs. Longmans, Green & Co. for the privilege
kindly extended of making certain extracts from
Messrs. Cross and Bevan's valuable work, "Cellulose,"
published by them.

Finally, the author wishes to express his indebted-
ness to Dr. Alfred I. Cohn, of New York, for the care
he has bestowed upon the reading of the proof of

D,g,t,.?<i I,, Google

this book at a time when the writer's absence from
the United States on active service afloat prevented
his giving the matter the personal care and attention
it otherwise would have had; and for his prepara-
tion of a comprehensive index.

U. S. S. " Dixie," April 24, 1901.

D,g,t,.?<i I,, Google

r:,9,N..<ib, Google

TABLE OF CONTENTS

CHAPTER I

Ori^n 1

Nomenclature , 4

DeAniticma 6

CHAPTER II
Eaklieb Views ab to NiTso-CELLrLOSE Couposition and

COKBTITXJTIOH 8

CHAPTER ni

ThA Conception of PEOOKEasioN in Relation to Compo-
BiTiON AND Constitution 21

CHAPTER IV

SoLimoNS or NiTEO-cELLuix)aE. Theobt of the Cellu-
Loaa MoLEcuLB 38

APPENDIX I

Researches Upon the Niteation of Cotton. By M.

VlEILLB 81

I. First Method of Nitration 81

II. Second Method of Nitration 87

in. Higher Limit of Degree of Nitration !)1

IV. Cdlulose Incompletely Nitrated. 92

V, ResnmS and Conclueions 04

vii

D,g,t,.?<i I,, Google

TABLE OF CONTENTS

APPENinX II

PVBOCOIXOmON SUOKELEBB PoWDEBS. By PBOFESBOB D.

Mendbleef 97

APPENDIX III

Thb Nitratioti of Cotton. Br M. Bbulet 127

I. Method of Nitrafion and Mode of Bepreseuting BesulU. . 130

II. Eesulta Obtained by M. Vieille 131

III. Ebtperimenta in Nitration (First Series) 134

IV. Experiments in Nitration (Second Series} 140

V. Experiments in Nitration (Third Series) 141

VI. Various Experiments. 144

Vn. Resume and ConclueioDS. 152

APPENDIX IV

D,g,t,.?<i I,, Google

SMOKELESS POWDER

CHAPTER I
ORIGIN

The discovery that cellulose, by treatment with
nitric acid, is converted into a highly inflammable or
explosive body was made during the Brst half of the
nineteenth century. The action of nitric acid on
starch was investigated to some extent in 1833 by
Braconnot, who found that a very rapidly burning
material was produced, and which he named xyloidine.
Pelouze further investigated this substance in 1838,
and also studied similar bodies prepared from paper,
linen, etc., which he held to be identical with the one
from starch.

In 1846 SchSnbein discovered that cellulose in the
form of cotton, when immersed in nitric acid, freed
from the acid excess, and dried, was converted into a
highly explosive compound. This latter substance,
subsequently known as gun-cotton, constitutes the
base of modern smokeless powders.*

• The name " gun-eotlon,"a9 originally employed, was generic
for all Tarieiies of Ihe mote highly explosive nitro-celiuloses pre-
pared from cotton.

D,g,t,.?<i I,, Google

a sMoxrsLSss powder

On its first appearance gun-cotton was hailed by
ordnance experts as a smokeless substitute for gun-
powder, and extended series of experiments were con-
ducted to prove its adaptability to the requirements of
war. The combined efforts of chemist, powder-maker,
and artillerist failed, however, to secure such a control
of its combustion as would enable it to be safely em-
ployed, in chaises of a given weight, to develop a uni-
form bore-pressure with standard ftrojectiles in guns of
a given calibre. After the occurrence of a number of
detonations, unlocked for and more or less disastrous,
its use was abandoned. Nevertheless, the study of
the composition, properties, and methods of production
of gun-cotton and kindred bodies continued to be sys-
tematically prosecuted, the theory of nitro-substitution
was evolved, and the knowledge of the applicability of
the new materials to military requirements extended.
But more than forty years were to elapse from the
time of the first experiments before a thoroughly re-
liable smokeless powder, free from all tendency to
detonation, producing minimum erosion, of good
keeping qualities, and of maximum propulsive effect,
was to be obtained.

To trace the various steps of progress in the deter-
mination of the properties of gun-cotton is exceed-
ingly dif^cult. It is primarily difficult for the reason
that the base-material under investigation possesses
an organic structure; and because the resultant nitrated
product varies in chemical composition according to
strength and temperature of the acids employed in
its preparation, their water content, duration of re-

D,g,t,.?<i I,, Google

ORIGW 3

action, and temperature at which the reaction is con-
ducted. It is difficult secondarily for the reason that
the ultimate product of nitration is either resolvable,
by treatment with certain solvents, into different sub-
components, or else is capable of direct preparation in
a form soluble in one or another solvent; and because
certain industries, sciences, and professions — the man-
ufacture of explosives, of fabrics, photography, sur-
gery — have required the development of special forms
of material and demanded special lines of research.

The existence to-day of a very large number of
unclassified names to denote the different varieties of
nttro-cellulose, serves as an illustration of the necessa-
rily involved and complex nature of such investigations
as have been made for the purpose of determining its
composition, and of the incompleteness of these inves-
tigations. The confusion in nomenclature that has
arisen is attributable to the fact that the formula for
cellulose, and therefore for the cellulose nitrates, not
being established, investigators in different countries
started in independently to determine simultaneously
both the properties of these compounds and their
chemical constitutions. Matters became further in-
volved through the efforts to translate the accounts of
the work of one investigator into the language of
another.

With the view of avoiding confusion in the future it
may be well to anticipate somewhat here, to indicate
the origin of the various names applied to forms of
nitro-cellulose, to define and classify them, and to
indicate such of them as will be employed hereafter in

D,g,t,.?<l I,, Google

4 SMOKELESS POWDER

the body of the present work ot denote those distinct
varieties that possess significance from the standpoint
of explosive effect.

NOMENCLATURE

Names may be divided into classes, according to
origin, as follows:

I. — Those devised by discoverers to denote new
chemical compounds. Thus, xyloidin, from Hvkoi,
wood; pyroxylin, from nvp, fire, and £v\oi, wood.

2. — Those implying uses to which special forms of
the material are applied, as gun-cotton, collodion-cot-
ton.

3. -i— Those originating in references to the theory
of nitro-3ubstitution ; thus, nitro-cellulose, mono-, di-,
tri-, tetra-, penta-, etc.. nitro-cellulose.

4, — Names based upon the physical characteristics
of the material, as "soluble nitro-cellulose," "insol-
uble nitro-cellulose," " friable cottons" (Vieille).

5. — Names obviously incorrect as to application and
meaning, as " soluble cotton " for soluble nitro-cellu-
lose; " insoluble cotton " for insoluble nitro-cellulose.

6. — Generic names for groups of varieties between
which differences in chemical composition were recog-
nized as existing; thus, nitro-celluloses as opposed to
nitro-hydrocelluloses.

7, — Names referring to chemical composition as
modified by extent and characterof nitro-substitution,
as "soluble nitro-cellulose of high nitration," of "low
nitration."

D,g,t,.?<i I,, Google

DEFINITIONS

Cellulose. — The cell-wall or envelope of plant-tissues,
to which the name cellulose has been applied as to a
chemical individual. Unless the contrary is stated,
the term cellulose, as employed in the present work,
refers to pure cotton, unbleached and unspun, freed by
mechanical treatment (ginning, picking, boiling, etc.)
from wood, dirt, greases, resins, and foreign matter in
general; either in the natural state, or as waste product
from industrial processes.

Nitration. — The displacement of a number of atoms
of replaceable hydrogen in cellulose, and the substitu-
tion therefor of the univalent radicle nitryl (NO,).
The term " nitration " is also employed to indicate the
percentage of nitrogen in a given nitro-cellulose.

Nitro-cellulose . — Products resulting from the treat-
ment of cellulose with strong nitric acid under the
condition that they retain the cellular structure of the
original cotton,

Nitro-cellulose of high nitration. — Those forms of
nitro-cellulose in which a relatively large number of
the replaceable hydrogen atoms are replaced by nitryl,

Nitro-cellulose of mean nitration. — Those forms of
nitro-cellulose in which a mean number of the replace-
able hydrogen atoms are replaced by nitryl.

Nitro-cellulose of low nitratio?i. — Those forms of
nitro-cellulose in which a relatively small number of
replaceable hydrogen atoms are replaced by nitryl.

Insoluble nitro-cellulose. — Those forms of nitro-cel-
lulose of high nitration insoluble at ordinary atmos-

D,g,t,.?<i I,, Google

6 SMOKELESS POWDER

pheric temperatures in a mixture of two parts by
weight of ethyl ether and one part by weight of ethyl
alcohol.

Soluble nitro-cellulose. — Those forms of nitro-cellu-
losc of low or mean nitration soluble at ordinary at-
mospheric temperature in a mixture of two parts by
weight of ethyl ether and one part by weight of ethyl
alcohol.

Hydrocellulose. — The product obtained by exposing
cotton to the action of hydrochloric-acid fumes; or by
immersing it in hydrochloric, dilute sulphuric, or very
dilute nitric acid ; a white pulverulent mass which,
under the microscope, is seen to consist of fragments of
the original fibre of modified cellular form.

NitTo-hydrocellulose . — Products resulting from the
treatment of hydrocellulose with strong nitric acid
under the condition that the resultant product retains
the cellular structure originally possessed by the hy
drocetlulose.

Nitro-kydrocellulose of high nitration. — Those forms
of nitro-hydrocellulose in which a relatively large
number of the replaceable hydrogen atoms are replaced
by nitryl.

Nitro-hydrocellulose of mean nitration. — Those
fonns of nitro-hydrocellulose in which a mean number
of the replaceable hydrogen atoms are replaced by
nitryl.

Nitro-kydrocellulose of low nitration. — Those forms
of nitro-hydrocellulose in which a relatively small
number of replaceable hydrogen atoms are replaced by
nitryl.

r:,9,N..<ib,G00gIe

Insoluble nitro-hydrocelluhse. — Those forms of nitro-
hydrocellulose of high nitration insoluble at ordinary
atmospheric temperatures in a mixture of two parts
by weight of ethyl ether and one part by weight of
ethyl alcohol.

Soluble nitro-kydrocellulose. — Those forms of nitro-
hydrocellulose of low or mean nitration soluble at
ordinary atmospheric temperatures in a mixture of
two parts by weight of ethyl ether and one part by
weight of ethyl alcohol.

Gun-cotton. — ^The military name for those forms of
highly explosive nitro-celluloses employed in war, and
which are generally mixtures of a large quantity of in-
soluble with a small quantity of soluble nitro- cellulose
and a very small quantity of unnitrated cotton.

Pyrocellutose. — Soluble nitro-cellulose of high uni-
form nitration, possessing a sufficient content of oxy-
gen to convert its carbon into carbonic oxide and its
hydrogen into aqueous vapor.

These terms, as defined above, will be employed so
far as possible in the body of this treatise. The follow-
ing list of synonyms is supplied for reference :

Nune Sjaooi'm

Nitrocellulose, Pyroxyline or pyrox;liD.

Insoluble nitro-cellulose, Insoluble gun-cotlon ; insolu-

ble cotton.
Soluble nitro-cellulose, Soluble gun-cotlon; •oluble

cottoD \ collodion-cotton; col*
iDdion-pyroxflia.

r:,9,N..<ib, Google

CHAPTER II

EARLIER VIEWS AS TO NITRO-CELLULOSE COM-
POSITION AND CONSTITUTION

Existing knowledge of the composition and consti-
tution of nitro-cellulose still remains in a state of great
confusion. A number of papers, scattered through-
out the literature of experimental chemistry, and
which throw valuable light upon the subject, have been
published by independent investigators, while from
time to time more elaborate articles summarizing the
results of early workers have appeared. At least one
excellent treatise upon cellulose has been published, *
but it devotes only a few pages to the consideration
of the nitro-celluloses. The reason for the existing
confusion is that as yet no definite chemical structure
has been determined for nitro-celluloses ; they are re-
garded as nitro-substitution compounds, as ethers, or
else their composition is considered as still doubtful.

If, however, the various original experimental re-
sults and the conclusions that have been drawn there-
from be examined in sequence, it will be observed that
there does exist a tendency to account for the compo-
sition of these bodies on a definite hypothesis. There-

•" Cellulose," CiOBB and Bevan. London ; L.ongroans, Green
& Co., 1E95.

r:,9,N..<ib, Google

EARLIER VIEWS AS TO NITRO-CELLULOSE 9

fore the writer, in his endeavor to throw some light
upon ultimate cellulose- and nitro-cellulose composi-
tion, will take up (or consideration, first of all, in
natural order of succession, results obtained by a
number of students, each of whom, in his work, has
supplied material from which subsequent investigators
have drawn important conclusions.

Almost from the beginning of the study of the body
the existence of more than one form was recognized.
Domonte and Menard's discovery that pyroxylin of
low nitration was soluble in ether-alcohol, while the
more highly nitrated variety remained insoluble there-
in; furnished a positive differentiation of nitro-cellu-
loses into two groups ; B^champ showed that there
existed nitro-celluloses of different nitrations soluble
in ether-alcohol ; and the only way of explaining the
existence of such differences, in accordance with
chemical theory, was by assuming that the substances
of varying degrees of nitration obtained consisted of
mixtures of various quantities of different, definite,
chemical compounds.

The numerous attempts to explain both the mode
of formation of nitro-cellutose as well as its constitu-
tion, and to reconcile results from its analyses, are well
illustrated by the formulae selected by early investi-
gators to represent its varieties. Of these formulas,
ipumerous series exist, extending from the original
formula of Schdnbein, through the later formulated,
so-called mono-, di-, and tri nitro-cellu loses, to the
series of six nitrates of Eder. At an early date the
belief became established, based in all probability upon

D,g,t,.?<i I,, Google

lO SMOKELESS POWDER

analogies furnished by the nitro-glycerins and nitro-
benzoh, that nitro-celluloses were mixtures of nitro-
substitution products, which, assumingthe composition
of cellulose as C,Hi,0,, were formulated as the tri-, di-,
and mononitrates, with compositions C,H,0,(NO,)„
C,H,0.(NO,)„ and C.H.O.(NO,), respectively. Of
these, trinitro-cellulose was considered as identical
with the insoluble variety of high nitration, and di-
nitro-cellulosc with that soluble in ether-alcohol; the
existence of the mononitro-cellulose was predicated.
Certain reactions due to these bodies led to a change
of views concerning their chemical structure, B^champ
found that nitro-celluloses dissolved in ether-alcohol
surrendered nitric acid upon addition of potash or
ammonia, with the resultant formation of nitro-cellu-
loses of lower nitration; he claimed for them the
composition of ethers,*

Other reactions of the nitro-celluloses tend to sup-
plement this view of their composition; e.g., ferric
chloride and potassium and ammonium sulphydrates

* An ether is one of a class of organic bodies divided into two
groups : (l) simple ethers, consisting of two basic hydrocarbon
radicles nniced by oxygen, and corresponding in constitution to
the metallic oxides, as CHiOCH,. methyl ether, or methyl oxide,
analogous lo AgOAg, silver oxide ', (z) compound ethers, consist-
ing of one or more basic or alcohol radicles and one or more acid
or hydrocarbon radicles united by oxygen, and corresponding to
the salts of the metals, as CH.COOC.H,. ethyl acetate or acetic
ether, corresponding to CHiCOONa. sodium acetate. Thus, if a
cellulose be represented as possessing a composition CiHuOt,
and be written as a tribasic alcohol, C.HiO, (OH)i, [hen, on sub-
stituting nitryl, NOg, for the replaceable hydrogen, we obtain
C.H)0,Oi(NO,)i, a compound nitric ether.

D,g,t,.?<i I,, Google

EARLIER VIEWS AS TO NITRO-CELLULOSE II

(Hadow, von Pettenkofer, cited by Guttmann) occasion
the recovery of their cellulose, while the liberated
nitric acid oxidizes the iron of the ferric chloride and
transforms the sulphydrates into nitrates.

In 1878 Dr. J, M. Eder conducted a series of in-
vestigations into the character and composition of the
nitro celluloses which has had much influence upon
subsequent formation of thought in relation to the
character and composition of these bodies; and from
the results of his labors he was led to conclude that
there existed no less than six distinct varieties of them,
three of which, the hexa-, penta-, and di-, he was able
to isolate ; two of them, the tetra- and tri-, he obtained
in admixture; the mononitro-cellulose. however, he
was unable to prepare. Doubling the coefficients of
cellulose to avoid fractional coefficients in the deriva-
tives, he formulated his series of nitrates as follows:
Table II

Name Compmition

Cellulose hexaoittate. . C,9HiiO.(NO0>

Cellulose pencaniirate CiiHiiOt(NOi)i

Cellulose tetranitrate C,,H„0.(NO,).

Cellulose trinitrate C„H„0,(NO.),

Cellulose dinitrate C,.H„0,(NO.),

Cellulose mononitrate

Dr. Eder's work constituted a purely scientific re-
search into the chemical properties of a group of
bodies. Subsequent investigations are characterized
by the partial subordination of their scientific aims to
the demands of the useful arts. These investigations
are of two kinds, and refer to the technical uses of the
soluble and insoluble varieties respectively. Those

D,g,t,.?<i I,, Google

12 SMOKELESS POWDER

upon the soluble nitro-celluloses relate, for example, to
photography, — to questions of transparency and uni-
formity of thickness of film ; those upon insoluble nitro-
celluloses, to the art of war and to the attainment of
the highest explosive effect consistent with the main-
tenance of stability. The general purpose of the
present work is the study of the physical and chemical
properties of nitro-celluloses and nitro-cellulose col-
loids, their methods of preparation, and their explosive
qualities; and to the prosecution of this study investi-
gations of the second class have, until recently,
afforded the more direct aid. Conditions of research
have, however, been recently modified. For, whereas
the explosives prepared from cotton were formerly
insoluble nitro-celluloses (gun-cottons) susceptible of
detonation as well as of combustion, and employed in
mines and torpedoes, yet in recent times the field of
research has been extended to the soluble varieties in
the effort to secure a suitable base material for the
preparation ofanon^detonating, progressively- burning,
smokeless powder.

The following account of Eder's nitrates (taken
from Cross and Bevan, " Cellulose " *) may be quoted
here:

" Hexanitrate, C„H,.0.(NO.),, gun-cotton. In
the formation of this body, nitric acid of 1. 5 sp. gr.
and sulphuric acid of 1.84 sp. gr. are mixed in vary-
ing proportions, about 3 of nitric to i of sulphuric;
sometimes this proportion is reversed, and cotton

* By permission of Loogmans, Green & Co.

D,g,t,.?<i I,, Google

EARLIER VIEWS AS TO NITRO-CELLVLOSE 13

immersed in this at a temperature not exceeding
lO" C. for 24 hours; 100 parts of cellulose yield
about 175 of cellulose nitrate. The hcxanitrate so
prepared is insoluble in alcohol, ether, or mixtures
of both, in glacial acetic acid or methyl alcohol.
Acetone dissolves it very slowly. This is the most
explosive gun-cotton. It ignites at i6o''-i7o'^ C.
According to Eder the mixtures of nitre and sul-
phuric acid do not give this nitrate. Ordinary gun-
cotton may contain as much as 12 per cent, of nitrates
soluble in ether-alcohol. The hexanitrate seems to
be the only one quite insoluble in ether-alcohol."

" Pentanitrate, C„H,.0,(NO,).. This composition
has been very commonly ascribed to gun-cotton.
It is difficult, if not impossible, to prepare it in a state
of purity by the direct action of acid on cellulose.
The best method is the one devised by Eder, making
use of the property discovered by De Vrij, that gun-
cotton (hexanitrate) dissolves in nitric acid at about
80° or 90° C, and is precipitated, as the penta-
nitrate, by concentrated sulphuric acid after cooling
to o" C. ; after mixing with a large volume of water,
and washing the precipitate with water and then with
alcohol, it is dissolved in ether-alcohol and again pre-
cipitated with water, when it is obtained pure. This
nitrate is insoluble in alcohol, but dissolves readily
in ether-alcohol, and slightly in acetic acid. Strong
potassa solution converts this nitrate into the di-
nitrate, C„H,.0.(NO.),."

"The tetra- and trinitrates (collodion -pyroxylin)
are generally formed together when cellulose is

D,g,t,.?<i I,, Google

I4 SMOKELESS POWDER

treated with a more dilute nitric acid, and at a higher
temperature, and for a much shorter time {13-20
minutes), than in the formation of the hexanitrate.
It is not possible to separate them, as they are sol-
uble to the same extent in ether-alcohol, acetic ether,
acetic acid, or wood-spirit. On treatment with con-
centrated nitric and sulphuric acids, both the trf- and
tetranitrates are converted into pentanitrate and hexa-
nitrate. Potassa and ammonia convert them into
dinitrate."

"Cellulose dinitrate, C„H„0,(NO,),, is formed
by the action of alkalies on the other nitrates, and
also by the action of hot dilute nitric acid on cellu-
lose. The dinitrate is very soluble in alcohol-ether,
acetic ether, and in absolute alcohol. Further action
of alkalies on the dinitrate results in a complete
decomposition of the molecule, some organic acids
and tarry matters being formed."

The next after Eder to increase our knowledge of
the character and relationships of the members of the
nitro-cellulose series was M. Vieille (Comptcs Rendus,
95, 132), the eminent French savant, whose efforts (in
collaboration with M. Sarrau) were crowned with
success in the production and establishment of
the manufacture of a successful smokeless powder in
France. M. Vieille's researches were published in
part in the French official journal of explosives, the
Memorial des Poudres et SalpStres,* a translation of

""Rechcrches sur U Nitrification du Colon," by M. Vleille,
Iiig^nieuT des PoDdres et Salpftres, Vol. II., iSS^; Paris:
Gauthiera-Villars et Fils.

r:,9,N..<ib, Google

EARLIER VIEWS AS TO NITRO-CELLULOSE IJ

the article referred to constituting Appendix I of the
present work.

Vieille's method consisted in selecting acid mix-
tures of specified standard strengths, nitrating under
regularly controlled conditions as to mass, time, and
temperature, determining the nitration of the resul-
tant products, and plotting upon diagrams the resul-
tant nitrations as referred to the strengths of the acid
mixtures used to produce them. In this manner
he was enabled to recognize a tendency of nitration
towards groupings or discontinuities, rather than
towards progressively increasing nitration, advancing
in measure with increase in strength of acids ; and he
interpreted this tendency as indicating the existence
of a number of definite cellulose nitrates. He sum-
marizes the results of his work as follows :

"In order to account completely for the different
changes groupings, discontinuities) by the production
of nitro-products corresponding to definite formulae, the
equivalent of nitro-cellulose must be quadrupled. Nitro-
celluloses corresponding to such formula: agree with
the theoretical yields of nitrogen dioxide per gram of
material indicated in the following table, and which
correspond either to the discontinuities to which we
have alluded, or else to a change of physical properties. "

While Dr. Eder formulated six varieties of nitrated
material, doubling the coefficients of cellulose by
writing it C„H„0,., instead of C,H„0., M. Vieille
formulates no less than eight compounds, to express
which he quadruples coefBcients, writing cellulose as
C„H„0„. He thus obtains :

D,g,t,.?<ii„GoogIe

U O O (S

OO DO ooo o
5-5, 5.5. 555. 5
qq qq qqq q

r:,9,N..<ib, Google

EARLIER VIEWS AS TO NITRO-CELLULOSE 17

To illustrate the accordance of theory with prac-
tice, the content of nitrogen (dioxide), as it should
exist according to theory, is compared in each case
with that actually determined from practical experi-
ment. From the above there would appear to be
two varieties of gun-cotton insoluble in ether-alcohol,
two varieties of soluble nitro-celluloses, and a number
of varieties of nitro-celluloses of lower nitration. M.
Vieille's paper was published shortly after the official
announcement by the French Government of the de-
velopment and successful establishment of the manu-<
facture of an efficient smokeless powder, these results
being the declared fruits of M. Vieille's researches,
and it is therefore authoritative.

The points to which attention are especially called
in M, Vieille's work are the quadrupling of the expo-
nents of cellulose, and the formulation of as many as
eight varieties of its nitro-dcrivatives.

The abandonment of the old types of smoke-form-
ing powders that had been in use for hundreds of
years, and the substitution therefor, by the French
government, of a new and efficient smokeless powder,
was a step that naturally attracted the attention of all
civilized powers. The composition of the French
powders and their methods of manufacture remained
carefully guarded secrets. Efforts to achieve similar
results were at once inaugurated in other countries,
and the period of inactivity following the abandon-
ment of efforts to employ gun-cotton as a propellant
gave way to one of marked activity in all that related
to the study of explosives. Shortly after the an-

D,g,t,.?<i I,, Google

18 SMOKELESS POWDER

nouncement of the results obtained in France, the
Russian government commissioned Professor D, Men-
deWef, a chemist who had already achieved world-
wide reputation as the expounder of the Periodic
Law of existence of the elements, to conduct a series
of researches with a view to the production of an
efficient smokeless powder for Russia. As the result
of his labors Professor Mendel6ef succeeded in de-
veloping a powder called by him " pyrocollodion,"
which proved satisfactory, and which was adopted
in Russia for use in arms of all calibres. As in the
case of its predecessor in France, the composition and
method of manufacture of pyrocollodion remain care-
fully-guarded national secrets. Outlines of ballistic
results have been published, however, and it is by
these that the next light is thrown upon the composi-
tion of nitro-celluloses.

The scope of Professor Mendel^ef's work, and the
character of the analytical methods followed by him,
may be ascertained from an examination of a paper
published by him, my translation of which constitutes
Appendix II of the present work. In relation to
the structure of the nitro-celluloses he states :

" In all aldehydes, beginning with the formic and
the acetic, a tendency towards polymerization is to be
noted, due, doubtless, to the property of aldehydes
of entering into various combinations (with H,0,
NaHSO, , etc.) ; whence the composition C,H„0, ,
containing an aldehyde grouping, should also possess
this property, so far as relates thereto. We may
therefore safely assume that the molecular composi-

D,g,t,.?<l I,, Google

EARLIER VIEWS AS TO NITROCELLULOSE 19

tion of cellulose, judging from its properties, is poly-
merized, i.e., it is of the form C„H„,0„, where « is
probably very great."

It will be seen from the foregoing that in their ef-
forts to explain the atomic constitution of nitro-cellu-
lose, investigators have invariably been led to increalse
the common multiple of the elements entering into
the composition of cellulose, until finally Mendel^ef
states as his opinion that this multiple may be veiy
great through reason of the presence of certain ten-
dencies towards polymerization. It is interesting to
observe how different chemists have been led to es-
tablish conclusions as to the existence of compounds
corresponding to the formulse they have written.
Eder dissolves out of gun-cotton its soluble content,
and as the result of the analysis of the remaining por-
tion writes its formula as double tri-, or hexanitro-
cellulose, C„H„(NO,),0„; he isolates from cotton
treated with weaker acids, a compound corresponding
in content of nitrogen to what a body of constitution
C„H„(NO,),0„, a pentanitro-cellulose, should give,
and obtains through the agency of solution a nitro-
cellulose precipitate satisfying the desired conditions.
He also obtains, by employing acids of still further
reduced strengths, a body of variable composition
which he regards as a mixture of tetra- and trinitro-
celluloses, but does not succeed in isolating the two
distinct bodies from the mixture. Vieille employs
mixtures of acids increasing in strength progressively;
continues the process of nitration through a period of
time sufficiently long to insure the total conversion of

D,g,t,.?<i I,, Google

20 SMOATELESS POWDER

the cellulose into nitro-cellulose (as shown by the em-
ployment of a solution of iodine in potassium iodide
as an indicator of free cellulose); refers to coordinate
axes the results of each observation, employing
strengths of acids as abscissae, and numbers of cubic
centimetres of nitric oxide evolved as ordinates.
Upon comparing results he notes a tendency towards
the existence of progressive steps in nitration; i.e.,
for an acid varying somewhat above and below a cer-
tain point in strength there appears to be formed a
definite product of nitration. Taking into account the
number of such steps observed and their distances
apart, he formulates the series of compounds enumer-
ated in a preceding paragraph.

D,g,t,.?<i I,, Google

CHAPTER III

THE CONCEPTION OF PROGRESSION IN RELA-
TION TO COMPOSITION AND CONSTITUTION

Cellulose is distinguishable from other materials
employed for purposes of nitration by the possession
of a continuous, complex, and definite cell struc*
ture. The plant producing it has developed by
growth from the protoplasmic state, through influences
of soil, atmosphere, and sunlight; after its death the
cellulose tissues remain, the skeleton of the once liv-
ing organism, possessing a structure bestowed by suc-
cessive growth processes and not by any definite and
general chemical change occurring at any stated time.
It is this remaining tissue, an organization of cells
infinite in their variety and form, that constitutes the
base material employed for nitration. We may pro-
ceed to nitrate it in various ways ; we may first par-
tially destroy or disintegrate the cell structure (con-
vert it into hydrocellulose) ; the nitration may be con-
ducted at various temperatures and continued for
different lengths of time with, the employment of vari-
ous acid mixtures of different strengths, and with the
use of different relative quantities of cotton and acids.
n all of these governing conditions be taken account
of, and if proper allowance be made for their effect,

D,g,t,.?<i I,, Google

22 SJIfO/ir£l£SS POWDER

we may predicate for the nitrated product an exact
composition and exact qualities; if any of them be
overlooked, we lose control of physical character and
chemical composition of the final product.

The method of accounting for the composition of
nitro-cellulose by assuming it to consist of a mixture
of the different members of a graded series of cellulose
nitrates — themselves definite chemical compounds —
was a rational procedure in accordance with established
chemical us^e; yet there existed grave difficulties in
the way of maintaining such views. In the first
place, the members of the series could not be sepa-
rated from one another. Eder was unable to separate
cellulose tetra- and trinitrates. The impossibility of
resolving a given nitro-cellulose into definite quantities
of the various compounds formulated by Vieille, Eder,
or their predecessors, is generally recognized by every
investigator to-day. In the second place, the concep-
tion of a definite period of time being required to ef-
fect nitration is inseparably connected with the forma-
tion of these bodies. Thus properly nitrated gun-
cotton consists of a large quantity of insoluble with a
small quantity of soluble and a very small quantity of
unnitrated cotton; but if nitration be arrested before
completion, there results a mixture of different
quantities of nitrated and unnitrated cotton.

That the nitration of cellulose is a gradual progres-
sive process, advancing from incipiency through lapse
of time towards completion, was the next theory ad-
vanced. This change in treatment of the problem,
which virtually led to the abandonment of the old

D,g,t,.?<i I,, Google

PKOGFESSION 23

simple formulation advocated, is discussed with great
clearness by M. Bruley, a French Government chem-
ist, in a paper entitled " Sur la Fabrication des Colons
Nitres," published in the Memorial des Poudres et
Salpfitres (Vol. VIII, 1895-6), my translation of which
constitutes Apcndix III of the present work.

For purposes of elucidation, Bruley's work will be
considered comparatively, in relation to what has been
accomplished by others. The first investigators
treated cellulose with nitric acid direct, and obtained
a product to which they endeavored to ascribe a for-
mula ; their successors demonstrated the existence of
more than one variety of nitro-cellulose, and formulated
a series of compounds. The various acid mixtures
employed in these researches may be divided into two
classes: those composed of nitric acid and water taken
in various proportions, and those containing sulphuric
acid in addition to nitric acid and water. It was un-
derstood how the absorptive action of the sulphuric
acid rendered possible the formation of cellulose ni-
trates of higher nitration than those that could be ob-
tained by the employment of concentrated nitric acid
alone. But mixtures of concentrated nitric and sul-
phuric acids necessarily contain water, anhydrous sul-
phuric acid being a solid and anhydrous nitric acid
being impossible to prepare ; while with the more
highly diluted mixture of the two acids cellulose
nitrates identical with those formed with nitric acid
and water alone could be formed ; therefore the widest
range of nitration resulted from the employment of

D,g,t,.?<i I,, Google

24 SAfOKSLSSS POWDER

mixtures containing nitric and sulphuric acids and
water.

Vieille had already studied the nitro-products
formed by the use of mixtures containing various pro-
portionate quantities of nitric and sulphuric acids of
definite strengths. Bruley's investigations covered the
broader field resulting from the employment of mix-
tures of the three elements, in which the quantity pres-
ent of each clement varied in all practicable proportions
in reference to the quantities of the other two. The
scope of the latter work may be graphically indicated
as follows:

IS.

[

f ,

X"

?f:innlnm„„!; ln„Iu„l„In„lml„„lM,;„.

^ X

D,g,t,.?<i I,, Google

PROGRESSION 2$

Let ox and OV he co6rdinate axes. On OV lay

off OV, which divide into one hundred equal parts;

and let OY" represent the number of parts of nitric

acid to one hundred parts of sulphuric acid. Then

Y"X"' , parallel to OX, will be the locus of all points

corresponding to mixtures in which the amounts of

nitric and sulphuric acids present bear the definite

OY"
ratio YTyi to each other. On OX lay off OX and

divide it into one hundred equal parts, and let OX"
represent the number of parts of water to one hundred
parts of sulphuric acid. . Then X" F'", parallel to Y,
will be the locus of all points corresponding to mix-
tures in which the quantities of water and sulphuric acid

OX"
present bear the definite ratio „„, to one another.

The point P, in which the lines Y"X'" and X" y"
intersect, corresponds to a mixture containing definite
quantities of nitric acid, sulphuric acid, and water.
The area OY'OX' is a rectangle, every point of which
corresponds to some one combination of the three
elements. M. Bruley explores this area by choosing
a number of approximately equidistant points dis-
tributed over its surface, preparing the acid mixtures
corresponding to them, and determining the nitration
and solubility of the nitro-celluloses prepared from
these mixtures. Proceeding in this manner, and join-
ing points of equal nitration, he maps out a series of
parallel or nearly parallel curves, between which are
included areas of equal or similar solubility. The fol-

r:,9,N..<ib, Google

SMOKELESS POWDER

lowing diagram, taken from M. Bruley's work, illus-
trates the method :

IF WATEB TO iOOFARTSOFaULPHUFlIC

The Roman numcTal is the serial number of cTperimerl; the
npper Arabic numeral, the nitration in cubic centimetres of KOi,
the second, the solubility; ftod the third, when given, the vis-

The nearer the points corresponding to nitrations
lie to the line Ef, which is the locus of mixtures con-

D,g,t,.?<i I,, Google

PROGHMSSIOJ^ 27

taining the least possible quantities of water, the
higher the nitrations. The area is divided into belts
corresponding to mixtures forming insoluble nitro-
celluloses, " intermediate " nitro-celluloses, collodions
of higher and of lower nitration, and "friable" cottons.
The published investigations do not consider mixtures
containing more than 5 $ parts of nitric to 100 parts of
sulphuric acid, M. Bruley stating that mixtures con-
taining more than this relative proportion of nitric
acid are " not practicable commercially from their in-
creased cost " ; nor those containing less than 1 5 parts
of nitric to 100 parts of the sulphuric acid present;
in these nitration proceeds with exceeding slowness.
Similarly, mixtures containing less than 35 per cent.
of water, compared with the quantity of sulphuric acid
present, embrace all those capable of producing nitra*
tions higher than those of "friable" cottons; while
the lower limit of water is fixed by the strength of
the strongest acids commercially obtainable.

Besides nitration and solubility, a new characteristic
of the nitrated product is here introduced, — viscosity,
— as determined by the rate of flow, in drops per min-
ute, through a standard orifice, of a standard solution
of the collodion under examination. M. Bruley
states that increased temperature of nitration, as well
as continued pulping and washing in warm water,
all have the effect of diminishing the viscosity of the
collodions formed from nitro-cellulose ; but he does
not discuss the practical bearing of this fact on the
manufacture of colloids.

M. Bruley also discusses briefly relations of time

r:,9,N..<ib,G00gle ■

28 SSfOKELESS POWDER

and temperature to nitration. The duration of the
reaction is found to be the more prolonged the smaller
the quantity of nitric acid present in the nitrating mix-
ture; an immersion of two hours is found to suffice,
in general, for the production of the soluble nitro-
celluloses; but as much as eight to ten hours are re-
quired to complete the nitration of gun-cotton. A
comparison is made of nitrations conducted at three
different temperatures, employing the same acids and
cotton; and the conclusion is reached that, in the
case of soluble nitro-cclluloses, increase of tempera-
ture during dipping and reaction increases ultimate
nitration and solubility; while for gun-cotton, though
the effect of temperature upon solubility is less dis-
tinctly marked, yet high temperatures have the effect
of increasing solubilities.

During the years 1895 and 1896, I conducted series
of experiments at the Naval Torpedo Station, at New-
port, Rhode Island, with the view to the production
of a nitro- cellulose base suitable for conversion, by
direct colloidization, into an efficient smokeless pow-
der.* The problem presented itself in the form of an
attempt to transform well-known types of nitro-cellu-
loses, with or without the addition of sohd, non-
colloidable ingredients, and by the use of standard sol-
vents, into colloid powders; and it ultimately resolved
into an effort to overcome certain ballistic inconven-
iences, the existence of which was not recognized when
the experiments were begun. In the endeavor to over-

*I bave continued experiment log in tbli field, at Interval*,
ever since this time.— J. B. B.

D,g,t,.?<i I,, Google

come these inconveniences, it became apparent that
there was little hope of preparing from the old mate-
rials a powder capable of fulfilling service require-
ments; and the results, wholly negative, of elaborate
and exhaustive series of experiments with the old
materials, forced me to the conclusion that, if a suit-
able powder were developed, it could only be through
the discovery of a new form of nitro-cellulose capable
of colloidization, and which would possess physical
and chemical properties not pertaining to any hitherto
existing known form of this substance.

As the result of my labors I succeeded in develop-
ing such a new form of nitro-cellulose, which I was
able to convert directly, by colloidization, without
addition of other ingredient, into a colloid smokeless
powder, suitable for arms of all calibres. With this
powder I conducted extended series of experiments,
testing and establishing its keeping quahties, and stand-
ardizing weights of charge and dimensions of grain for
the different calibres of guns. Its manufacture was
established on a commercial scale at the Torpedo Sta-
tion, at Newport, Rhode Island, where the represen-
tatives of the various private powder-manufacturing
establishments were instructed in the method of prep-
aration of the new materia!.* Subsequently these firms
established plants of their own on a scale far larger

• At this time (1894-1897) the Naval Torpedo Sution, at New-
port, Rhode Island, was under the command of Captain George
A. Converse. U. 5. Navy, to whose ability as an adminislralor,
as well as mechanical skill as a specialist, the successful devel-
opment of smokeless powder is largely attributable.

D,g,t,.?<i I,, Google

30 SMOXELSSS POWDBX

than that undertaken at Newport ; and finally an ap-
propriation was secured for the Navy, sufficient for the
erection of a plant lai^e enough to enable this branch
of the service to manufacture an appreciable share of
the powder consumed aSoat.

The steps leading up to the development of the
new nitro-cellulose are cited here in relation to the
light they throw upon ultimate cellulose and nitro-
cellulose structure. Taken in order of approximate
sequence they may be outlined as follows:

1. — Powders were prepared by colloiding insoluble,
soluble, and mixtures of insoluble and soluble nitro-
celluloses in acetone (both varieties of nitro>cellulose
readily colloid in this solvent), forming the resultant
material into strips of different thicknesses, firing
chaises of different weights of each thickness from
standard guns, and tabulating resultant velocities and
pressures. Besides the pure colloids thus obtained
there were experimented with other colloids having in-
corporated into them various percentages of barium and
potassium nitrates, both deposited from solution and
employed in the dry pulverulent state. It was observed
that the addition of the nitrates led to the develop-
ment of smoke, but increased the value of V/P, the
ratio of the maximum pressure to the initial velocity
realized.

2.-— A large quantity of gun-cotton, then stored at
the Torpedo Station, was available for conversion into
powder. It was found that different manufactured
lots of this material produced powders differing widely
in ballistic properties. To determine the cause of

D,g,t,.?<i I,, Google

PROGRESSION 31

these differences, I took blocks of each gun-cotton in
store (some fifty odd lots), washed, dried, and sifted
each sample, — the washing to remove the sodium car-
bonate, — colloided each with the same acetone, formed
the resultant masses into small rectangular grains of
the same dimensions and dried them. I then placed
one- gram weights of each small lot upon slips of glass
and ignited them in the open. The ashes remaining
after combustion differed very greatly among them-
selves, some assuming the form of a fine white resi-
due, others of a sooty mass of unconsumed carbon.
Upon comparing the ash residues with the results of
the complete chemical analyses of the original cottons
subsequently made, I found that, for the cases where
carbon was deposited, the gun-cottons from which the
powder had been made contained an abnormally large
quantity of free unnitrated cotton, the existence of
which had not hitherto been suspected.

3. — Those lots of gun-cotton containing large quanti-
ties of free unnitrated cotton being eliminated, experi-
ments with powders prepared from thd remaining lots
were continued. Ballistic differences were still found to
obtain, although less marked than those primarily ob-
served. Upon comparing the nitration of the original
gun-cottons, — which differed among themselves con-
siderably, ranging between N = 13.4 and N = 12.4, —
with the ballistic results from the powders prepared from
them, it was found that the brusquer powders, which
developed high pressures as corresponding to compar-
atively low velocities, were prepared from gun-cottons
of highest nitration. It occurred to me, therefore,

D,g,t,.?<i I,, Google

32 SMOKELESS POWDER

that uniformity in ballistic conditions might be pre-
served through the maintenance of mean nitration,
i.e., by blending different lots of nitro-celluloses to-
gether, so that the mean nitrogen contents of all
blends should be maintained a constant ; at the same
time providing that dimensions of powder-grains and
weights of charge remained equal. The truth of this
theoretical assumption was abundantly sustained by
the results of practical experiment, and the problem
of the attainment of ballistic uniformity, using gun-
cotton and the old forms of soluble nitro-celluloses as
basis materials for the manufacture of colloid powder,
was solved. Bearing in mind the actual nitrations of
the various lots of gun-cottons on hand, I chose a
mean of 12.75 P^'' cent. N as a standard of nitration,
and blended the successive lots to this figure, adding
soluble nitro-cellulose when it became necessary to re-
duce lots of especially high nitration down to the stan-
dard.

4. — I observed, as the result of experiment, that the
velocity corresponding to a given bore-pressure could
be increased by incorporating oxygen-carriers, such as
barium and potassium nitrates, in certain percentages
into colloid powders; and to such an extent that for
a pressure of fifteen tons a gain of about 300 foot-
seconds could be realized. I attributed this difference
in ballistic effect to an accelerative action due to the
oxidation of the products of combustion of the nitro-
cellulose after their evolution in the bore of the gun
and before leaving the gun, by the gaseous oxides o£

D,g,t,.?<i I,, Google

PROGRESSIO!ir 33

nitrogen evolved from the metallic nitrates.* As the
bodies to which accelerative effect was attributable
were free, inert particles distributed throughout the
substance of the colloid, I ai^ued that free, uncol-
loided gun-cotton distributed throughout an ether-
alcohol colloid of soluble nitro-cellulose would produce
the same effect. Experiments with free gun-cotton as
an " accelerator" proved failures, however, practically
no ballistic difference being observed between the ac-
tion of the ether-alcohol colloid of the soluble, contain-
ing free insoluble nitro-cellulose and certain other col-
loids of the same in which both ingredients were present
in the colloid state. The fact was that both the sol-
uble and insoluble forms of nitro-cellulose were, in
both cases, consumed away at practically the same rate.
5. — The effort to prepare powders from colloided
soluble nitro-celluloses into which uncolloided insoluble
nitro-cellulose was incorporated as an accelerator, led
to extended series of experiments with ether-alcohol
colloids. These proved at first difficult to manufacture,
but, once prepared, were found manifestly superior to
the acetone colloids, as they were extremely tough
and well capable of resisting disintegration in the gun
at the instant of firing, — in which regard the brittle
acetone colloids had not proved altogether satisfac-
tory. Actual experiments in firing had also shown
that the greater the quantity of uncolloided (insoluble)

*See Appendix IV, which is a reprint of my paper entitled
" Development of Smokeless Powder," published in the Proceed-
ings of the U, S. Navai Inst., in which the subject of acceleration
is treated at some length.

D,g,t,.?<ii„GoogIe ■

34" SMO^£LESS POWDES

nitro-cellulose present in an ether- alcohol colloid
powder, the brusquer the powder proved, developing
a higher bore-pressure as corresponding to the muzzle
velocity realized. But, in order to maintain a standard
nitration, — explosive strength, — it was necessary to
have present always a considerable quantity of the un-
colloided (insoluble) form of nitro-cellulose. As this
was objectionable for the above reason, I therefore
began experimenting, to see how far the nitration of
the soluble nitro-cellulose could be raised, — with the
view of minimizing the amount of insoluble nitro-
cellulose that would be required

6. — I also made investigations in another line, and
conducted firing trials with a series of powders pre-
pared from n it ro-hydrocellu loses. A note upon the
constitution of this body may be pertinent here.

When cotton is exposed to the action of hydro-
chloric acid, in the form of gas or of concentrated
aqueous solution, it undergoes a change of form and
composition, being converted into a material known as
hydrocellulose, the composition of which has been
variously regarded. Viewed as a substitution product,
it is formulated as a cellulose hydrate (Girard, cited by
Cross and Bevan); considered physically, it appears to
consist of an aggregation of fragments of the cells
from which the original cellulose was built up. The
fibres seem attacked along planes where their sub-,
stance is most readily susceptible of decomposition by
the acid and are separated from one another; the ac-
tion of the acid appears to be a cutting of cell-Joints
over planes of weakness, whereby the fibres are di-

D,g,t,.?<i I,, Google

PKOGJlESSlOf/ 35

vided into small lengths which are clearly visible un-
der the microscope. (There would thus seem to be
some portions of the cell more readily susceptible to
attack than other portions.) If the process be incom-
plete, partial separation only occurs, long unattacked
fibres remaining in quantity.

Samples of nitro-hydrocellulose, wholly soluble in
ether-alcohol, of nitration as high as 12.6 to 12.7
per cent., were obtained by nitrating hydrocellulose
in the acid mixtures I was employing to prepare
directly mixtures of insoluble and soluble nitro-cellu-
lose from cotton. This led to extended series of trials
of powders, of both the accelerated and the unaccei-
erated types, containing different quantities of the two
varieties of nitro-hydrocelluloses in various propor-
tions, with a view of investigating their stability and
their ballistic properties.

On account of their extreme brittleness, these col-
loid powders proved too brusque, and experiments
with them were abandoned. They also failed in cer-
tain cases to develop normal stability.

7. — The observation of certain remarkable phenom-
ena connected with the effect of decrease in tempera-
ture in promoting the solution and colloidization of
certain forms of nitro-cellulose in certain solvents, —
to which reference is made in detail in a subsequent
portion of this work, — led me to take up the consider-
ation of temperature, as an important factor in the con-
trol of the character and degree of nitration. I con-
ducted extended series of experiments in which cotton
was nitrated in various acid mixtures at temperatures

r:,9,N..<ib, Google

36 SMOSTELESS POWDER

ranging between o* C. and 80° C. The result of these
experiments was the development of pyrocellulose, — a
form of soluble nitro-cellulose of high nitration, which,
for a given weight of its substance, converted into
colloid grains of standard dimensions and dried, de-
veloped, when fired from the standard gun, the high-
est muzzle velocity, as compared with a given limiting
bore pressure.

The results of the observations in this regard may
be briefly summarized as follows:

The physical and chemical, characteristics of prod-
ucts of nitration are subject to radical modi6cations,
through variation of temperature at which the reac-
tion is conducted. Increase of temperature has the
effect of raising the nitration of both the soluble and
the insoluble varieties, and would appear also to in-
crease the percentage of the soluble component in a
blend of the soluble and insoluble varieties. The heat
employed may be derived from two sources: (i) that
evolved during the exothermic reaction of the nitra-
tion of cellulose; (2) that which is supplied from ex-
ternal sources to additionally raise the temperature of
"the nitrating mass. If the temperature of the nitrat-
ing mass be raised above a certain point, the structure
of the cellulose is attacked, and the nitro-celluloses
cease to form, the materia! dissolving in the acid, with
the resultant formation of nitro-substitution bodies of
other genera, such as the nitro- saccharoses; or else,
direct decomposition of the nitrated body ensues,
with evolution of copious fumes of nitric-oxide gas.
The chemical and physical phenomena attending

D,g,t,.?<i I,, Google

PROGRESSWI^ 37

both the decomposition and formation of nitro-cellu-
loses are largely controlled by temperature. Thus,
the explosive force of gun-cotton is greatly reduced
by freezing the latter. Gun-cotton saturated with
liquid air is not only not an explosive, but is practically
a non-combustible; while non-nitrated cotton under
similar conditions is a violent explosive.*

Again, as will be shown hereafter, the extent of solu-
bility of certain nitro-celluloses in certain solvents is
a function of the temperature at which the solution is
undertaken ; so that the relative quantities of the
soluble and insoluble constituents in a mixture of
nitro-celluloses formed at one operation may depend
upon the temperature at which the separation of the
sub-constituents is effected.

* Tb« result of experiments made by me in New York io Octo-
ber, 1899.

r:,9,N..<ib, Google

CHAPTER IV

SOLUTIONS OF NITRO-CELLULOSE. THEORY OF
THE CELLULOSE MOLECULE

Cellulose is found to possess, after nitration, a re-
markable property that unnitrated cellulose does not
possess : it dissolves freely in a number of liquids, in
which it is not soluble in the unnitrated state. Of these/^ '
the solvents ethyl ether, ethyl alcohol, ether-alcohQ^ ..
and acetone are of special interest, both from their
connection with the manufacture of smokeless powder,
and from the physical and chemical bearings of their
methods of effecting solutions. From the solutions
the nitro-cellulose forms with them it may be precipi-
tated by the addition of an excess of water or other
liquid in which it is not soluble, in a flocculent form;
and ultimately, after drying, forms a pulverulent mass.
It is to be specially remarked that the nitro-cellulosc
cannot be recovered in its original cellular state; the
process of solution has destroyed its organic structure,
which may not be recovered or recreated.

The process of effecting the solution of the nitro-
cellulose may be regarded as preliminary to the forma-
tion of the colloid. All forms of nitro-cellulose dis-
solve freely in an excess of those solvents, in contact
with smaller quantities of which they form colloids

38

D,g,t,.?<i I,, Google

SOLUTIONS OF NITRO-CELLULOSE 39

directly. If the quantity of solvent be reduced below
a certain point in proportion to the quantity of nitro-
cellulose employed, colloidization ensues without pre-
vious liquefaction ; if the solvent be sufficient in
quantity to effect liquefaction, evaporation of excess
of solvent must precede colloidization ; if the one state
can be produced, the possibility of forming the other
may be predicated.

The line between solution and colloidization is not
to be drawn sharply ; the two states of matter merging
into one another. There are, however, two distinct
sets of progressive steps or series of physical changes,
to be observed, through one or the other of which
these bodies pass in their transformation from the
liquid to the solid state, and which may be expressed
with reference to their progression as follows:

First series: (a) liquid; {b) jelly; (c) elastic mass;
{d) tough colloid.

Second series: (ii) liquid; (*) slime; (<:) plastic mass ;
{d) brittle colloid.

To Series I belong most ether-alcohol colloids; to
Series II, most acetone colloids.

The purpose of the present chapter is to describe
nitro-cellulose solutions, the methods of forming them,
and their characteristics apart from consideration of
their colloidal evaporated residues; and to present in'
relation thereto certain theoretical considerations
throwing light upon the chemical constitution of cel-
lulose and its nitrates. The subjects of colloids, their
properties and methods of formation, will be treated
subsequently.

r:,9,N..<ib, Google

40 SMOHTELESS POWDER

A discussion of the solubility of nitro-celluloses may
best be prefaced by an account of a remarkable prop-
erty of soluble nitro-celluloses in general, especially
characteristic of pyrocellulose and of those forms of
nitro-hydrocellulose soluble in ether-alcohol ; viz. ,
the direct solubility of these bodies in the solvent ether*
when subjected to the influence of cold.

In August, 1896, I conducted a series of experi-
ments with soluble nitro-hydrocellulose of very high
nitration, to determine its adaptability for conversion
i.nto smokeless powder; this material, colloided in
ether-alcohol and dried, had given promise of value as
a progressive explosive.

Upon a very warm Sunday afternoon, I visited a
dry-house in which a small tray of soluble nitro-hydro-
cellulose, of high nitration (N 12. 44-), was exposed
to a moderate drying temperature. Removing about
one gram of the amorphous gray powder from the dry- .
ing-tray, I introduced it into a tfst-tube, which I
tightly closed with a rubber stopper to prevent the
absorption of moisture. I then visited the chemical
laboratory and partly filled the tube with what I sup-
posed to be ether-alcohol. To my disappointment
the precipitate did not dissolve. Upon agitation, it
diffused itself throughout the liquid, but rapidly settled
to the bottom, in its original pulverulent form, when
brought to rest. I at first attributed this behavior
to excessive nitration, believing the material to con-

•When " eiher " and " alcohol " are referred to wllhont qualU
ficacion, Ihey are iniended to designate ethyl ether and ethjil
alcohol.

r:,9,N..<ib, Google

SOLUTIONS OF NHSOCELLULOSE 41

sist of insoluble instead of soluble nitro- cellulose. Hav-
ing observed, however, during the previous winter that
certain of the insoluble nitro-hydrocelluloses appeared
to exhibit a tendency to enter into solution upon ex-
posure to cold (a portion of the precipitate appearing
to rise in the tube, like a jelly, under the influence
of cold), it occurred to me to try the effect of a salt-
and-ice freezing mixture upon the tube and its con-
tents. I therefore niixed a small quantity of salt and
ice in a beaker, into which I introduced the tube in a
central vertical position. To my great satisfaction,
the whole of the precipitate went rapidly into solution,
forming a yellowish-brown, mobile fluid.

While considering the phenomenon that I had wit-
nessed, I remained seated at my desk, holding the
test-tube enclosed within the palm of my hand. Sud-
denly I noticed that, although I had shifted the tube
into the inverted position (cork downwards), yet the
contents, masked by my hand, had not observed the
law of liquid flow, for the lower uncovered end of the
test-tube, which extended downwards, was empty.
Carefully opening my hand, I was surprised to find
that the contents of the tube had condensed into a
dense jelly, which remained fixed in the upper part of
the tube, I re-introduced the tube into the freezing
mixture; its contents liquefied as before, being trans-
formed into a liquid as mobile as maple-syrup; re-
moval from the source of cold and immersion in water
heated to about ioo° F. (38° C), or holding in the
palm of the hand, sufficed to cause the liquid to con-
geal.

D,g,t,.?<i I,, Google

42 SMOJCELESS POWDER

The phenomenon above described related to the
behavior of soluble nitro-hydrocellulose in the pres-
ence of an excess of solvent (ether) when contained in
a sealed vessel which is exposed successively to differ-
ent temperatures ; removal of the cork with subsequent
evaporation of the solvent results in the formation of
a solid colloid residue, non-liquefiable upon variation
of temperature.

After producing the results above described, I next
endeavored to duplicate them. To my surprise, the
soluble nitro-cellulose, which I supposed the same as
that I employed the day before, promptly went into
solution in ether-alcohol at a temperature of about
70° F. Investigation led to the discovery of an un-
fortunate interchange of trays in the dry-house, which
rendered it impossible to repeat with certainty the
experiment cited. There was, therefore, but one
mode of procedure left — to select sample lots from all
the trays, one of which must represent the lot origin-
ally taken, and experiment with them in the presence
of ether-alcohol. Still I was unable to obtain the
original results. It next occurred to me that I might
have employed by mistake some solvent other than
ether-alcohol, and as the result of a day's experiment-
ing, I found that phenomena identical with those
originally developed could be obtained with soluble
nitro-hydrocelluloses using ethyl ether as a solvent.

Experimenting subsequently, 1899-1900, to ascer-
tain whether the above phenomena were peculiar to
nitro-hydrocelluloses, or whether they were character-
istic of all soluble nitro-celluloses, I found:

D,g,t,.?<l I,, Google

SOLUTIONS OF NITRCCELLULOSE 43

I. — That pyrocellulose could be readily dissolved
in ether upon application of cold.

2. — That all soluble nitro-celluloses acted similarly
in presence of an excess of ether, but that some were
more readily disintegrated by ether upon application of
cold than others.

3. — That if the necessary degree of cold were de-
veloped, soluble nitro-celluloses were not only soluble
to any desired extent in ether, but that they could be
colloided directly therein, without recourse to lique-
faction,

4, — That the addition of a few drops of alcohol in
difficult cases appeared to be equivalent to a lowering
of temperature, i.e., it rendered a given soluble nitro-
cellulose more soluble in ether, in the presence of a
given degree of cold, than it otherwise would have
been.

The problem of nitro-cellulose solution may be ap-
propriately prefaced with the query: Why are certain
forms of soluble nitro-cellulose readily soluble at ordi-
nary atmospheric temperatures in a compound of two
parts by weight of ethyl ether with one part by weight
of ethyl alcohol; whereas, the said forms of nitro-cel-
lulose are not soluble to any appreciable extent, at
ordinary atmospheric temperatures, in an excess of
either ethyl ether or ethyl alcohol, when either is
employed alone as a solvent? The point emphasized
is, why should the single material, soluble nitro-cellu-
lose, prove more soluble in a mixture of two solvents
than in either solvent separately?

II one-tenth of a gram of soluble nitro-cellulose be

D,g,t,.?<i I,, Google

44 SMOKELESS POWDER

placed in a test-tube and covered with, say, 25 c.c. of
ethyl alcohol, and the test-tube be corked and then
violently agitated, it will be found that solution will
not ensue, but that the soluble nitro-cellulose will (if
pulped) gradually settle to the bottom after the tube
is brought to rest, or else remain suspended in an
undissolved state in the liquid. Similarly, the same
quantity of nitro-cellulose will remain undissolved in,
say, twice the same quantity of ether under similar
treatment. If, however, the contents of the two tubes
be combined, the soluble nitro-cellulose will promptly
go into solution in the mixture of the two solvents.

Solubility in ether and solubility in alcohol must be
touched upon before proceeding to the question of
solubility in the compound solvent. It is known that
certain nitro-celluloses of low nitration are soluble in
ethyl alcohol. To this Vieille and Mendekef attest,
and the latter recommends that this fact be taken
advantage of to remove traces of nitro-celluloses of
low nitration from those of higher nitration, the
higher soluble nitro-celluloses not being soluble in
alcohol, at least not at ordinary temperatures.

If it happened that the soluble nitro-celluiose dis-
solved with the same ease in warm alcohol that it docs
in cold ether, the action of the compound solvent
could be accounted for on simple physical grounds.
A mixture of the two solvents might so balance differ-
ences of temperature as to effect solution at some tem-
perature that represented a mean proportional to the
percentage of each solvent in the mixture. The at-
tempt was made, therefore, to dissolve pyrocellulose

D,g,t,.?<l I,, Google

SOLUTIONS OP NITROCELLULOSE 45

in alcohol (95-per cent.) heated to near its boiling
point, but proved unsuccessful. On the contrary,
the tendency was rather away from than toward solu-
tion. This theory was, therefore, untenable.

Having alluded briefly to the effect upon soluble
nitro- cellulose of the individual solvents, (i) ethyl
alcohol, and (2) ethyl ether, the solubility in the com-
pound ether-alcohol solvent may next be considered.

In their work, "Cellulose" (London: Longmans,
Green & Co.), Cross and Bevan, referring to cellulose
and its hydration, state (p. 11):

' ' According to modern views on the subject of solu-
tion generally, and the solution of colloids in particu-
lar, the lines drawn by the older investigators of these
phenomena are of arbitrary value ; gelatinization being
expressed as a continuous series of hydrations between
the extreme conditions of solid on the one side and
aqueous solution on the other."

In their physical forms the solutions of nitro-cellu-
loses in ether and ether-alcohol present striking analo-
gies to the hydrated and gelatinized forms of cellulose
itself. If, as stated, the gelatinized or hydrated form
may be regarded as a continuous series of hydrations
of cellulose, then the colloids can be regarded as what
may be termed a continuous series of etherizations or
alcoholizations of nitro-cellulose. In this manner we
may establish an analogy in point of behavior between
cellulose in the presence of water and nitro-cellulose in
the presence of ether, alcohol, and ether-alcohol.

Referring again to Cross and Bevan, "Cellulose,"
we find (pp. 4 and 5) :

D,g,t,.?<i I,, Google

46 SMOKELESS POWDER

"All vegetable structures in the air-dry condition
retain a certain proportion of water, or hygroscopic
moisture, as it is termed, which is readily driven off at
100° (COf but reabsorbed on exposure to the atmos-
phere under ordinary atmospheric conditions."

"The phenomenon is definitely related to the pres-
ence of OH groups in the cellulose molecule, for in
proportion as these are suppressed by combination
(with negative radicles to form the cellulose esters) the
products exhibit decreasing attractions for atmospheric
moisture. It is to be noted that some of these syn-
thetical derivatives are formed with only slight modifi-
cations of the external or visible structure of the cellu-
lose, of which, therefore, the phenomenon in question
is again shown to be independent."

In parallel to this we may state:

The series of the cellulose esters known as the nitro-
celluloses exhibit at ordinary atmospheric tempera-
tures, with ether and alcohol, effects similar to those
of cellulose with water in what relates to, (i) hygro-
copic moisture, and {2) gelatinization.

In relation to the effect of alkalies on concentrated
solutions — and this is of primary importance in connec-
tion with our subject — Cross and Bevan state (p. 23):

"Cold solutions of the alkaline hydrates of a certain
concentration exert a remarkable effect upon the cellu-
loses. Solution of sodium hydrate, at strengths ex-
ceeding 10 per cent. Na,0, when brought into contact
with the cotton fibre, at the ordinary temperature, in-
stantly changes its structural features, i.e., from a flat-
tened riband, with a large central canal, produces a

D,g,t,.?<i I,, Google

SOLUTIONS OF fflTROCELLVLOSE 47

thick cylinder with the canal more or less obliterated.
These effects in the mass, e.g., in cotton cloth, are
seen in a considerable shrinkage of length and width,
with corresponding thickening, the fabric beconjing
translucent at the same time. The results are due to
a definite reaction between the cellulose and the alka-
line hydrates, in the molecular ratio C„H„0,j: 2NaOH,
accompanied by combination with water (hydration).
The compound of the cellulose and alkali which is
formed is decomposed on washing with water, the
alkali being recovered unchanged, the cellulose ap-
pearing in a modified form, viz., as the hydrate
C„H„0,..H,O. By treatment with alcohol, on the
other hand, one half of the alkali is removed in solu-
tion, the reacting groups remaining associated in the
ratio C„H„0,. : NaOH. The reaction is known as
that of mercerization, after the name of Mercer, by
whom it was discovered and exhaustively investigated.
Although, however, it aroused a good deal of attention
at the time of its discovery, it remained for thirty years
an isolated observation, i.e., practically undeveloped.
Recently, however, the alkali cellulose has been made
the starting point of two series of synthetical deriva-
tives of cellulose, which must be briefly described."

"From the points established by Mercer in connec-
tion with this reaction, the following may be further
noted :

"At ordinary temperatures a lye of 1.225-1.275
sp. gr. effects 'mercerization' in a few minutes;
weaker liquors produce the result on longer exposure,
the duration of exposure necessary being inversely

D,g,t,.?<i I,, Google

48 SMOKELESS POWDER

as the concentration. Reduction of temperature pro-
duces, within certain limits, the same effect as in-
creased concentration. The addition of zinc oxide
(hydrate) to the alkaline lye also increases its activity.
Caustic-soda solution of l.too sp. gr., which has only
a feeble 'mercerizing' action, is rendered active by
the addition of the oxide in the molecular proportion
Zn(OH), : 4NaOH."

Two points in the above merit special attention in
connection with our subject. They are :

I, — The removal of one-half of the alkali on treat-
ment with alcohol, the reacting groups remaining as-
sociated in the ratio C..H„0,. : NaOH.

2. — The acceleration, on exposure to a lye of
1. 225-1. 275 sp. gr., of the process of " mercerization "
by reduction of temperature. Here is presented an
analogy to the increased solubility of nitro-cellulose in
ether and ether-alcohol upon application of cold.

In referring to the production of cellulose thio-
carbonates and to the quantitative regeneration of
cellulose from solution as thiocarbonate, Cross and
Bevan state (pp. 29-3 1) :

"The occurrence of this reaction, under what may
be regarded as the normal conditions, proves the
presence in cellulose of OH groups of distinctly alco-
holic function. The product is especially interesting
as the first instance of the synthesis of a soluble cellu*
lose derivative — i.e., soluble in water — by a reaction
characteristic of the alcohols generally. The actual
dissolution of the cellulose under this reaction we can-
not attempt to explain, so long as our views of the

D,g,t,.?<i I,, Google

SOLUTIONS OF Nimo-CELLVLOSE 49

general phenomena of solution are only hypotheses.
There is this feature, however, common to all pro-
cesses hitherto described, for producing an aqueous
solution of cellulose (i.e., a cellulose derivative), viz.,
that the solvent has a saline character. It appears,
in fact, that cellulose yields only under the simulta-
neous strain of acid and basic groups, and therefore
we may assume that the OH groups in cellulose are
of similarly opposite function. In the case of the
zinc-chloride solvents there cannot be any other de-
termining cause, and the soluble products may be re-
garded as analogous to the double salts. The reten-
tion of the zinc oxide by the cellulose, when precipi-
tated by water, is an additional evidence of the pres-
ence of acidic OH groups ; and conversely, the much
more rapid action of the zinc chloride in presence of
hydrochloric acid indicates the basicity of the mole-
cule, i.e., of certain of its OH groups. On the other
hand, in both the cuprammonium and thiocarbonate
processes there may be a disturbance of the oxygen
equilibrium of the molecule ; and although there is no
evidence that the cellulose regenerated from these
solutions respectively is oxidized in the one case or
deoxidized in the other, it is quite possible that tem-
porary migration of oxygen or hydrogen might be
determined, and contribute to the hydration and ulti-
mate solution of the cellulose. But, apart from hy-
potheses, we may lay stress on the fact that these pro-
cesses have the common feature of attacking the cellu-
lose in the two directions corresponding with those of
electrolytic strain ; and it is on many grounds prob-

D,g,t,.?<i I,, Google

50 SStOKELESS POWDER

able that the connection will prove casual and not
merely incidental." *

It is the feature of double attack upon the cellulose
that suggests the cause of the increased solubility of
the nitro-cellulose in the compound ether-alcohol sol-
vent, as compared with its relative solubility in the
ether and alcohol separately. In the case of the
" mercerized " cellulose we observe that a removal of
one-half the alkali is effected by the alcohol treat-
ment. The reaction of the alcohol here relates to the
basic OH groups, the alkaU appearing to be retained
as a base in the groups of acid reaction. A lower
temperature facilitates the " mercerization " process;
this may be interpreted into the statement that raising
the temperature of the molcule beyond a certain point
retards the process. So, in the case of the increased
solubility of soluble nitro-cellulose in ethyl alcohol at
low temperatures, the employment of artifical cold
accelerates the process of solution. We may here as-
sume that the material, from its dual character, is
under an electrolytic strain, from which it is removed
by application of cold (abstraction of heat) ; the alco-

* Referring to the character of the regeaerated cellulose in
comparison with the original material, Cross and Bevan state,
inttr al. :

" (l) lis hygroscopic moisture, or water of condition, is Some 3 to
4 per cent, higher, viz., from 9 to 10.5 per cent.

" (a) Empirical cemposition. The mean results of analysis show
C = 43.3 per cent,, H =6,4 per cent., which are expressed bjt the
empirical formula 4CiH,tOt,H]0."

It will be observed that the regenerated material is an amor-
phous hjdrocellulose.

D,g,t,.?<i I,, Google

SOLUTIONS OP mTRO-CELLULOSE S'

,hoI then attacks and dissolves the basic OH groups;
the structure of the cellulose is destroyed; the acid
groups yield subsequently and enter into solution, to
effect which there may occur, as suggested by Cross
and Bevan for cellulose, a temporary transfer, within
the molecule of nitro-cellulose, of hydrogen and oxy-
gen ; and the whole substance finally yields to alco-
holization in a manner analogous to that by which
cellulose itself yields to hydration.

Similarly, for the increased solubility of soluble
nitro-cellulose in ethyl ether at low temperatures, the
employment of artificial cold accelerates the process
of solution. The ether dissolves the acid OH groups
(in contradistinction to the action of the alcohol,
which attacks the basic OH groups); the structure of
the cellulose is destroyed ; the basic groups yield sub-
sequently, to effect which there occurs a transfer of
hydrogen and oxygen within the molecule in a direc-
tion opposite to that in which it occurs in the previ-
ous case, and the whole substance finally yields to
etherization in a manner similar to that by which cel-
lulose itself yields to hydration.

As bearing upon the theory it may be remarked that
the two solvents, ethyl alcohol and ethyl ether, differ
by H-O-H, since ether, (C.H,), O, + H.O = alcohol,
2C,H.O.

In the case of the mixed ether-alcohol solvent we
subject the cellulose in the one operation to the double
tendency to disintegration. The necessity for the
application of cold (or the absorption of heat) to ef-
fect the necessary arrangement of the H-O-H groups,

D,g,t,.?<i I,, Google

52 SMOKELESS POWDER

as they may be styled, i.e., to strain them into basic
and add relations, is no longer required, for the double
attack in two directions, corresponding to those of
electrolytic strain, is provided for by the parallel double
composition of the ether-alcohol solvent.

There is reason for supposing that the above-de-
scribed reaction is not limited in its occurrence to
forms of soluble nitre-cellulose alone, but that it
obtains equally for the insoluble varieties. If the
theory be correct, then insoluble nitro-cellulose should
be soluble in ether. Macnab has shown that insoluble
nitro-cellulose dissolves in ether-alcohol at a very low
temperature.*

In the fall of 1899, the time that liquid air first be-
came readily obtainable in quantity in New York, I
decided to check Macnab's experiment by employing
this material as a refrigerant; also (i) to experiment
with a view of ascertaining whether insoluble nitro-
cellulose of very high nitration in its unpulped fibrous
form, — the form in which it might be supposed to
oppose a maximum resistance to the disintegrating
action of solvents, — would not actually go into solu-
tion in ethyl ether alone under influence of extreme
cold; and (2) to determine how far nitro-cellulose is
soluble in absolute ethyl alcohol. The ether em-
ployed in these experiments was Squibbs', C.P., for

* See experimeals cited by Gultmann in his article " Manufac-
ture of Explosives," published in the Journal of the Seciity of
Ckimual Industry, London, June 30. 1S94 ; also p. 404 appendix 4
to his recently published vorb, "Manufacture of Explosives,"'

D,g,t,.?<i I,, Google

SOLUTIOffS OF NITSO-CELLULOSE 53

anaesthesia; the insoluble nitro-cellulose was gun-
cotton of high nitration (N = 13-4+) and purity, in
the unpulped state.

The solvent employed in the alcohol experiments
was absolute ethyl alcohol; the nitro-celluloses were
(i) soluble nitro-hydrocellulose of nitration, N ii-4J<;
(2) soluble nitro-hydrocellulose of N I2,6;<; (3) pulped
pyrocellulose, N i2.42<iC; and (4) unpulped gun>cotton
of high nitration, N \},.£t^.

Experiment I. — I placed about one-tenth gram of
gun-cotton in a test-tube, poured over it 25 c.c. of 2 : i
ether-alcohol, tightly closed the tube with a rubber
stopper and immersed it in a vessel containing about
750 c.c. of liquid air. When the contents of the tube
became sufficiently cooled, the gun-cotton went read-
ily into solution, forming a clear mobile liquid of a
honey-yellow color. I found that the gun-cotton re-
mained in the colloid form after the removal of the
tube from the liquid and the subsequent heating of its
contents to the temperature of the atmosphere. On
removing the tube from the liquid-air bath, uncorking
and allowing the contents to evaporate, the residue
formed a tough, homogeneous amber-colored film.

Experiment II. — Having succeeded readily in col-
loiding insoluble nitro-cellulose in ether-alcohol, I next
decided to ascertain whether it were possible to col-
loid it in ether alone. I placed one-tenth gram of the
gun-cotton in a test-tube, poured over it about 25 c.c.
of ether, tightly closed the tube and immersed it in
the same quantity of liquid air as before.

Upon sufficiently reducing the temperature, the

f UNIVERSITY

54 SMO/CELESS POWDER

contents of the tube became solid and the ether froze
into a snow-white mass. On removing the tube from
the cold and allowing the ether to melt, I found that
the gun-cotton had disintegrated and gone into solu-
tion, forming a mobile slightly clouded liquid with a
yellowish tinge. The gun-cotton remained in solution
after the withdrawal of the tube from the liquid air
and the subsequent heating of its contents to the
temperature of the atmosphere. On removing the
tube from the liquid-air bath, uncorking and allowing
its contents to evaporate, the residue formed a tough,
homogeneous, slightly yellowish colloid.

Experiment III. — About one-tenth gram of each
of the above-mentioned series of nitro-celluloses was
each placed in a separate test-tube and each had
poured over it about 25 c.c. of absolute ethyl alcohol.
The tubes thus partly filled were closed tightly with
rubber stoppers, immersed in liqirid air (for about
two-thirds of their lengths), and allowed to remain
therein for five minutes.*

The contents of each tube froze in about half a
minute and the rest of the time the liquid air was
acting upon the frozen contents. On removing the
tube containing the gun-cotton from the bath and
allowing its contents to melt, the gun-cotton was, to

•The liquid air for these experiments was very kindly fur-
nished me by Messrs. Vandivert and Gardenhire, of 31 Broadway,
New Yorit, pioneers in the development of liquid air in the United
States, I am also indebted to Mr. M. Burger, president of the
company, for his kindness; and especially to Mr, O. Ostergren
of Hew York," one of the original experimenters and developers
of the commercial manufacture of liquid air.

D,g,t,.?<i I,, Google

SOLUTIONS OF NITBO-CELLULOSE S5

all appearances, unaltered. This showed that, whether
or not the fibre of the cotton had been attacked, it
was not affected to the same extent by the ethyl
alcohol as it was by the ethyl ether, which, as pre-
viously shown, destroyed the fibre of the gun-cotton,
causing it to go into solution.

The sample of pyrocellulose and the two small lots of
nitro-hydrocellulose in the other tubes were found to
have gone into solution in the ethyl alcohol, through
the action of the cold, the former affording a jelly-
like straw-colored colloid; the two latter, the usual
brownish-yellow colloids.

We may now call attention in parallel to the follow-
ing remarkable reactions ;

I. — That nitro-celluloses dissolve in ethyl ether
under the influence of intense cold.

2. — That nitro-cclluloses, with the apparent excep-
tion of the highly nitrated insoluble variety (this will
be further experimented with later, in the presence of
extreme cold) dissolve in ethyl alcohol under the in-
fluence of intense cold.

3. — That the so-called soluble forms of nitro-cellu-
lose of mean and low nitrations go into solution in a
mixture of ethyl ether and ethyl alcohol at ordinary
atmospheric temperatures.

In connection with the above may be mentioned :

{a) That the various forms of nitro-celluloses seem
more readily soluble in ethyl ether than in ethyl alcohol.

{b That a mixture of two volumes of ethyl ether
to one of ethyl alcohol seems to extract at ordinary
atmospheric temperatures the greatest quantity of

D,g,t,.?<i I,, Google

56 SJifOKELESS POWDER

soluble constituents from a mixture of the two forms
of nitro-cellulose (soluble and insoluble as formed by
one dipping of cotton.)

It now remains to consider the theory of compo*
sition of cellulose and nitro-cellulose from the chemical
standpoint. In this connection it is necessary, first of
all, to emphasize the fact of the similarity in compo-
sition of the cellulose and the nitro-cellulose molecule.
The latter is formed from the former by the substitu-
tion, for a certain number of replaceable hydrogen
atoms, of the same number of equivalents of nitryl —
NO,. The effect of the introduction of nitryl into the
substance of the cellulose is an apparent weakening
of the stability of the latter, rendering it susceptible
of decomposition in a number of additional ways, and
making actual tendencies to decomposition, traces of
which exist in the original material, but which are held
in control by stronger counteracting tendencies derived
from other sources.

For the sake of simplicity the formulae presented in
what follows will be those of cellulose. It is to be
understood that whenever questions arise referring
directly to nitro-cellulose, such as solubility in ether
or ether-alcohol, the cellulose molecule as presented is
to be considered as tacitly representing nitro-cellulose,
without actual expression of the substitution of NO,
in the replaceable hydrogen atoms.

Bearing the above in mind, the following additional
facts may be taken advantage of in formulating a
theory of the composition of the cellulose and the
nitro-cellulose molecule ;

D,g,t,.?<i I,, Google

SOLUTIONS OF NITSO-CELLULOSE 57

1. — The two solvents of soluble nitro-cellulose, ethyl
ether and ethyl alcohol, differ in composition by H-O-
H. Like H.O, they may be written (C,H.),0 and
C.H.OorC,H..O.H.

2. — Cellulose, C„H„0,„ is transformed by treatment
with alkali in aqueous solution into C„H„0„.2NaOH.

3- By subsequent treatment with water it is con-
verted into cellulose hydrate, C„H„.0„.H,0.

4.— By treating C„H„0,..2NaOH with alcohol,
C,H,0, the former is converted into the mercerized
form, C„H«0„.NaOH, with half the alkali removed.

To account for the occurrence of reactions (2) and
(3), the composition of the cellulose molecule is
regarded as doubled, i.e., raised from C,H„0, to
C„H„0„. (4) is of especial importance and interest, as
it exhibits the action of alcohol upon non-nitrated cel-
lulose; establishing a basis for the assumption that the
action of the double ether-alcohol solvent upon nitro-
cellulose is based upon the original composition of
cellulose itself.

Assuming a duality of composition as indicated (l)
by its basic and acid reactions; (2) by its greater solu-
bility in the compound solvent; (3) by the H-O-H
difference of the components of the original compound
s61vent ; and (4) by the creation and absorption of the
H-O-H groups in the formation of cellulose hy-
drates and alkaline compounds, we may proceed as
follows :

If alcohol is capable of effecting the solution of a
nitro-cellulose, it must effect the solution of both its
components or resolve itself into two &ub- components,

D,g,t,.?<ii„Google^

58 SAfOJCELESS PQWDBR

each reacting on one sub-component of the nitro-cel-
lulose, in order that it may effect the solution of the
whole. Under the latter assumption, we may con-
sider alcohol,. C,H,0, as having the composition

H H

H H

which may be divided into

H H

C< and >c

I ^H H^ I

H H

Similarly, we may regard ethyl ether, (C,H,),0, as
having the composition

H H

I I

H— C— O — C— H

I I

H— C— HH— C— H
I

H H

capable of dividing into

H H

I I

H— C— — O— C-H

I and I

H— C— H H— C-H

I I

n,9,N..db, Google

SOLUTIONS OF NITRO-CELLULOSE 59

If such a tendency as illustrated above exists, it
will become a reality through the disintegration of
equivalents which, in combination, correspond to a
molecule of water, H,0.* The removal of one-half of
the alkali from cellulose in the mercerization process
is effected by the action of the alcohol upon the
basic groups therein ; the molecule ot cellulose should,
therefore, be represented so as to permit a resolution
of the original material into acid and basic sub-com-
ponents through the disintegration of the water-
groups. Under this assumption, we may write cellu> -
lose as

• It will be obierv«d that the constituents of water, H-O-H,
form the central Unking gfoup in each of Ihe expressions
H H

H H I I

I yQ-^ I H— C— O — C— H

CC /C and I

I ^HH' I H— C— HH— C— H

I
H H

D,g,t,.?<i I,, Google

60 SMOKELESS POWDER

which would resolve into

H H

I I

H— C— O— H H— O— C— H

l/H I

c< o=c

C— O— H H— O— C

Form I. II II

C— O— H H— O— C

I H. I

c=o >c

H— C— O— H H— O— C— H
I I

H H

H H

I I

-C— O— H H— O— C— H

I ,

o=c

<

C— O— H H— O— C

C— O— H

K

I nh

0=C
H— C— O— H H— O— C— H

The molecule as above written contains double cen-
tral carbon bonds, which fact permits it, oh its enter-
ing into combination, to be written as

r:,9,N..<ib,G00gIe

SOLUTIONS OF KITRO-CELLVLOSE

H H

H— C— O— H H— O— C— H

— C— O— H H— O— C—

H— C— O— H H— O— C— H

Without radical modification, it may be expressed

I

■C— H

H— C— 0— H H— O— I

H— C— O— H H— O— C— H
H— C— 0-H H— O— C— H

H— C— 0— H H— O— C— H
I I

as corresponding to C„H„0„.

D,g,t,.?<i I,, Google

SMOKELESS POWDEK

ring it, we will obtain

H

H

— C— O— H

H— O— C—

_t_0— H

H_0— C—

k

A

corresponding to C,H„0,.*

This latter form, which is the simplest expression
for cellulose, represents, not the molecule, but the type
unit of cellulose, as it enters into combination,
through its four free single carbon bonds, either with
other similar units, by polymerization, or with other
substances by chemical combination.

* Written tinglr, in a ilmilar form, but with cloied bond*, the
single molecule, CiHitOi, may be expressed ai

Compare also with Cross and Bevan, " Cellulose," p. 38, where,
in reference lo cellulose acetates, it is stated if tbe above formula
(alluding to a formula cited) be established bjr further and ex-
haustive investigation, tbe cellulose unit must be C(H(0.(OHV

D,g,t,.?<l I,, Google

SOlUr/OJVS OF tftTRO-CELLULOSB 63

The multiplicity of the cellulose derivatives and the
generally recognized tendency towards polymerization
already alluded to suggest the further amplification
of the molecule by inter-combination of its units
through connection of their carbon bonds into poly-
meric forms, the type of which may be expressed as
follows :

Such a method of representation possesses a special
interest, as it prepares the way for other considerations.
The actual number of phases for the polymerized
molecule thus expressed may vary from 2 to any
desired number. In the above diagram a S-phase
form is presented for purposes of illustration. The
simple molecule with its four free carbon bonds as

?<i I,, Google

64 SMOKELESS POWDER

presented in each of the five sectors combines with
the simple molecule in each adjacent sector on either
hand. The simplest polymerized form that, under our
theory, can stand alone, is C,,H„0,„ composed of
two "sectors," the carbon bonds in each of which
unite with those of the other.
Thus we have

correcting the form previously written.

The 5-phase molecule, or its polymer, corresponds
to py race llu lose.

It is evident that under such an assumption the
molecule may possess an infinity of phases. There is
no limit to their number. On this assumption, and it

D,g,t,.?<i I,, Google

SOLUTIONS OP NITRO-CELLVLOSE 65

seems to me on this assumption only, may we account
for definite chemical composition of the cellular form
in the plant structure. For we may regard the cell
as built up from an aggregate of molecules of identical
composition but of progressively-varying numerical
phase. The cell may begin with molecules of low
phase and end with molecules of high phase, or con-
versely. Molecules of progressively- varying phase-
magnitude may be deposited in turn from protoplas^
mic matter in particular forms of different density, the
successive evolutions providing for the infinity of cel-
lular structures appreciable to the human eye, which,
in their successive deposition, build up the fibrous sub-
stance of the cell.

It is to be remembered that the graphic represen-
tation of molecular arrangement upon a plane surface,
— space of two dimensions, — cannot be regarded as
more than a conventional device illustrating an ar-
rangement that exists in nature in space of three
dimensions. Nevertheless, the conventional ring-
formed combination of elemental particles shown in
the polyphase molecule strongly suggests the vortex-
ring theory of the composition of matter (as applica-
ble to the molecule). For whatever the atom may be,
the molecule need not be limited in composition to
the simplest collection of the lowest possible number of
atoms capable of entering into combination, but may
be built up from a very great number of the elemental
particles taken together in their proper ratios.* Such

* On this hypothesis the atomic weight of cellulose would be
TCpretented by an average.

D,g,t,.?<i I,, Google

66 Sl^OJfELESS POWr>ER

a molecule would increase in amplitude according to
the number of elemental particles entering into its
composition ; and the thought therefore suggests it-
self, that progressive variation in the amplitude of ike
molecular ring is a characteristic of organic life. Or,
conversely, we may state that we may seek for the
beginnings of organic life, — at least of plant-Hfe, — in
the polymerization of the carbohydrates.

Briefly summing up, the conditions governing the
formulation of cellulose may be stated as follows :

I. — The capability of the expression of the molecu-
lar formula as «(C,H„0,) or C„H,„0,. justifies the as-
sumption that the molecule, may be represented as
composed of n number of similar atomic aggregations
oT the form C,H„0„ these aggregations conjointly
forming the molecule.

2. — Under the assumption that Eder's nitrates repre-
sent limits of nitration In the sense defined by Vieille,
H cannot possess a value less than 2 ; that is, C„H„0„
represents the lowest expression for the molecule.

The fact that 2 : i ether-alcohol dissolves certain
forms of nitro-cellulose at ordinary atmospheric tem-
peratures with greater ease than any other compound
solvent containing ether-alcohol in other than the 2 : i
proportion, tends to show that all the OH groups in
which nitro-substitution takes place are not similarly
placed within the molecule.

4. — The fact that, at very low temperatures, either
ether or alcohol singly will dissolve soluble nitro-cellu-
lose, whereas at ordinary atmospheric temperatures
a mixture of the two solvents is required to effect

r:,9,N..<ib, Google

SOLUTIONS OF NJTRO-CELLULOSE (>J

solution, implies that, under influence of cold (absence
of heat), both ether and alcohol, on the one hand,
nitro- cellulose on the other, may undei^o a certain
atomic rearrangement within the molecule.

5. — If symmetry of arrangement exists in the sub-
components of the molecular section — C,H„0, — per-
mitting the representation of atomic aggregations
which, according to the influences to which they are
exposed, may exhibit acid actions on the one hand,
basic reactions on the other, it would be by groupings .
of the carbon and hydrogen atoms, which are even
in number, around the oxygen atoms, which are odd
in number.

6. — There is good reason for the assumption (basis of
theory of nitro-substitution) that the molecules of both
cellulose and nitro-cellulose are of simitar structure;
that there is no general rearrangement of the atoms of
the cellulose in the process of nitration, but that nitra-
tion is accomplished through the substitution of nitryl
for replacable hydrogen in certain hydroxyl groups, the
said groups retaining, after nitration, the position in
the molecule that they held before nitration, as already
stated. It is upon this assumption that we represent
the molecule of cellulose as typical, both of cellulose
and nitro-cellulose, and do not represent the substitu-
tion of the nitryl in the molcule, unless actually refer-
ring to some specific property of the nitro-cellulose
distinguishing it from the original cellulose.

7, — Under the assumption (i) of the basic and acid,
positive and negative, distribution of the atoms within
the molecule, based upon the conception of the con-

D,g,t,.?<l I,, Google

68 SMOJCELESS POWDER

stitution of the molecule as a double salt, and (2) of '
the action of the compound ether-alcohol solvent upon
nitro-ccllulose at ordinary atmospheric temperatures,
and of the action of both the ether and alcohol sep-
arately upon nitro-cellulose at low temperatures,
we may regard (a) the ethyl ether, (i) the ethyl
alcohol (which possesses the composition but not the
atomic arrangement of an ether [methyl]), and {c)
the nitro-cellulose, which possesses the characteristic
properties of an ether, as all splitting up into dual
sub-groups. The manner in which ethyl ether and
ethyl alcohol could so split up symmetrically is easily
shown ; regarding nitro-cellulose as an ether, we may
seek to split It into sub-groups within the molecule
in a similar manner.

The three type forms may then be presented as fol-
lows:

Etbjrl alcohol Ethyl ether

C,H.O (C,H,),0

(Dnder itmln n neUiTl cihtr)

H H

H H II

,H H^ H— C— O — C— H

C< >C I I

I XO--^ H— C— HH— C— H

H H II

H H

Nitto-cetlulosc
(Ai eipccMed by iis type, celliiloM}

I I

H— C— 0— H H— O— C— H

H— C— O— H H— O— C— H
I I

D,g,t,.?db, Google

SOLUTIONS OF XZTSO-CELLULOSE

69

That all nitro-celluloses are soluble in the compound
ether-alcohol solvent, notwithstanding the wide differ-
ences in temperatures at which solution is effected,
leads me to the conclusion that all nitro-cellulose
molecules are of similar constitution and organization.
That they are of a dual composition is evinced by
their more ready solubility in the compound solvent ;
again the fact that they are all soluble in the single
solvent ethyl ether leads me to the conclusion that
the two halves of the dual molecule are, with respect
to each other, similar, or of similar inverted forms.
Therefore, on page 60, Form I is the correct diagpram
of the separation of the factors, rather than Form il.

We have considered briefly in the preceding the
composition of the molecule in relation to mercer-
ization, polymerization, nitration, and colloidization.
It remains to dwell somewhat more fully upon the re-
actions of nitration and hydration, and to show how
they are reflected in the modified structure of the
molecule.

The type cellulose has been written :

By changing the relative position of atoms of hydro-

D,g,t,.?<i I,, Google

SMOXELESS POWDER

gen, and without altering the constitution of the
molecule, it may be written :

The polymerized molecule is composed of sections of
the type :

H-i-0-« H-0-^J-«

H-C-O-H H-O-C-B

From an examination of the unit of polymerization it

I I

H— C— 0— H H— O— C— H

I ^^^-^ I

will be seen that the atoms of carbon are connected (i),
by single bonds with each other ; (2), with hydrt^en
bonds; (3), with hydroxy! bonds; and (4), with what

may be termed "water bonds," of the form C^

Each carbon atom is connected with two other car-
bon atoms, one on either side. Every third carbon

D,g,t,.?<i I,, Google

SOLUTIONS OF NITRO-CELLULOSE 71

atom is connected with the di-valent " water " radicle
(A). The remaining two of each set of three carbon
atoms are each connected with one atom of hydrogen
and one hydroxyl radicle (B). The symmetrical order
of arrangement of the carbons is — BAB — BAB —
BAB—.

The free carbon bonds of each unit represent poly-
merisation.

The hydroxyl radicles represent nitration^ in the
mean and higher st^es.

The " water" radicles represent mercerizaiion, and
nitration in the lower stage.

The open oxygen bond in the "water " radicle rep-
resents coHoidization by combination of the half mole-
cule of the nitro-cellulose with the half molecule of
the solvent.

Nitration. — The process of nitration may here be
taken up for more extended consideration. The fibrous
cellulose reflects in its chemical behavior a character-
istic of plant life, namely, the possibility of altering
growth conditions through changes of temperature.
The reactions into which it enters may be varied
through the variation of the temperature at which the
said reaction takes place. These changes in rate and
character of reaction as due to temperature are espe-
cially characteristic of nitration, mercerization and
coHoidization ; and doubtless, during the origins!
growth processes of the plant, affect polymerization.
The effect of temperature upon nitration is reflected in
the resultant nitrated product in two ways: (l) in
raising the degree of nitration in proportion to the

D,g,t,.?<i I,, Google

72 SMOXELESS POWDER

increase in temperature (within certain limits) ; and (2)
In increasing and modifying solubilities corresponding
to given nitrations.

Until very recently, our actual knowledge of the
nitration of cellulose may be said to have been con-
fined to the following facts :

I. — That there was a lower limit of obtainable nitra-
tion, somewhere between that represented by the
compounds C„H„0,(OH).(NO,), for which N = 3.80,
and C,.H,.0,(OH). (NO,)., for which N = 6.76.

2. — That there exists an upper limit of attainable
nitration, somewhere near that of the hexanitrate of
Eder, C„H„0.(NO,)., for which N = 14.14.

3'. — That nitration is progressive between these
limits ; and that when detennined at a given tempera-
ture, it advances gradually and progressively from the
lower towards the higher limit, while under certain
conditions it may be made, similarly, to decrease.

4. — ^That somewhere between the attainable limits of
nitration a point is reached (and the point is not con-
stant so far as relates to degree of nitration) where the
nitrated product ceases to be soluble at a given mean
atmospheric temperature in a mixture of ethyl ether
and ethyl alcohol. This fact was utilized to separate
the so-called "soluble" nitrates of celluloses of low
nitration from the "insoluble " nitrates of high nitra-
tion.

Let us consider the formula for the double-type
molecule in connection with the six nitrates for-
mulated by Eder, and let us assume that there has
been isolated from the substance of the cellulose for

D,g,t,.?<i I,, Google

SOLUTIONS OF NITRO-CELLULOSE 73

purposes of experimentation a homogeneous body

Negative
Acid

H-O-O-H H-0-6-H

H-C— O-H H-O-T
H-C-O-H H^-K

H-C-0-H*'H-0-l

Positive

Basic

composed of molecules of the above 2-phase form.
Then, if there are six nitrates, we could form them
successively by substituting nitryl for the replaceable
hydrogen in the " water" and "hydroxyl" radicles of
the cellulose on one side of the molecule. Substituting
thus in the above diagram we would have, for the
highest nitrate

N^ative
Acid

■H-C— O— NO, H-
■H^i-O— NO, H-O-

H-C-O-tNO,

On account of the ready solubility of the lower
nitrates in ethyl alcohol at ordinary temperatures the
maximum efficiency of the 2 : I ether-alcohol, and the
solubility of the highest nitrates in ethyl ether, we
assume that the replaceable hydrogen atoms in the
water radicles are replaced by nitryl first, and that
subsequently the nitro-substitution continues through
the displacement of the hydrogen in the hydroxyl
radicles. If we regard alcohol as connected with the

D,g,t,.?<i I,, Google

74

SJItOXELESS POWDER

positive (basic) side of the molecule, and ether with
the negative (acid) side, we may represent nitration,
for the higher nitrates (say.thehexanitrate), as follows;

Negative
Acid

H-C— O— NOi H-O-fr
I o :,. _J -

O-^O, H-O-fr
O— NO, H-O-C-

O— NO, K-O-C— H

Positive
Basic

Under such conditions, we may formulate the
nitrates of cellulose for the 2-phase molecule as fol-
lows:

Cellulose hexanitrate, C„H„(NO,),0„.

Cellulose pentanitrate, C„0„(NO,),0„.

Cellulose tetranitrate, C„0„(N0.).O,.-

Cellulose trinitrate, C,.H„(NO,),0,..

Cellulose dinitrate, C„H„(N0,),O„.

Cellulose mononitrate, C„H„(NO,)0„.

If we turn from the consideration of the theoretical
2-phase cellulose above represented to that of actual
cellulose, we will find that the latter may be resolved
into cellulose nitrates, not in six, but in a very great
number of ways. Every molecule may be differently
affected in the process of nitro-substitution. The
character and composition of the resultant product may
vary with strength of acid, its relative quantity in pro-
portion to the cotton taken (this determines the rate
of absorption of water formed during the reaction),

D,g,t,.?<ll„GOOgIl,-

SOLUTIONS OF NITRO-CELLULOSE 75

the temperature at which the reaction takes place, and
the duration of immersion in the acid bath. The
cotton may be nitrated on the surface of the fibre or
nitrated wholly throughout ; it may represent a mix-
ture of soluble and insoluble nitrates or it may possess
a uniform degree of nitration ; and it may exhibit
variations (for the same chemical composition) in its
solubilities in standard solvents; for the successive
polyphase molecules are differently constituted and
differently placed, and doubtless afford progressively-
varying resistances to the effect of the acid bath.

It will be remembered that the theoretical limiting
of nitration (14. 14 per cent, nitrogen) was not obtained
by Eder. Probably the ultimate substitution of nitryl
for every atom of replaceable hydrogen is a limit that
may not be attained in practice. Doubtless some of
the molecules do represent complete replacement,
while others are considerably removed from complete
transformation. It will be shown hereafter that by
colloidization the molecular amplitude of the nitro-
cellulose is reduced to a mean, but such is not the
case for the fibrous material.

Hydration. — When, in the attempt to nitrate cellu-
lose, the strength of the acid mixture is reduced below
a certain figure, a remarkable phenomenon may be ob-
served — instead of a nitration there may be produced a
hydration. We may, therefore, assume that from the
same point of weakness in the molecule there may de-
velop either a nitro-substitution (nitration), or else an
atomic rearrangement accompanied by an absorption of
water (hydration). It has already been stated that ni-

D,g,t,.?<i I,, Google

76 SMOJCELESS POWDER

tration starts, in accordance with our theory, in nitro^ub-
stitution in the water radicles, producing nitro-celluloses
soluble in the alcohol (basic) solution. The hydration,
then, should start in the rearrangement of the parts of
the molecule adjacent to these water radicles. The
quantity of water that is to be absorbed or, rather,
taken up into the substance of the molecule, may, as
shown by Cross and Bevan in their references to mer-
cerizatton, approach the limit C„H„0„.2H,0; corre-
sponding to C„H„0„.2NaOH ; while the definite hy-
drate, C„H„0„.H,0, containing half as much water,
and corresponding to C„HnOi.-NaOH, is readily iso-
lated. Wc have, therefore, as definite limits, the in-
corporation into the molecule of cellulose, C„H„0,, ,
of water in the two ratios, 2H,0 and H,0.

'/ O \ I
Now the radicle C< >C pius H,0 becomes

|\hh/|

H— C— O— H H— 0— C— H ; and as the water radicle

I I

occurs twice in the doubie molecule C„H„0„ ,we have
for the full transformation,

I I

H— C— O— H H— O— C— H

1^ o I

B— C— O— H H— O— C— H

I I + H,0 =

H— C— 0— H H— 0— C— H

I ~° I

H— C— O— H H— O— C— H

I I

D,g,t,.?db, Google

SOLUTIONS OP NITRO-CBLLVLOSE

I I

H— C— a— H H— O— C— H

I I

H— C— O— H H— O— C— H

I I

H— C— O— H H— 0— C— H

I I :

H— C— O— H H— O— C— H

l~ ° I

H— C— O— H H— O— C— H

I I

H— C— O— H H— O— C— H

I I

H— C— O— H H— O— C— H

1 "-I

H— C-O— H H-0— C— H
I I

I I

H--C— 0— H H— O— C— H

I I

H— C— O— H H— O— C— H

I I

H— C— O— H H— 0— C— H

I I

H— C— 0— H H— O— C— H

I I

H— C— O— H H— O— C— H

H— C— O— H H— O— C— H
I I

n,9,N..db, Google

78 SMOKBLBSS POWDER

In considering these forms of modification of the
molecular structure it bhould be remembered that the
molecules of the original fibre are characterized by
their variations in amplitude. And we know, actually,
that hydration represents a breaking down of the cell-
fibre. This breaking down is also illustrated in the
two diagrams of the modified molecules just presented.
In the former it will be observed that but one of the
two water-bonds remains ; in the latter, that both
water radicles have disappeared and that the two
halves of the molecule appear wholly separated.

The effect of hydration in breaking down the fibrous
structure of the cotton and ultimately putting it into
solution may therefore be explained by the following
steps :

I , — The fibre exists as an a^regation of cells of vaiy-
ing amplitude. The solvent at first attacks those cells
that are either the weakest or most exposed, and trans-

I / <
forms in them some of the water radicles, C^

into the hydroxyl forms, H— C— O— H H— O— C— H.

The result is a partial transformation into C„H„0„*-
H.0 = (C„H„0„).

2. — As hydration proceeds, the attack takes place
throughout all molecules irrespective of amplitude un-
til in each molecule one-half of the water radicles are
transformed into hydroxyl forms, and a material, yet
fibrous, built up of modified cells of varying ampli-
tude in each of which one-half of the water radicles

D,g,t,.?<i I,, Google

SOLUTIONS OF NlTXO-CELtVLOSE 79

are transformed into hydroxy! forms, results. This is
the true hydrocellulose, C„H„0„. H,0, or, more prop-
erly, C„H^O„.

3. — As hydration proceeds, transformation advances
towards the total conversion of all the water radicles
into hydroxyl radicles. This is accompanied by dis-
integration of the fibre and a tendency to enter into
solution. The formula shows that with total trans-
formation of the water radicles into hydroxyl forms
the molecule splits up into two halves, between which
there is no chemical union; therefore actual chemical
combination of the two halves ceases, and there can be
no chemical connection between them except such as
may be represented by electrolytic strain.

4. — As solution becomes actually effected, the fourth
and last, and perhaps the greatest, change in the series
occurs. By their intimate contact and admixture the
dissolved molecules, freed from their organic form of
aggregation, are reduced to a common amplitude.
They hereafter constitute amorphous cellulose, and
may be represented as an aggregate of the form
«C,H„0,. It is probable, however, that the number
of atomic particles in each molecule still remains ex>
ceedingly great, as progressive nitration still appears
to occur for this material.

5. — The transformation of thewhole substance of the
cellulose into the form corresponding to C|,H„0„. 2 H,0
represents the dividing line between the chemical and
the physical aspects of the absorption of water into
the substance of the molecule. Any greater absorption
of water than that corresponding to C„H„0„.2H,0

D,g,t,.?<l I,, Google

80 SAfOJCELESS POWDER

pertains to simple solution; any less absorption, to
chemical change, affecting the structure of the cellulose
cell.

6. — The hydrocellulose obtained by the usual pro-
cesses represents, simultaneously, a combination of
all the above-described processes. Part of the cellu-
lose remains wholly unattacked, and, if allowed to
exist, renders the whole mass what the workmen style
"woolly"; part is converted into C„H„0„, a true
hydrocellulose, which, inasmuch as its fibre still ex-
ists, combines to exercise the same effect upon the
physical constitution of the mass as the unnitrated
portion ; part is precipitated as wholly hydrated cellu-
lose of the form C„H„0„.2H,0, and part goes into so-
lution.

7. — Once the fibrous structure is lost by solution,
and the molecules reduced to a common amplitude,
the organic constitution is gone and may not be re-
covered in any way. The cellulose thereafter remains
as an amorphous body. This condition finds a parallel
in the ultimate state of colloided nitro-cellulose, when
the last traces of solvent are totally expelled there-
from, and there results a pulverulent amorphous mass.

D,g,t,.?<i I,, Google

APPENDIX I

RESEARCHES UPON THE NITRATION OF COTTON
By M. ViBiLLB

Very different formulae have been suggested to
represent the composition of the nitro-products de-
rived from celluloses, and particularly the composi-
tion of products of maximum and minimum nitration.
These products were, moreover, obtained by processes
differing at the same time both as to temperature of
reaction, concentration of acids, and the nature of the
sulpho-nitrtc mixtures employed. Therefore the re-
sults were not susceptible of any general interpreta-
tion.

We have thought it well to take up this study
again in a methodical manner, and to investigate the
influence of different methods of nitration and of
temperature upon resultant products.

I. FIRST METHOD OF NITRATION*
Conditions of dipping, — We first decided to deter-
mine the law in accordance with which the degree of

* In translating this paper I have converted the chemical for*
mulx employed therein into those of the syitem employed in the
United States (O = i6).

D,g,t,.?<l I,, Google

82 SirOXELESS POWBER

nitration and physical qualities vary under well-de-
fined conditions of dipping, namely, dipping in pure
nitric acid of various degrees of concentration and at
a temperature of il" C.

The nitration was effected by immersing wadded
cotton in from loo to 150 times its weight of acid;
all elevation of temperature was thus obviated and
the strength of acidity of the bath could be regarded
as constant during the whole of the dipping.

The operations were conducted in large-mouthed,
stoppered flasks of about 500 c.c. capacity and cooled
externally by a current of water. The flasks con-
tained about 250 c.c. of nitric acid. Three grams of
well-carded cotton were introduced into the upper part
of the vessel which was then corked and shaken four
or Ave times, whereby the cotton was equally dis-
tributed throughout the interior, so that each fibre
might be considered as surrounded by 150 times its
weight of acid.

Percentage of nitration. — The content of nitrogen
in the nitrated product was determined by M. Schloes-
sing's method for estimating nitrogen in nitrates. In
order to apply this method to the determination of
nitrogen in explosives, it had to undergo some modi-
fications in detail, which show at the same time the de-
gree of exactness realized in the conditions we have
adopted. The following table presents a resum£ of
the reults of our experiments :

D,g,t,.?<i I,, Google

THE NITRATIOK OF COTTON

1

1"
If

il-i

lil

1

& n «

III

Sis'"

si.
S-aS-

ill
ft

■=3
1:
il

ill

■3

is

sis.

Hi

*.2

Is

1

1

■s-s
Jsl

S>s-|

ml

m

lllll

fit

ill
1-1
1=1

III
III

H

<fl

H

u

H

OS

."s^d

:6J

-a*

iilo

\%

i.^%

^i

JSi*

tat

\

!?l's

— ,-"

nA

1

q

0. °.

<^-o

° °.

'^j^.

1

X:

£; S

XX

I ; I

XS: X

£.

s s

r^E?

s a

£^ 1

\

ri ei

+ ■

+ +

++

+ +

++ +

+

i-

0, d

do

,

dd d

0.

z- z

zz

z = z

zz- z

Z'

s

s 3:

KB

X B

XX X

s

^ ^

:!

III

If

!!!

!!!!

II

«•;

D,g,t,.?<i I,, Google

84 SMOKEI^SS POWDER

The number of cubic centimetres indicated in the
third column corresponds, for each degree of concen-
tration of the acid taken, to the maximum nitration.

Determination of the maximum nitration. — This
maximum was determined in each case by the analy-
sis of specimens exposed to times of dipping of in-
creasing lengths. The limit is, moreover, very clearly
indicated by employing a solution of iodine in iodide
of potassium, which produces a black or greenish dis-
coloration of nitro-products containing traces of non-
attacked cotton. We may state that, beyond the
point where the discoloration ceases to be produced,
prolongation of dipping does not increase the degree
of nitration.

Thus a specimen dipped in acid of density 1.488
gave at the end of 24 hours of dipping 161 c.c, and
was discolored by iodine. At the end of 70 hours it
gave 165.7 c.c, without discoloration.

On the other hand, a specimen dipped in acid of
density 1.490 ceased to be discolored by iodine after
a dipping of 24 hours and gave 183.7 c.c. At the
end of 128 hours the same specimen gave 183.8 c.c.

Nature of the reactions ; speed of reactions. — The
durations of dipping which determine maximum nitra-
tion vary considerably with the degree of concentra-
tion of the acid. The rapid action for the density of
1.500 (at the most from two to three hours) becomes
gradually slower, and requires for the density of I.4S3
as much as 120 hours. The corresponding nitro-prod-
ucts practically preserve the appearance of the original
cotton, but for a density of about 1.470 the action is

D,g,t,.?<l I,, Google

THE NITRATION OF COTTON 85

completely modified, the cotton swells and dissolves
almost instantly, transforming the acid into a clear,
transparent collodion. If this syrupy mass is poured
into running water small white flocks are obtained,
opaque and brittle after drying, and which preserve
nothing of the primitive flbre of the cotton. In these
conditions the limit of nitration is rapidly reached.
Acid of density 1.469 gives after 5 minutes, 134.7 c.c. ;
after 30 minutes, 140.5 c.c. ; after 20 hours, 139.3 c.c.

When the density of the acid falls below 1.46, solu-
tion does not occur; the action becomes much slower
and the cotton appears unattacked, but it is shown
upon washing that the fibres become very friable. A
specimen was collected in the form of a paste. At
the same time the yields decrease very considerably
below the theoretical figure, which indicates that the
cotton has been partially attacked.

For densities below 1.450 it is no longer possible to
isolate, however long the dipping, a product that is
not blackened by iodine. The cotton is slowly trans-
formed into products non-precipitable by water; e.g.,
at the end of 1 5 days there is obtained by treatment
■ in water a very small residue which is intensely colored
black or blue by iodine, and which is of a very feeble
nitration.

Discontinuitiesinthe progress of nitration. — The pre-
ceding table shows that, under the above-mentioned
conditions of dipping, the degree of nitration of the
cotton increases more or less gradually, in accordance
with the concentration of the nitric acid, from 108 c.c.
to about 12S c.c. ; the degree of nitration then rises

D,g,t,.?<ii„Google

86

SMOKELESS POWDER

to 140 C.C., corresponding to a very small' variation
in the strength of the acid, and it remains at this fig-
ure while the concentration of the acid increases to a
very notable extent. It again rises under similar
conditions to 165 cc, then to about 180 c.c, and
then increases gradually to the limits of nitration of
gun-cotton properly so-called.

90 1.47D l.iao

The above diagram, obtained by expressing the
density of the acid by abscissx and the corresponding
percentage of nitration by ordinates, illustrates the
character of the progress of the reaction.

The existence of these discontinuities is of great
importance in relation to the establishment of the
chemical formulae of the nitro-derivatives of celluloses.
It has therefore been deemed useful to reproduce

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON 87

these different degrees of nitration under entirely dif-
ercnt conditions, employing sulpho-nitric mixtures.

II. SECOND METHOD OF NITRATION

We employed sulpho-nitric mixtures formed of
ordinary sulphuric acid (density 1.832) and ordinary
nitric acid (density 1.316). The conditions of dipping
were identical with those which have already been
described; 3 grams of wadded cotton in 250 c.c. of
the mixture. The temperature varied from 19° C.
to 21° C.

The following tabic presents a resume of our exper-
iments. The first column shows the proportion by
volume of nitric acid to sulphuric acid taken :

sSfS.

No. of c col no,

of-heNkr.^?

MdVi»rii>.,'

Chwacter of Specimen.

3.00

a. so

1.70
1.50

195-9

190. 1

184.6 )

I8S.5

i8a.3 )

Cotton not attacked. Soluble in
acetic ether and in ether-al-
cohol

1.40

I.JO

164.0)

166.7^
166.0)

The cotton is very ilightly at-
tacked (a little stringy). Sol-
uble in acetic ether and gen-
erally becomes gelatinous by
the action of ether-alcohol

\Z

,41.^)
"43. S f

Rendered gelatinou* by acetic
ether. Is only swelled up by
ether-alcohol

0.9s
0.90

1333 i
133-7 J

Friable products

D,g,t,.?<i I,, Google

88

SMOKELESS POWDER

These results give rise to various observations.

The sharp advances in the degree of nitration indi-
cated in the first method are equally to be observed
under the second, and practically for the same con-
tents of nitrogen, corresponding to a yield of 1 30 c.c. ,
140 c.c, 165 cc, and 180 c.c. of nitrc^en dioxide,
approximately.

Thus the degree of nitration remains the same for
proportions of sulphuric acid of 3, 1.70, and 1.50; and
lowers abruptly by 18 c.c. for the proportion of 1.40.
Nitration remains stationary for the proportions of
1.40, 1.30, and 1.20, and lowers again abruptly for
the proportions i.io and i.oo.

In order to follow this phenomenon more closely we
undertook dippings with proportions of acid interme-
diary between those for which the abrupt changes had
been observed.

The specimens thus obtained gave the following
results :

A =. ..J.«.

HckOfccolKO,
BTolTcd from 1 Km.

u d* C. and T*>

"-4S

171. 1

Cotton not attacked. Soluble io
ether-alcohol

LIS

IS30

Cotton attacked tlightlr

The percentage of nitration is interpolated exactly
between those indicated above. These trials confirm
the preceding experiments, which show that the exact-
ness of the mixtures under the conditions of our ex-

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON 89

pcriments may be relied upon and that the discontin-
uities indicated do not arise from accidental conditions.
They show, moreover, that there are not, properly
speaking, sharp advances in nitration; and that there
exists a very restricted zone of acid mixtures with
which one may obtain intermediate nitration. But
there exists, nevertheless, a discontinuity in the prog-
rcss of the reaction; and the following diagram,
obtained by expressing the percentages of sulphuric
acid in a mixture, as abscissic, and the yield of nitro-
gen in C.C., as ordinates, allow us to keep track of the
progress of the reaction :

/

/'

1

/

J

I.

1

It appears rational to admit that definite products
correspond to the periods of constant nitration, and
that the mixture of the two products only occurs in
the intervals of transition.

D,g,t,.?<i I,, Google

90 SMOKELESS POWDER

The properties of the cellulose nitrates obtained by
the second process, in respect to solvents such as
acetic ether and ether-alcohol, are, for a given degree
of nitration, identical with those of the nitro-cellulose
obtained by dippings in pure nitric acid. The prop-
erties of cellulose nitrates appear then connected with
their chemical composition, and are independent of
the method of preparation.

We have been able to establish this fact in a more
rigorous manner by nitro-celluloses capable of conver-
sion into collodion<:.

The zone of collodions, according to our experi-
ments, is narrow. It comprises celluloses the nitrogen
content of which is comprised between 180 c.c. and
190 c.c, approximately.

A little above this limit however, up to 195 c.c,
and a little below, to 166 c.c. and often to 150 c.c,
celluloses occur which are transformed into jellies by
the action of ether-alcohol, and which filter by press-
ure through cloth. But it has been found that these
substances do not produce fluid and limpid collodions
useful in the arts; and on drying, collodions of low
nitration have been found to yield an opaque and
brittle film.

Now, all the nitro-celluloses capable of producing
collodions, obtained from widely different sources, and
which we have had occasion to examine, are capable,
in accordance with their composition^, of being arranged
in the method that our experience has made clear to
us. This is shown in the following table :

*..

r:,9,N..<ib, Google

THE NITRATION OF COTTON QI

Collodion -cotton, Rousseau process, 183.2 c.c.

" " Billault-BiUaudot 183.8 "

High-temperature cotton Rousseau, istlot 184.0 "

" " " " 2d " 189.0 "

Swedish gun-cotton for the manufacture of

gelatin-dynamite I93'0 "

Swedish soluble cotton made at Vonges,

in accordance with the directions in the

aide-memoire de la marine 185.4 "

III. HIGHER LIMIT OF DEGREE OF NITRATION
The higher limit of the degree of nitration does not
appear in the preceding tables, which do not present
results relating to a density of nitric acid higher than
1.502. Greater densities are difficult to obtain and,
moreover, our first trials with an acid of 1.516 strength
at a temperature of 15° C. resulted in a very marked
attack upon the cotton. It is probable that dipping
in acids of so great a concentration would only give
good results at lower temperatures, but the upper limit
of nitration of gun-cotton may be obtained indirectly
by the use of sulpho-nitric mixtures. These mixtures,
which were employed for the preparation of gun-cot-
ton for military uses, produce products yielding from
208 c.c. to 212 c.c. of nitrogen dioxide per gram.

By proceeding with special care, we have been able
at a temperature of ll" C. to exceed these limits and
to obtain a product of 215 c.c. This limit remains
exactly the same whatever the proportions of nitric or
sulphuric acid employed, even when Nordhausen sul-
phuric acid is substituted for the monohydrate,

D,g,t,.?<i I,, Google

92

SMOKELESS FQWDEP

The influence of a great excess of sulphuric acid
affects exclusively the rapidity of the process of nitra-
tion, which is thereby considerably diminished.

IV. CELLULOSE INCOMPLETELY NITRATED

The preceding results related to celluloses of maxi-
mum nitration, and the iodine reaction above indicated
permits us to regard the latter as homogeneous bodies ;
but it is possible, by stopping the reaction arbitrarily,
to obtain an idefinite number of celluloses of the
same degree of nitration and of variable properties —
mixtures of different nitro-celluloses and unattacked
cotton.

Among these products we have made a special study
of those which were furnished by the sulpho-nitric
mixtures. On increasing the proportion of sulphuric
acid in the mixture we may so slow down the reaction
as to obtain for a given duration of dipping, say
IS minutes, any degree of mean nitration desired.
The following table shows the composition of speci-
mens submitted during variable times to the actions
of different acid mixtures :

Vol. ofNitroBMDLoiide

HNO,

H,SO,

Ader I, nKn.

After 1 hour*

I volume
I volume

I volume

3 volumes
3i volumes

5 volumes

150. s

i:i

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON 93

All specimens which have been exposed to only fif-
teen minutes of dipping are blackened more or less
strongly by iodine, which indicates the presence of
variable quantities of non-attacked cotton; the second
column of the table appears to show that the excess of
sulphuric acid only affects the speed of the reaction,
and that all products tend toward the same limit of
nitration.

Moreover, we may verify the fact that from the very
beginning of the reaction the products obtained are of
maximum nitration, and that the results of rapid dip-
ping in concentrated acids are simply mixtures of non-
attacked cotton and products of the highest nitration.

Thus the sample which yields 126. 8 c.c. treated in
acetic ether loses 59.44 percent, of its weight, and the
residue presents all the characteristics of almost pure
cotton ; combustion, and coloration by iodine (black
coloration very feeble in the presence of ferrous
salts and hydrochloric acid). Only 60 per cent.,
then, of cotton is nitrated in this specimen; and if we
compare the total volume of nitrogen dioxide, 126.8
c.c, with that of the cotton nitrated, we obtain
2 14.7 c.c. ; which is the number that we would have
found if the reaction were allowed to proceed to com-
pletion.

This method of dipping preserves the cotton fibre
intact, which may be of importance in relation to the
manufacture of nitro hunting powders, for it produces
a natural and absolutely intimate mixture of gun-cot-
ton and ordinary cotton. Moreover, the nitrated
material obtained in this mixture does not differ at all

D,g,t,.?<i I,, Google

94 SMOKELESS POWDER

from ordinary gun-cotton, and wc may hope that it
possesses a stability equal to that of the latter.

V. RESUME AND CONCLUSIONS

Composition and formula of nitro-ctllulose. — The
first degree of complete nitration which the above-indt-
cated reactions allow us to determine corresponds to
a yield of io8 c.c. of nitrogen dioxide per gram, ap-
proximately. This reaction is produced with pure
nitric acid and three equivalents of water. It is slow,
and only gives a small yield, on account of the cotton
being attacked under the hydrating influence of the
acid, which is then the principal phenomenon.

As the concentration of the acids is increased, the
per cent, of nitration appears to advance progressively
to 128 c.c. ; at least this is what the nitrogen content
of specimens 12 and 13 of the first series (page 83)
would appear to show.

It would be well, however, to maintain a certain
reserve upon this point, because since these products
are insoluble in the solvents, the iodine reaction re-
mains as the only index of complete nitration; and it
is to be feared that certain traces of incompletely
nitrated products lower the percentage of mean nitra-
tion.

From 12S c.c. the percentage of nitration rises by
marked increases to 140 c.c, then to 165 c.c, and
finally to 180 C.c. Then, as the concentration of
acid increases, the percentage of nitration rises pro-
gressively, by insensible degrees, to the limit corre-
sponding to military gun-cotton, which yields 215 c.c.

D,g,t,.?<i I,, Google

TUB friTRATlON OP COTTON 95

In this last period, although there is no brisk change
in the percentage of nitration, we may note the very
clear transition point at 190 c.c. and 19S c.c, corre-
sponding to the limit of the zone of the collodions.

In order to account completely for the different
changes by the production of nitro-products corre-
sponding to definite formulae, it is necessary to quad-
ruple the equivalent of cellulose. The nitro-cellu loses
which this formula leads to correspond to the theo-
retical yields of nitrogen dioxide per gram of material
indicated in the following table, and with which we
compare the percentages of limiting nitration ob-
served, corresponding to the discontinuities of which
we have spoken already, or else to a change in physi-
cal properties :

Theory ^^•
CMH„0„<NO,)i,..Ce[luloieeiHl*eaiiiirate.> l»MC.

ChH„0„(NO^„. CellMliM deoDiiraw... f ">"«""»-■■■ ^ ^^ ..

C„H„O,^N0,),...C.IluloKocl0iiltniK...i"^™°" ■■■lI,8'*
CHH,,Olg(NO■),...CelluloMtlcpUllttnle.. \ I >fa "
Ci,H„0|i(NO|)g...Cel[ulOTC hexanltnite , . VFiiabli cDnoDi-j 146 "

ci4H„0„(NO,)4...Celluli»et«raniirue loS "

It will be seen that these formulae take suitable ac-
count of the production of limits of nitration and of
all particulars presented by the reaction.

The approximate results obtained, however, are
always lower than the exact volumes of nitrogen by
about -f-^. The differences appear to be attributable
to the presence of a very small quantity of products
of lower nitration.

Properties of nitro-cellulases. — The explosive prop-
erties of nitro-celluloses are in direct relation to the

D,g,t,.?<i I,, Google

96 Sa/OKELESS POWDEK

percentages of nitration. As the nitration diminishes
the vivacity of combustion in open air decreases, and
the production of carbonaceous residue becomes more
marked. We may thus classify at a glance nitrated
celluloses in one of three groups — gun-cottons, collo-
dions, or friable cottons. The measurements of pres-
sures developed by these different products in a closed
chamber show that the force similarly diminishes with
the percentage of nitration. Thus a collodion>cotton
yielding 1 84 c.c. produces pressures inferior by J to the
pressure furnished by Moulin- Blanc gun-cotton afford-
ing 211 c.c. The percentage of nitrogen constitutes
a true measure of the explosive qualities of a product.^

Finally, we may mention that the stability of nitro-
celluloses decreases with the percentage of nitration,
with respect to reagents such as hydrochloric acid
and ferrous salts. For products of low nitration the
reaction commences when cold ; for those of mean
nitration a few moments' heating is required, but for
celluloses yielding more than 200 c.c. of nitrogen
dioxide per gram, the attack commences only after
sustained ebullition. These products appear then to
acquire the maximum of stability along with the maxi-
mum of power.

Paris, September, 18S3.

D,g,t,.?<i I,, Google

APPENDIX II

PYROCOLLODION SMOKELESS POWDER

By Professor D. UBNDBLiBP

(Translated from the Russian by Lieutenant John B. Bernadon

U. S. Kavy)

The very favorable results obtained with pyro-
cotlodion, and its adaptability to arms of all calibres,
depend upon its composition and properties, which,
for purposes of illustration, may be compared with
those of other materials employed as smokeless pow-
ders.

As to its chemical composition, pyrocollodion may
be designated homogeneous,* and herein consists one of
its most important qualities. All previous and pres-
ent forms of powder did not have or do not have this
property to the degree here implied. From their
very method of preparation, black and brown powders

* Homogeneity, In its full chemical significance, is not claimed.
Inasmuch as the composition of cellulose itself remains a matter
of doubt. The quality Is urged from the technical standpoint. In
relation to the properties of other smokeless powders. It is pos-
sible that a solvent may be found capable of teparating pyro-
collodion fractionally; but pyrocollodion insoluble Id ether or
alcohol, but soluble in a mixture of these substances, is far more
homogeneous than other forms of nltro-cellulose or any of the
Ditro-glycerin powders, inasmuch as the latter are readily capable
of fractional subdivision.

97

D,g,t,.?<i I,, Google

98 SMOKELESS POWDER

are coarse mechanical mixtures, for which any consid-
eration of homogeneity is out of the question. The
same is true for those smokeless powders containing
ammonium nitrate, picrates, etc. Nitro-glycerin
powders may be regarded as gelatinous solutions of
nitro-cellulose in nitro-glycerin, which, from their
composition, are, chemically, non -homogeneous; more-
over, various solvents (alcohol, ether, acetone, etc.)
dissolve certain constituents out of them, leaving
others.

The same may be said of present-day types of nitro-
cellulose powders; alcohol dissolves out of them the
nttro-celluloses of lower nitration ; a mixture of ether
and alcohol, the collodions, leaving the excess of
highly nitrated cellulose undissolved. Pyrocollo-
dion,* however, surrenders no part of its substance to
alcohol, while it is wholly soluble in a mixture of
ether and alcohol. This chemical homogeneity of
pyrocollodion, taken in the sense in which it is stated
to be employed, plays an important r61e in its com-
bustion ; for there are many reasons for believing that
in the case of the combustion of those physically but
not chemically homogeneous substances, such as the
nitro-glycerin powders (ballistite, cordite, etc.), the
nitro-glycerin portion is decomposed first, and the
nitro-cellulose portion bums subsequently, in a differ-
ent layer of the powdeKf It is to be added that the

"Under the aESumption that the remaindet of the solvent is
wholly expelled from the powder.

f The evperimenls of Messrs. I. M. and P. M. Tcheltsov at the
Scientific and Technical La boralorj show that for a given density

D,g,t,.?<i I,, Google

PYROCOLLODION SMOKELESS POWDER 99

homogeneity of pyrocollodion possesses a direct bear-
ing upon the uniformity of ballistic results developed
by its use.

Besides chemical homogeneity, pyrocellulose and
the powders prepared therefrom possess a second dis-
tinguishing quality, viz., that for a given weight of
their substance they develop a maximum volume of
evolved gases, the latter being measured at a given
temperature and pressure. This new conception in-
volves certain intricacies and complexities, and may be
discussed to some degree of fulness, in what relates to
nature and volume of gases evolved upon the decom-
position of powder.

According to the law of Avogadro-G^rard, * the
chemical equivalents or quantities of matter expressed
by simultaneous chemical formulae (e.g., H,0 = i8,
water; CO = 28, carbonic oxide; CO, = 44, carbonic
acid; N, = 28, nitrogen) occupy at a given temper-
ture and pressure a volume equal to that occupied by
two parts by weight of hydrogen, H, =• 2 (its molecu-
lar equivalent). Consequently, if we possess the full
chemical equation of combustion of a substance or

of loading, Ihe composition of che gases evolved by nit ro .glycerin
powders varies according to the surface area of the grains (i.e.,
the thiclcness of strips or cords), a phenomeiion not to be ob-
served iri the combustion of pyrocollodion powder. There is
only one explanation for this, viz., that the nitro -glycerin, which
possesses the higher rate of combustion (Berthelot), is decom-
posed sooner than the nilro-cellulose dissolved in It. This is the
reason why the nilro-glycerin powders destroy the inner surfaces
of gun-chambers with snch rapidity.

'The development of this law is given in " Principles of Chem-
istry," by D. Hendel£ef, 6th ed., 1E95, chap. 7.

D,g,t,.?<i I,, Google

lOO SMOKELESS POWDER

mixture of substances, of which the products are
gases or vapor, it is easy to calculate the volume
occupied by these products at a given temperature
and pressure. For example : the combustion of black
powder may be expressed typically by the equation :

2KN0,+ S + 3C =K,S + 3CO. + N,.
Mol. wt, a X loi +32 + 3 X 12 = 110 + 3X44+28=370.
Volume in form of gases, 3X2 + 2 = 8.

That is, for 270 parts by weight of powder ingredients
8 volumes of gas* are formed, or 29.6 volumes per
* If the weights of the equivalents be expressed \a grains we
may ascertain the volume of gas evolved in litres, when the pres-
sure /'{in millimeters of the mercurial column) and the temper-
ature / (in degrees Celsius) are known. Thus as two equivalent
weights of hydrogen and the equivalent of each gas occupy at a.
temperature f — o and a pressure P= 760 mm. a volume of 31^
litres, then for / and P this volume becomes

32K1 + 0.00367 oij.

Consequently on/ ^volume, expressed in grams, occupies, approx-
imately,

n.l +0.4070^ litres,
t
where/ corresponds to the number of atmospheres, each of 760

p
mm.alo C; i.e.,/ = -^. Thus, in our esample, if / = aooo'C.and

/ = 2500 atm. , the 8 volumes of gas produced by the combustion
of Z70 grams of powder occupy an actual volume of
8. "-■+o.°407-aooo ^ 0.^96 litre.

At o*C. and a pressure of i atmosphere we attain a volume of SS.S
litres for 270 grams. In this manner it is easy to proceed to the
value Vma given in the text, the actual volume of evolved gases
per kilogram of powder.

D,g,t,.?<i I,, Google

PYROCOLLODION SMOKELESS POWDER lOI

lOOO parts by weight of explosive. Brown powder
(cocoa) represents (in its greater progressiveness of
combustion and in certain other respects) a partial
transformation from black to smokeless powders, and
is characterized by the partial carbonization of its
charcoal (which contains much hydrogen and approx-
imates to a composition C,H,0), and by the small
quantity of sulphur entering into its composition. Its
mode of combustion may be expressed approximately
as follows:

6KNO,+2C.H.O=3K.CO.+7CO +4H.O+3N,
6X ioi-i-2 X 80 = 3X138+7X28+4X18+3X28=766.
Volume of gases, 7X2 +4X2 +3X2 =28.

Or as follows :

4KNO,+CjH,0+S=K^O,+K,CO,+4CO+2H,0+3N„
Mol. wt. = 516, Volume of gases = 16,

It is evident, then, that the gas volume correspond-
ing to brown powder is nearly 34, — greater than that
for black powder; whence originates the preference
generally accorded to brown powder over black.

In a similar manner we have for the compete
(typical) combustion of nitro-glycerin,

4C.H.N.O. = 12CO, + roH.O + 6N. + O,.
Mol.wt., 4 X 217 = 12 X 44+ ro X 18 + 6X28+32 = 908
Volume of gases = 12 X 2 + 10 X 2 +6X2 +j =58.

v»» = 63.9-

If we present in the same manner the decomposi-
tion of a type of nitro- cellulose of high nitration, such

?<i I,, Google

I02 SMOKELESS POWDER

as Abel's trinitro-cellulose, C,Hi(NO,),0„ we obtain
the following:

aC.H.N.O,, = 3CO, +9CO +7H.O + 3N,.

Mol. wt., a X 297 = 3 X 44+9 X 28+7X18+3X28=594.

Volume of gases = 3X2 +9X2+7X2 +3X2 =44.

V»„ = 74.1.

If the typical combustion of this nitro-cellulose be
presented by the equation

2C,H,N,0„ = loCO, + zCO + 7H, + 3N,,
that is, if we assume that water is not formed, and
that the oxygen combines wholly with the carbon,
then the F„„ remains unchanged, as the volume of
gas formed (22 X 2 = 44) remains as before. Therefore
we need not stop to consider how the oxygen is dis-
tributed between the carbon and hydrogen in the
products of combustion, as the value of V^,„ does not
vary.*

If, for nitro-cellulose of high nitration we substitute
Eder's pentanitro-cellulose, C„H,j(NO,),0,„ which

''II is anolher matter if a portion of the oxygeo continues in
combination with the nitrogen, or if the oxygen proves insuffi-
cient to convert a.11 the ca.rbon a.nd hydrogen into gases; that if,
if hydrocarbons are formed; but this becomes a case of incom-
plete combustion. Such conditions have a certain bearing upon
the combustion at smokeless powders, especially when the sol-
vent is not completely expelled; but, on Ihe one hand, the quan-
tity of hydrocarbons formed is relatively small, and on the other,
they are formed (as also compounds of carbon and nitrogen, as
cyanogen), in relatively small quantities, for all powders, even
when the latter contain an excess of oxygen. In considering
type forms of combustion there is no need of investigating second-
ary conditions of this class, especially as by so doing we ar«
divened from the direct study of the general problem.

D,g,t,.?<l I,, Google

PYSOCOLLODION SMOKELESS POWDER lOJ

corresponds to a content of 12,75 pc cent, nitrogen,
and to the composition of ordinary nitro-ccUulose
employed for smokeless powders, we obtain a greater
evolution of gas, for

2C„H,.N.0„ = CO, + 23CO + isH.O + SN,.
MoLwt, 3X549 = 44+ 23 X 28 + 15 X 18+ 5X28=: 1098,
Volume of gases = 2 + 13.2 + 15.2 +5,2 = 88.

r,.„ = 80.1.
The increase in volume of gas hereby realized is due to
the fact that the quantity of carbonic acid evolved is
diminished, while that of carbonic oxide is increased,
which causes an increase of total gas volume, since,
for the equation

c + o, = co., K,» = 4S-S;

and for the equation

C + O =C0, f'„.. = 7l.4.
If we descend to a lower nitration and consider
Eder's tetranitro-cellulose, C„H„(NO,),0,„ we have
no longer the case of complete combustion; for 20
equivalents of oxygen are required to convert 12 of
carbon and 16 of hydrogen into gaseous products and
vapors, while there are but 18 of oxygen available, un-
less we assume the products of combustion as CO,
H,0, and H,.* It is known, however, that in the case
*Iii the latter case (without formation of carbon) the decompo-
sition would be:

C„H,.N.O„= 12CO +6H,0 I- 2H, +aN..
Mol, wt., 504='2Xa8 + 6Xi6 + aX2 + 2 XjaS = S04.
Volume of gases = I3X3 +6X3 +3X2 + 3Xa =44-
r,,., = 87.S-
But typical combustion, according to such an equation, is prac-
tically impossible; carbon and hydrocarbons are formed, and tti«

-\GotK^Ie

I04 SMOKELESS POiVDEli

of combustion of carbohydrates low in oxygen, the
latter combines with the hydrogen, from its greater
affinity for that substance, leaving a part of the carbon
deposited in an uncombined state. Consequently, such
conditions do not correspond to complete combustion.

The formation of CO, shows that there is a certain
excess of oxygen in pentanitro-cellulose ; whereas
typical combustion, corresponding to maximum gas
volume, requires all carbon to be converted into car-
bonic oxide. Such typical combustion is afforded by
pyrocollodion, the composition of which corresponds
to the formula C„H„N„0„, as is shown by the follow-
ing equation ;

5C.H„0, + 12HNO, = C..H,.(NO,),.0,. + i2H,0.

CeUulDu Nitric Acid Prrocellulou Water

combustion that actually does occur is intermediate in character
to that expressed b; the above and by the two following equa-

aCi.Hi.NiO,, = C* + aoCO + i6H,0 + 4N,.

3Ci,H,.N,0„ = aaCO + 14H,0 + C,H, + 4N,.
For the first, V,,,, = 79.4; for the second, 81.4; the mean of
the two latter is S0.41 of all three, 8a-4. This quantity is close to
that afforded by pentanitro-cellulose and pyrocollodion. In this
manner may be explained the phenomenon that upon the combus-
tion of nitro-cellulose containing a little less than ia.5 per cent.
nitrogen, or of pyrocollodion containing a certain quantity of un-
evaporaied solvent (which is equivalent to a lowering of nitni'
tlon), results are obtained that approximate to those produced by
pyrocollodion powder, although velocities and pressures are
somewhat lowered. The existence of this phenomenon depends
upon the homogeneity of the powder; whence it follows that it Is
better to have a content of a little less than la.s per cent, nitrogen
with a homogeneous powder than a content of above la. 5 per cent,
with the powder non-homogeneous, and that the best results are
developed by homogeiteous pyrocollodion of nitration N = 13.4
per cent.

r:,9,N..<ib, Google

FYROCOLLODION SMOKELESS I'OiVDER 10$

In typical combustion it corresponds to the follow-
ing equation :

C„H,.N„0„= 30CO + i9H,0+6N,
Mol. wt., 1350 =30X28+19X18 + 6 X a8= 1350,
Volume of gases =30X2+19X2+6X2 =110.
'^,... = 81.5.
Before proceeding further, we desire to call atten-
tion to the fact that, whereas for bro,wn powder we
realize a volume of 34 approximately, we have here a
volume of 81.5, whence, judging from volumes of
evolved gases, pyrocollodlon should prove 2\ times
more powerful than brown powder. Actual experi-
ments show that the powders stand in about this rela-
tion to one another. In units of energy per unit for
weight of explosive we have

Pjrocollodiea Brown lUtio

powder powder

47 m.m. R. F. about 220 81.5 2.7:1

9-in. gun, " 223 90,7 2.5 : r

i2-in) gun, " 210 93 2.3:1

From this it is evident that our computed value of
V^„^ is in complete accordance with actual experimental
results.

In this manner we may consider it as proven that,
for a given temperature and pressure, pyrocollodlon
develops a greater volume of gases (and vapor) than is
developed by black or brown powder (for which
V^„, = 30), and even greater than is afforded hy pow-
ders prepared from the more highly nitrated forms of
nitro-cellulose, and by the nitro-glycerin poivders*

•The rapid, simple and novel method of comparing the force of
explosives herein employed was first suggested and used by me

D,g,t,.?<i I,, Google

I06 SMOKELESS POWDER

In order to establish the full significance of the
above deduction, it remains to show (i) that from the
standpoint of practical applicability we can foresee no
other material capable of developing as great a value
for F„„ as pyrocollodion ; (2) that the physico-chem-
ical and ballistic qualities necessary in a smokeless
powder are- developed by pyrocollodion, not in a less,
but in an equal or greater degree than by other mate-
rials employed as smokeless powders; (3) that the
estimate of ballistic efficiency of a smokeless explosive,
through consideration of its volume of evolved gas,
without regard to conditions of temperature, leads us

in 1892. It was developed through comparison of the composition
of sraolceless ponders and of tiieir products of cotnbustion and of
ihi; results of esperi mental firings made at the laboratory. Al-
though I see clearly that not only the volumes of products of
combustion, but also their temperatures, must be taken into

decomposition of smokeless powders, nevertheless I purposet]^
give preference in these investigations lo phenomena relating to
volumes of gases evolved, not only on account of the simplicity
of the latter and their direct accordance with ballistic results, bitt
for the reason that with present methods for estimating tempera-
tures developed by explosives {and these methods are unreliable)
it becomes necessary to make numerous arbitrary assumptions
(especially in relation to specific heats of gases and vapors at high
temperatures); while for volume calculations we have definiteness
of composition as a starting point; and if there be any assump-
tion to be made, it relates to the distribution of the oitygen be-
tween Che carbon end hydrogen, which, from the chemical stand-
point, is not so material— and so far as It relates to volume it
is of little significance. In all cases, however, I present but the
elementary comparisons of performances of powders, as the fuller
treatment of the subject docs not constitute the object of mjr

D,g,t,.?<i I,, Google

PYKOCOLLODIOl^ SMOKELESS POWDER 107

into no error, although it would at first appear that
temperature would have a direct effect upon the prac-
tical qualities of a powder.

Since smokeless powder was discovered, so many
schemes were set afloat for meeting general demands,
that up to the present time there remain as open
questions which form of smokeless powder is the
superior, and whether new and still more efficient forms
may not be looked for in the future. In order to re-
ply to these inquiries, it will be necessary first to glance
over the compositions of materials capable of conver-
sion into smokeless powders under the following as-
sumptions: (i) That they leave no solid residue after
combustion, and that their gases exercise no injurious
effect upon the metal of guns; {2) that they undergo
no change upon keeping for long periods of time, and
contain no volatile ingredients; and (3) that they may
be readily prepared in quantities sufficiently abundant
for practical needs.

There are but few elements capable of producing
gases that do not act upon metals, and, generally
speaking, it is useless to try to find others besides
hydrogen and nitrogen, and their compounds with
oxygen and carbon, that do not act upon gun-cham-
bers at the temperatures of combustion of powder.
Therefore, in general terms, the composition of those
mixtures or compounds suitable for conversion into
powder may be expressed as

C,H„N,0..

The energy imparted to the projectile is derived from

D,g,t,.?<i I,, Google

I08 SMOX'£LESS FOWDER

the conversion of the mass of the powder into gases,*
the transformation being accompanied with the pro-
duction of great heat. These fundaniental conditions
serve to limit the number of materials that are capable
of conversion into smokeless powder, the limitations
arising not only from the above-named practical re-
quirements, but also from the chemical impossibility of
existence of many bodies which, if obtainable, would
decompose in the manner requisite for efficient ballis-
tic action. Thus, e.g., there does not exist, nor can
we look forward to the existence of, such a polymer
(in the solid or liquid form) of hydrogen as H, , which
would decompose into hydrogen, H, , with a corre-
sponding production of heat.f

If we may not look for explosives among the sim-
plest chemical combinations of the elements, we may
perhaps find them among those compounds of nitro-
gen and hydrogen which stand in the same relation to
ammonia, NH„ as the hydrocarbons do to methane,

• And is not derived from an external source of energy, suchai
the tension of a spring or the physical compression of gases, ai
in theGiffard gun.

f If such a substance existed, then its decomposition, according
to the equation H). = »Hi, would afford a weight sn for a volume
in; that is, Pioi>irould be equal to looo, the greatest possible
value. For nitrogen under similar conditions we would have
fitot = 71.4, T less than for pyrocollodion. But the existence
of such a polymer is highly improbable. If argon (vid. Mende-
Ifief, " Principles of Chemistry," 6th ed., 1895, p. 745) were the poly-
mer of nitrogen, Ni. its conversion into nitrogen could only be
accomplished through the absorption of heal; i.e.. it would find no
place in (he category of " explosive " bodies (towbich oione pos-
sesses a relation).

D,g,t,.?<i I,, Google

PVROCOLLODIO!^ SMOKELESS POWDER IO9

CH,. We should thus have, corresponding to ammo-
nia, the series N«H,^, (e.g., diamidc N,Hj; triamide
N,H,; etc.) and the series N,H„ N.H, _,. etc. As
the representative of the latter we have, for w = 3, the
nitro-hydric acid of Curtius, N,H, which actually is a
very explosive body, and which forms salts, e.g., with
ammonium N,(NHJ=: N^H„ which is also explosive,
decomposing into the gases nitrogen and hydrogen
with the evolution of heat, although ammonia itself is
not susceptible of explosive decomposition, but ab-
sorbs heat in the reaction. If such compounds could
be easily prepared, and if they possessed the qualities
necessary to an efficient smokeless powder, such as
non-volatility, good keeping quality, progressiveness
in combustion, etc., they would prove especially suit-
able for conversion into smokeless powders, as the
corresponding values of f',,,, would be greater than
for other powders. Thus we should have for nitro-
hydric acid,

2N.H = H,+ 3N,.

Mol, wt. 2X43= 2 4- 3x28 =86.

Volume of gases, 2 -f- 3X 2 = 8.
f^..« = 93-0.

For N,H. the volume would be still greater, as
J^.M = '33-3- But even if such products could be con-
veniently prepared from readily procurable materials it
would be useless to consider them as available for
conversion into smokeless powders, for the reason
that they do not decompose through gradual or
progressive combustion, which is indispensable in a

D,g,t,.?<i I,, Google

110 SAfOHTELESS POfVDEX

smokeless powder, but detonate or decompose with
extreme suddenness; hence, while they might prove
suitable for filling mines or shells, they are unadapted
for use in cannon. This property of progressive com-
bustion or decomposition in successive strata is pos-
sessed only by those substances containing both com-
bustible ingredients, and ingredients capable of effect-
ing progressive combustion, such as carbon and
hydrogen, which are consumed by the oxygen held in
close proximity to them but which is not in direct
combination with them.

The "combustion" of a powder is the union of
the carbon and hydrogen of the mixture or com-
pound with the oxygen that it contains, and with
which it is in association, but not in direct combina-
tion. From what has been said already, it is evident
that if the powder is to be smokeless and produce the
maximum volume of gas, V,„t, it must evolve no
other gases than carbonic oxide, CO, water vapor,
H,0, and nitrogen, N,. If hydrogen be evolved, with-
out the formation of the corresponding quantity
(equal volume) of carbonic acid, free carbon may re-
sult, i.e., the powder will not be wholly smokeless on
account of insufficiency of oxygen. If the combus-
tion, as indicated by the equation, reveals carbonic
acid or free oxygen {without the corresponding vol-
ume of hydrogen), an excess of oxygen is evident,
and f"|,„ will not possess its maximum value.

We have, therefore, in the case of a composition or
mixture C„H,„N^O„ the maximum volume V^,„ for
typical smokeless combustion, corresponding to two

D,g,t,.?<i I,, Google

PYROCOLLODIOl^ SMOKELESS POWDER Itl

conditions: (i) When the content of oxygen, r, is
just sufficient to convert the carbon into CO, and
the hydrogen into H,0, i.e.,when r ■=n-\-m; (2)
when the content of hydrogen is relatively great, as
f^i,,, for H,0 equals lii.i, i.e., more than for nitro-
gen and for carbonic oxide, for which V^„, = -ijgi
= 71.4. Moreover, all substances of the composition
C«H,.N,0,+« will develop volumes between 71,4 and
II I.I, if the decomposition products be CO, N, and
H,0 alone, as is required for rendering y,„, a maxi-
mum. Our problem becomes, therefore, the com-
parative examination of those bodies rich in hydrogen,
for which V„„ may be greater than for pyrocellulose
{81.5). We must ask: Are there not known sub-
stances, or mixtures of substances, rich in hydrogen
suitable for smokeless powder? To answer this query,
let us examine various definite compounds and mix-
tures.

Among the carbon compounds a large content of
hydrogen is characteristic of methane (marsh gas),
CH,; also among the nitrogen compounds, or the
ammonium derivatives.

Hydrocarbons of the limiting (saturated) series
C«H„+,* form nitro-compounds, and may, therefore,
produce explosives. To methane itself, CH,, there
correspond mononitro-methane, CH,(NO,); dinitro-
methane, CH,(NO,),; trinitro-methane or nitroform,
CH(NO,)„ and tetranitro-methane C(NO,)*. These

•See "The Principles of Chemistry, " by D. Mendeltet, 1B91,
Longmans, Green & Co., London, Vol. I, p. J44. J. B. B.

D,g,t,.?<i I,, Google

112 SMOKELESS POWDER

substances are volatile as well as explosive, but all
represent a deficiency or an excess of oxygen. As
shown by V. Meyer and Professor Zalinski, the ex-
plosive properties of mononitro-methane are espe-
cially great when it is combined with potassium or
sodium to form the metallic salts, CH.KNO, and
CH,NaNO„ which represent, so to speak, first homo-
logues of the salts of nitric acid, since CH,NaNO,
— NaNO, equals the homoI(^ous difference CH,. "
Experiment shows that this substance belongs to
the category of detonating explosives, and Is, there-
fore, unsuitable for use in guns (but suitable for
mines).

If the decomposition proceeds without formation of
free carbon (although there be but little oxygen), it
should be as follows :

2CH.NO, = 2CO + 2H,0 -f H, + N..

If it be thus, then F,„, = 98.3, which is very great.
But, as has been said, the substance is unfit for use in
guns on account of its tendency to detonate. Be-
sides, like other nitro-methanes, it is volatile, and for
this reason is further unadapted.

The little known, but doubtlessly explosive, dinitro-
methane contains an evident excess of oxygen, devel-
oping on combustion, CO, + H,0 -^- 40, + N„ which
corresponds to the relatively small volume V„„ = 66.
It is evident that the excess of nitrogen and of oxygen
combined with it in the NO,, according to the known
principle, does not increase but rather diminishes
Vxm' '^^^ same is true for nitroform, CH(NOJ, =

D,g,t,.6<i I,, Google

PYROCOtLODlON SMOKELESS POWDER 11$

CHN,0„* and for tetranitro-methane, the discovery
of which is due to the skill of our eminent savant,
L. N. Shishkov. Bottf of these substances contain too
much oxygen to develop maximum gas volumes. A
large value of F,,,, would be characteristic of mixtures
of products of nitration and of hydration (substituting
the water radicle for hydrogen, — H +0H) derived
from methane, as :

4CH,NO, + CH.N,0, = sCO + ;H,0 + jN.-f
Mol. wt., 4x61 + 106=5 X28+7X 18+3X28 = 350.
Volume of gases, 5X2+7X2+3X3 =30.

V^ = ^%-
Or:

NiLnr-melhuie Hcthft alcohol

4CH,N0,+CH.0 = sCO +8H.0+ 2N..
Mol. wt., 4 X 77+32 = s X28+8X 18+2x28 = 340.
Volume of gases = 5 X 2 +8x2 +2x2 =30.
K,« = 88.2, etc.

But such mixtures, -although possible from the chem-
ical standpoint, are unsuitable for use as powder, be-
cause their constituents are in part volatile; and this,
apart from the consideration that liquid explosives are
prone to detonation, which is more to be dreaded than
formation of smoke, as detonation destroys the guns.

* As the typical decomposition of nllroform, we have — •

4CHN.O. =4C0, +7O. +aH,0 + 6N,.
Mol. wt,, 4 X iSi =4 X44 + 7.X3a-i-aXi8 + 6xa8:=6o4.
Volume of gases 4 X 2 +7X3 +3X2 +6Xa =38.
f The mixture 7CH, + 3C{NO,), presents such a composition,
etc., but such mixtures are all as practically unsuitable for pow-
der at mixtures of mono- and djaitro-methane.

D,g,t,.?<l I,, Google

114 SMOKELESS POWDES

Among the closely allied derivatives of methane as
a hydrocarbon rich in hydrogen, the development of
a lai^e gas volume may be looked for from substances
presenting the composition CN.H.O,. Such a com-
position is possessed, for example, by the mixture
of a molecule of formic aldehyde, CH,0 (or of one
of its numerous polymers), with ammonium nitrate,
NH.NO,, or the hydroxyl derivative of methylamine
(i.e., CH.NH, in the form CH,[OH]NH,) in com-
bination with nitric acid, HNO,, The typical de-
composition of such a compound, if realized, would be
expressed by the equation :

CN.H.O, = CO + 3 H.O + N,.
Mol. wt., no = 28 + 3 X 18-1-28 = no.

Volume of gases = 2 +3X2 + 2 = 10.
V„, = 9.09.

But such a compound either cannot be produced, or
else is obtained only with great difficulty ; or, as a mix-
ture of ammonium nitrate with the polymers of formic
aldehyde (e.g., glucose, C,H„0, = 6CH,0), it develops
undesirable qualities, such as hygroscopicity, a charac-
teristic of all mixtures containing ammonium nitrate,
and is therefore unsuited for use as smokeless powder.

Hence, after searching through all the possible com-
binations of the simplest derivatives of methane, we
are unable to find among them (as also among sub-
stances containing no carbon) any suitable for employ-
ment in practice as smokeless powder, although we
find compounds developing larger volumes of gas than
pyrocollodion, and which may prove suitable for use

D,g,t,.?<i I,, Google

PYROCOLLODION SMOKELESS POWDER 115

If we turn from substances containing one atom of
carbon to those with two, three, etc., atoms to the
molecule, we shall find, other conditions being the
same, smaller values of V,t„, the volume decreasing
the farther the Umit is departed from, as is illustrated
in the following table of possible, little volatile, com-
pound ethers of nitric acid* and their hypothetical
nitro-compounds, corresponding to the series of alco-
hols, C.H„{NO,)..

3C,H,(N0.), + 2C.H.O, r,...= ^ iooo=86.a

C,H.(NO,). " =-^1000=84.3

C,H.(NO.). + 4C.H,(N0,)(N0.), " =tS»t 1000=83.7
C.H„(NO.), + 4C,H.(N0,),{N0,), " =TVifir 1000=82.7

etc., etc.

The possible, yet up to the present, hypothetical,
nitric ethers of nitro-glucol, although capable of devel-
oping large values of F",^, and adaptable on account
of their non- volatility, possess no advantages over
derivatives of the higher alcohols, such as glycerin
and mannite, materials that are readily obtainable
as they are widely disseminated throughout nature.
Wc shall therefore fix our attention upon the latter,
first, as they present in their analogues substances ex-
tremely rich in hydrogen, capable of producing large
values of l^,„„; and second, because they are easily re-

* Considered by themselves these ethers of diatomic limitiaK
(saturated) alcohols C,H,,(KO,), consume into CO and H.O onlji
for « = 3- For greater values of n there is a deficiency in oxy-
gen; for n =:^ 3, an excess. We have chosen them as an example
on account of their slight volatility, and because they approximate
nitro-glycerin and nitto-mannite in composition.

r:,9,N..<ib, Google

Il6 SMO/irEL£SS POWlfSJl

acted upon by nitric acid, forming the explosive com-
pound ethers, nitro-glycerin, C.H.(NO,), = C.H.N.O, ,
and nitro-mannite, C.H.{NO0,O.= C.H,N.O„. Both of
these nitro-derivatives are easily prepared. The for-
mer was first employed as an explosive by the re-
nowned Russian chemist N. N. Zinin, at the time of
the Crimean war, and subsequently by V. F. Petru-
shevski, in the sixties, before the discovery and very
general employment of Nobel's dynamite and other
nitro-glycerin preparations; the cause of their gen-
eral use being the ease with which the base material —
glycerin — was obtainable in nature, while the reac-
tion with nitric acid (admixed with sulphuric) was
easily effected, i.e., the manufacturing process was a
simple one.

Nitro-manntte, isolated and investigated by N. N.
Sokolov, professor at the Medico-Chirurgical Academy,
is also easily prepared, but not in its lower degrees of
nitration. This circumstance is important, for the
reason that the readily manufactured nitro-glycerin
and nitro-mannite are not themselves available for use
in guns, although very well adapted for detonating
effects. They correspond, moreover, to relatively
small values of Vi„,, as they contain an excess of
oxygen :

C,H.(NO.). affords f.„. = 63.9.
C.H.(NO.). " f^,«. = 61.9.

But as these substances contain an excess of oxygen,
they may be admixed with others containing a defi-
ciency thereof, and which they consume, evolving car-

D,g,t,.?<i I,, Google

PYROCOLLODION SMOKELESS POWDER WJ

bonic oxide and developing relatively large volumes,
V,t„ ; while by admixture with such substances, low in
oxygen, or not containing it; their detonating qualities
may be caused to diminish, or made to vanish, as in
dynamite, by combination with an inert base (tripoli,
magnesia, etc.), whereby the tendency of nitro-glyc-
erin to detonation through shock is diminished. In
this manner, by admixture with a combustible sub-
stance, nitro-glycerin powders are formed. If we take
cordite as an example, we find that on account of
its excess of oxygen it produces a relatively small gas
volume; we may, therefore, select a mixture of nitro-
glycerin and collodion (assumed as C,H,[NO,],0,)
such as ballistite and determine for it V„„ on the as-
sumption that it shall develop only CO, H,0 and N,.

2C,H,N,0,+7C.H.N.O.=48CO +33H,0 + ioN,.
Mol.wt.aX 227+7 X 252=48X28+33X18+10X28=2218.
Volume of gases =48X2 +33X2 +10X3 =i8j.

Therefore, if nitro-glycerin^ powders contain only
the quantity of nitro-glycerin necessary to produce
H,0 and CO, then the volume of gases evolved by
them is almost the same as that developed by pyro-
coUodion. It is evident, then, that neither nitro-
glycerin nor its mixtures, when employed as smoke-
less powder, evolve volumes of gases greater than pyro-
coUodion, and that admixture with other substances,
of whatever kind they may be, although homogeneous
from the mechanical standpoint, are still far less homo-
geneous than any single substance, and that it is use-

r:,9,N..<ib,G00gle

Il8 SifOKElESS POWDER

less to seek (or nitro-glycerin powders capable of ex-
ceeding pyrocoUodion powders in point of magnitude
of V^„, I apart from other considerations. This ap-
plies also to nitro-mannite, the source of preparation
of which is far less common than glycerin, and to
many of the hydrocarbons analogous thereto, as glu-
cose, starch, cellulose, etc. If all of the six atoms of
carbon in mannite are in the same combination as in
the limiting (saturated) alcohols:

C.H,.0.=

CH,(OH)CH(OH)CH(OH)CH{OH)CH{OH)CH,{OH),

then in glucose, C,H„0,, one atom of carbon should
be combined as in aldehyde,

C.H„0.=

COH CH(OH)CH(OH)CH(OH)CH(OH)CH.(OH),

and, therefore, if mannite represents a hexanitrated
product (compound ether as derived from an alco-
hol), glucose represents only a pentanitrate. Mate-
rials such as cellulose, starch, and the like, of compo-
sition C,H„0,, may be regarded as the preceding alco-
hols — anhydrous, arranged as follows with reference
to the di-alcoholic groups:

CHCH,
C.H,.0, = COH CH(OH) CH{OH) CH{OH)— v— ,

O

whereby it appears that there are only three com-
plete alcohol groups remaining out of the six in man-
nite. Therefore, iii the latter case, we should expect
to find only trinitrated products, which is actually
what occurs, If such a scheme throws light on the

D,g,t,.?<i I,, Google

PYROCOLLODION SMOKELESS POWDER "9

matter from one standpoint (as relates to the number
of hydroxyl radicles giving rise to nitric ethers), it illu-
minates it obliquely from another, which is of consid-
erable importance to us. In all aldehydes, beginning
with the formic and acetic, a tendency to polymeriza-
tion is to be noted, due, doubtless, to the property
of aldehydes of entering into various combinations
(with H„ 0, NaHSO,, etc.); hence the composi-
tion C,H|,0„ containing an aldehyde grouping,
should also possess this property, so far as relates
thereto. We may, therefore, safely assume that the
molecular composition of cellulose, judging from its
properties, is polymerized, i.e., it is of the form
C„H„,0„, where « is probably very great. If we as-
sume M = 5, the cellulose becomes of composition
C„H„0„, and, for the highest degree of nitration,
C„H„(NO,)„0„. But pyrocellulose has a composi-
tion C„H„(NO,)„0„ ; therefore, the number of inde-
pendent nitro-celluloses {nitric ethers) may be very
lai^e.

This is very important in the conception that the
nitration of cellulose may be carried up to any desired
degree, and for known concentrations a mixture of
nitric and sulphuric acids neither dissolves nor reacts
upon a product of nitration. Again, cellulose is the
most widely disseminated in nature of all the hydro-
carbons possessing the composition C,H„0„ consti-
tuting the tissues of all plants and prepared from time
immemorial in great masses as cotton, flax, paper,
etc., while its products of nitration present an unal-
terable material suitable for conversion into smokeless

D,g,t,.?<i I,, Google

I20 SMOXELESS POWDER

powder. This side of the matter needs no further
elucidation, but it must be remembered that before
the development of pyrocoUodion, it was stated that
the higher the nitration of the cellulose the higher the
explosive produced, and that in manufacturing powder-
from highly explosive nitro-cellulose (of composition
about C„H„[NO,]„0„),collodion{of composition about
C„H„[NO,]„0„) was added, for the reason that higher
nitro-celluloses in the form of filaments or dust were
easily detonated (hence their employment for mines),
while the Tatter property was reduced or caused to dis-
appear after gclatinization, of which collodion was
easily susceptible and for which purpose it was added.
The introduction of pyrocoUodion changed existing
views upon the subject, showing that maximum force
for nitro-cellulose was not to be sought from the high-
est degrees of nitration (i.e., for maximum content of
nitrogen and oxygen), but that it obtained for that
mean degree of nitration present in pyrocoUodion.
For the latter material fi„, = 81.5; while for nitro-
cellulose of maximum nitration, C,N,{NO,),0„ f„„ =
74. 1 . The above represents only one side of the theo-
retical investigation of materials suitable for smoke-
less powder; but other considerations are also in ac-
cord, as will be shown later ; and we have, therefore,
gone considerably into detail, the more ut^ently since
it has i>een necessary to struggle with prejudice,
harmful to success in such a new field as that of
smokeless powders.

Among the possible materials proposed, apart from
mixtures of such different bodies as ammonium nitrate

r:,9,N..<ib, Google

PYROCOLLODION SMOKELESS POWDER 131

and various organic substances (such mixtures were re-
jected in practice), must be considered the nitro-com-
pounds corresponding to benzol and its derivatives,
naphtalin, etc., as coal-tar constitutes an abundant
source for their production in large quantities, and
they are easily nitrated. From the class of the so-
called "aromatic compounds" derived from benzol,
C,H„ it is useless to expect smokeless explosives de-
veloping large volumes of V„„, although many are
high explosives, beginning with Melinite or picric
acid, C,H,(NO,),OH, which constitutes a powerful
material, although far from the best, for torpedoes
and explosive shells; and since some of the first
smokeless powders were mixtures containing picric
acid. The cause of the small gas volumes K„„ devel-
oped by the aromatic compounds is due to their com-
position, as they are all low in hydrogen. This view
may be Illustrated by a few examples.

To benzol there correspond bodies the general com>
position of which may be expressed by the formula
C,H,_a(NOJa. If a equals i, 2 or 3 (these substances
are known and easily obtained), the oxygen content is
insufficient to consume the carbon into CO and the
hydrogen into H,0, although explosion occurs with
the formation of carbon (smoke, soot) and of hydro-
carbons.

Total smokelessness could be realized from mixtures
of highly nitrated products, as:

4C.H,(NO,).+ C,H,(NO,). = 30CO -l-6H,0-|-9N..
Mol. wt., 4X258 + 168 = 30X38-^ 6Xi84-9X38=iaoo.
Volume of gases = 30 X a +6Xa -I-9X3 =90.
f.,..= 75.

r:,9,N..<ib, Google

122 SMOKELESS POWDER

If, instead of such non-existing highly nitrated ben-
zols, pyroxylin be employed (as in the American
smokeless powders of Munroe and other inventors), a
gas volume approaching that developed by pyro-
collodion is realized :

6C.H.NO, + 36C,H,N,0.i =19aC0 -|- 106H,0 + 4aN,.
Mol. wi,, 6 X 133 + 26 X 197 = '9" X aS + 106 x 18+42x38=8460.
Volume of gases = 193 X a + 106 X 3 +43X3 =680.
Fio.t = 80.4-

The matter assumes a different aspect if ammonium
nitrate, NH,NO„ be employed for converting the car-
bon and hydrogen of nitro-benzol into CO and H,0,
This substance contains a large quantity of hydrogen for
a relatively small content of oxygen (but for this re-
sult a large quantity of NH,NO, must enter into the
mixture), and greatly increases the volume of gas
developed, as is evident from the following :
3C.H.HO1 -t- i3NH«NO. = laCO + 3iH,0 + 14N..
Mol. wt..3X 133 + 13X80= 12 X 38 + 31 X 18 + 14x38 = 1386,
Volnme of g>s«3 = 13 X 3 +31x3 +i4Xa =114.
r»„=83.7.

But mixtures of this salt must always be avoided if
a satisfactory smokeless powder is to be produced, as
it is soluble in water, as well as hygroscopic, and pro-
duces with viscous, oily materials only coarse mechan-
ical mixtures.

Similar results are to be obtained from other aro-
matic substances, and we may refer by way of ex-
ample to mixtures of pyrojQ^lin with picric acid,
C.H,(NO,).OH, and nitro-naphtalin, C„H,(NO,),
such compounds having been recently experimented

D,g,t,.?<i I,, Google

PYROCOLLODIOlf SMOKELESS POWDER I23

with (but abandoned in practice) as smokeless pow-
ders. Among other disadvantages, they develop
smaller gas volumes, F,„,, than pyrocoUodion, on
account of their relatively small content of hydrogen.

After an examination in the above manner of the
composition and properties of all possible materials
capable of employment as smokeless powders, we
arrive at the following deductions in relation to the
volume of gases (measured at given temperature and
pressure), V^,„, developed by their combustion :

I. — Only substances containing nitrogen, carbon,
hydrogen and oxygen are capable of entire conversion,
as required for smokeless powders, into gases that do
not react upon gun-metals. Hence all other explo-
sive substances (e.g. , fulminate of mercury, chloride of
nitrogen, etc.) containing haloids, metals, phosphorus,
etc., are unsuitable for use in gunpowders.

2. — When the combustion of carbon results in the
formation of carbonic acid gas, CO,, a less volume of
gas is formed than when carbonic oxide, CO, is the
resultant product; and as the former requires more
oxygen than the latter, the increase of oxygen or
nitrogen (if, as is usually the case, the oxygen enters
into combination with the aid of the elements of nitric
acid) is injurious, instead of useful, although there
exists full conversion into gases as is required for
smokeless powder.

3. — ^The greater the quantity of hydrogen in the
powder, other conditions being equal, the greater the
gas volume, F,„„ corresponding to the combustion of
the powder; and, therefore, substances derived from

D,g,t,.?<i I,, Google

124 SMOKELESS POWDER

the limiting (saturated) series of hydrocarbons are
more suitable than bodies of the " aromatic " series
for smokeless powders.

4. — Not any of these explosive materials not contain-
ing carbon (as N,H, NH,NO,)> that evolve large vol-
umes of gas V„„ and decompose upon ignition, are
such as will not detonate, i.e., evolve their gases so
rapidly that they crush the walls of guns ; whence it is
useless to consider them as materials adaptable for
conversion into smokeless powders.

J. — Some of the materials containing but little car-
bon and much hydrogen may prove suitable for use as
powders or powder mixtures, evolving large volumes
of gas upon combustion ; but, so far as known, they
are either volatile, or liable to decompose spontaneously
and detonate, or else they are prepared with difficulty
from mixtures not widely disseminated, so that at
present it is useless to look for materials for smokeless
powder from among them.

6. — Nitro-glycerin itself develops but a small gas
volume (f,„, = 63.9), as it contains an excess of oxy-
gen. It may be employed in mixtures to form smoke-
less powder, and its mixtures with nitro-cellulose, such
as Cordite and Ballistite, which are practically homo-
geneous from a physical standpoint, develop gas
.volumes, f^,„„ a little less than that evolved by pyro-
collodion (although such mixtures erode guns, as
already stated).

7. — Cellulose, C,,H,„0„, is a substance widely dis-
seminated in nature and of general industrial employ-
ment; by its n on -volatility, insolubility, durability)

D,g,t,.?<i I,, Google

FYROCOLLODION SMOKELESS POWDER IZg

etc., and by the readiness with which it is nitrated (as
it contains much hydrogen), it constitutes a superior
base for smokeless powders.

8. — Among all the forms of nitro-cellulose capable of
smokeless combustion, the maximum gas volume, f,„„
corresponds to C„H„N|,0., (= 12.44 pc cent, nitro-
gen), which is pyrocoUodion, for which V,„,^=^ 81.5,
and which is capable of complete gelatinization in a
mixture of ether and alcohol, in which form it is com-
pletely free from any tendency to detonate. In the
first place, it is the most suitable of all the nitro>
celluloses; in the second, it is the most rational and
readily obtainable form of smokeless powder, destined
to supplant not only other smokeless powders, but also
to replace, by reason of its greater homogeneity and
its combination of qualities, other pyroxylin powders.

Pyroxylin powder is a mixture of nitro-celluloses,
of higher nitration, such as C,H,(NO,),0„ and of lower,
as C,H,(NO,),0,; pyrocoUodion is a definite homo-
geneous single form of nitrocellulose. By changing
the proportional relation of contents of the high, or
insoluble, and low, or soluble, nitro-cellulose, it is
evidently possible to make the pyroxylin approach
the pyrocoUodion powders; but (as has been shown
in recent years, especially in cannon- powders) the limit
of improvement of these forms always falls short of
pyrocoUodion. The latter is homogeneous and un-
changeable, while pyroxylin powders vary according
to their composition. However, from its origin it is
in no wise different from the perfected powder of
Vieille (although considerably different from the

D,g,t,.?<i I,, Google

126 SMOKELESS POWDER

original form thereof), presenting instead of a mix-
ture, from the chemical and mechanical standpoint,
a homogeneous limiting mass of the composition
C„H„N„Oj„ which is required in order that the pow-
der may create upon combustion the maximum volume
of vapor and gases. It is certain that henceforth
pyroxylin powder will continue to approximate to
the pyrocollodion until the two become identical. In
brief, pyrocollodion represents the Russian limit of
modification and improvement of the French pyroxy-
lin powders, the development of which marked an
epoch in ordnance progress, but which has not hitherto
presented an invariable and constant relation of the
elements entering into its composition. In this light
pyrocollodion powder may well be styled Franco-
Russian. Begun in France, it has been completed in
Russia.

D,g,t,.?<i I,, Google

APPENDIX III

THE NITRATION OF COTTON
By M. Bbwlev

Within recent years different varieties of nitro-
cellulose which hitherto have possessed only very
restricted uses have had their fields of application
broadened, especially in their relation to the manu-
facture of explosives.

Photographic collodions, celluloid, artificial silk,
etc., have nitro-cellulose for their bases. On the
other hand, besides gun-cotton, employed for military
purposes, as for the chaining of torpedoes and other
similar appliances, nitro-cellulose enters into the com-
position of various kinds of smokeless powders, gum-
dynamites, cartridges for use in presence of fire-damp,
etc.

Each of these applications demands, so to speak, a
special variety of nitro-cellulose, and the government
explosive-factories entrusted with their preparation,
so far as relates to their use as explosives, have been
gradually forced to meet requirements differing widely
as to character.

For a long time the Moulin Blanc factory, which
was established for the production of naval gun-
1*7

D,g,t,.?<i I,, Google

128 SMOJ^ELESS POWDER

cotton, had scarcely more to do than to produce gun-
cotton of maximum nitration for military uses. For
this the well-known mixture of three parts sulphuric
acid by weight of 65.5 Baum^ and one part by weight
of nitric acid of 48 Baum£, has always been employed.

Since then the Moulin Blanc works and those at
Angoulfime, where the manufacture of gun-cotton was
established in 1887, have had to produce other kinds
of nitro-cellulose, which it became necessary to man-
ufacture practically in a regular manner.

The theoretical researches of M. Vieille, described
in his note of September 13, 1883, inserted in Vol. II
of the " Memorial des Poudres et SalpStres " (p. 212
et seq.), classified different varieties of nitro-cellulose
in the manner following, in accordance with the
formulae for their chemical composition :

Vol. ot Nitroaen Dioxide
DbCDcaged pa fp*.ta

Cellulose cndecanitrate 214^

^ I gun-cottons,
decanitrate 203 )

enneanitrate 190 \

octonitrate '7^ > collodions.

heptanitrate 162 )

hexanitrate 146 \

pentanitrate 128 V friable cottons.

tetranitrate 108 )

Gun-cotton, as well as friable cottons, are insoluble
in a mixture of alcohol and sulphuric ether, while
collodions, on the contrary, are soluble in such a
mixture.

Indeed, it is hardly possible to isolate each one of

D,g,t,.?<ll„GOOglC

THE NITRATION OF COTTON 129

these varieties, and one always finds mixtures of two
or more neighboring varieties.

Thus in practice, the products obtained are classed,
not into cellulose endecanitrate, cellulose decanitrate,
etc., but into gun-cotton properly so-called, for which
the content of nitrogen is between 210 and 200 c.c,
into superior and inferior collodions, with nitrogen
content ranging between 190 and 180 c.c. 'for the
former and from 180 to 170 for the latter; .and friable
cottons.

Gun-cotton, properly so-called, is theoretically in-
soluble in ether-alcohol. In reality it always contains
small quantities of less highly nitrated soluble products.
Collodions deposit in this solvent an insoluble residue,
due to the presence of non-attacked cotton, or friable
cottons, or even more highly nitrated cottons.

It is for this reasoi* that solubility in ether-alcohol
is determined the same time that nitration is estimated.

The different soluble collodions are distinguishable
from one another, moreover, by the greater or less
viscosity of the solution obtained. As this property
is one that may possess practical importance in the
employment of collodions, it appears useful to study
it simultaneously with the solubility and the content
of nitrogen.

A series of researches were undertaken at the An-
goulSme powder-works for the purpose of determining
the practical method of obtaining a chosen product
from the series of those just enumerated. These
researches do not claim to possess the scientific value
of those made in 1883 by M. Vieille upon the nitra-

r:,9,N..<ib, Google

130 SaiOKBLSSS POarpEK

tion of cotton. The resources at the powder-works
laboratory, especially in relation to personnel, are too
limited to justify the hope of rigorous precision for
results obtained. But apart from their utility as a
guide in the manufacture of a desired product, they
seem to possess a certain interest in relation to the
conditions controlling the nitration of cotton.

I. METHOD OF NITRATION AND MODE OF REPRE-
SENTING RESULTS

M. Vieille in his researches in 1883 had employed
two methods of nitration. In one he used mixtures
containing only nitric acid and water. In the other
he added to these bodies variable proportions of sul-
phuric acid.

The latter method has been alone employed in
practice ; it is the one exclusively used in the trials
that constitute the object of the present work.

Apart from nitrous vapors, which are always present
in appreciable but very feeble quantities, and forcig[n
matters, which are never found in the acids employed
except in negligable quantities, every mixture em-
ployed for dipping cotton for the production of any
one of the various nitro-cellutoses contains the three
following elements : monohydrated sulphuric acid,
H,SO, ; monohydrated nitric acid, HNO,; and water,
H.O.

If we desire to classify the infinite number of mix-
tures that may be obtained from all possible combin-
ations of the three elements, in groups giving rise

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON I3I

finally to products of the same kind, it is necessary to
have recourse to a graphic method of representation of
these mixtures.

In expressing the relations of the proportions of
the two elements to the third, each mixture is de-
fined by only two numbers. It is easy, then, by em-
ploying one of them as an abscissa and the other as
an ordinate, to express by the ordinary system of
rectangular codrdinates any mixture determined by a
single point.

The different mixtures giving rise to the same
product will thus be grouped by zones, and a knowl-
edge of these zones will facilitate the practical obtain-
ing of a desired nitro-cellulose, whether new acids are
employed to produce it or whether spent acids from a
previous manufacture are employed for the purpose.

II. RESULTS OBTAINED BY M. VIEILLE

We shall reconsider, in the order of ideas just in-
dicated, the results obtained by M. VieiUe in 1883,
and mentioned in the preceding note.

In all experiments under the second method, sul-
phuric acid of density 1.832 was employed, corre-
sponding, according to the special tables, to a degree
by areometer of 65.5 Baumd and to a percentage of
water of about 8 ; and, upon the other hand, to nitric
acid of density 1.3 16 which, if it be supposed free from
all traces of. nitrous vapors, should mark 34.6 by the
Baum£ areometer and contain 50^ of water.

Applying these figures to the volumetric propor-

r:,9,N..<ib, Google

SJfOJrELESS POW^DER

tions of each mixture given in the table on page 87,
the following new table is formed :

Per cent, of Ni-

No.erEi-

'"KSlu'"ob! "

H,30,

HNO,

H.O

,

100

13- 1

ai.7

195-9

1

iS-S

34-3

190.1

3

19- S

2i.2

1S4.6

4

aa.9

31-7

IBS-S

5

36.0

34-8

18S.3

Solubility

6

87-8

36. S

164.0

not deter-

7

30.0

38.6

166.7

miited

8

38-4

41.1

166.0

Q

100

35.4

44.1

141.S

39.0

47.6

143-5

II

41.0

49.8

i33-»

11

100

43-3

61.9

133.7

Under the system of representation adopted, by
which the proportions of the two other elements are
expressed as ratios to 100 parts by weight of H,SO,,
the figures of the preceding table may be graphically
expressed as in Fig. i, page 133.

All the points representing the mixtures employed
lie upon the same straight line ab, since they are
formed with the same nitric acid marking 34.6° by the
Baum^ areometer. This line is inclined at 45", since
the acid chosen contains as much water as mono-
hydrated acid ; it starts from the point a correspond-
ing to eight per cent., there being exactly that niuch
water in one hundred parts of the sulphuric acid to
which the one hundred parts of the other components
are expressed as ratios.

Outside of this line there exist an infinite number of
other points corresponding to acid mixtures the action

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON 133

of which upon cotton was not studied by M, Vieille.
By employing nitric acid of increasing strengths succes-
sively, along with sulphuric acid of 65.5° Baumd, mix-
tures will be obtained represented by points upon
the lines ac, ad, etc., which start from the common
point a and are more or less inclined according to the

quantity of water in the acid employed. The practical
limit is the line of corresponding to 48° 6aum£, the
strongest obtainable in current manufacture, and which
contains about lO per cent, water.

These are the regions left aside in previous studies,
the exploration of which is now undertaken from the

D,g,t,.?<i I,, Google

134 SMO/CELBSS POWDER

standpoint of practical results to be obtained industri-
ally from the corresponding acid mixtures.

III. EXPERIMENTS IN NITRATION. (FIRST SERIES)

In this first series of experiments the base material
was the chemically pure absorbent cotton employed in
pharmacy. - The acid mixtures were prepared direct
from the three principal elements, sulphuric acid, nitric
acid and water. For this purpose a carboy of sul-
phuric acid of 65.7° Baum4 was drawn from current
supplies. On the other hand a certain quantity
of nitric acid of the highest possible strength had
been collected at the nitric-acid factory, and from this
nitrous vapors were completely expelled by passing
carbonic-acid gas through it for a number of hours at
a temperature of about 70° C. After expulsion of
fumes this acid marked 47.7° Baum£.

The selected sulphuric and nitric acids were kept in
carboys carefully sealed and provided with a com-
pressed-air emptying system, the air used being care-
fully freed from all traces of moisture. As all the ex-
periments could not be carried on at the same time, it
was necessary to provide that the elements entering
into them should be always identical.

The water present in the acids was that shown by
the special table corresponding to their areometric de-
gree, this quantity being checked by direct analysis,
and was 6.5 per cent, for the sulphuric and 10.5 per
cent, for the nitric acid.

The mixtures employed for the experiments were
determined by adding to the quantities of the two

D,g,t,.?<l I,, Google

THE NITJIATIOM OF COTTON \%%

adds taken the quantity of water necessary to bring
the total weight up to 1.2 kilos. The percentage
compositions were deduced from these weights and
that of the water in the acid components.

Each mixture was divided into three lots of 400
grams each, of which two were employed for dupli-
cate experiments and one was held in reserve.

The 400 grams of mixed acid were introduced into a
large-mouthed flask provided with an air-tight stopper)
and an equilibrium of temperature established ; then
the four grams of absorbent cotton were added and
the flask violently shaken. Under these conditions
nitration took place almost instantaneously, and it
may be said that each fibre of cotton was instantly
surrounded with 100 times its weight of liquid acid.

The flask was then corked and placed under a
stream of water maintained at a constant temperature
of from 18° to ig° C, which was that of dipping, the
cotton remaining the whole time in the acid bath.

Two dippings were made for each mixture studied,
one of them corresponding to reaction double in length
of time to that of the other. The admitted durations
of reaction were six, twelve, and twenty-four hours,
according to the kind of nitro-cellulose that was sup-
posed should be obtained.

It was not considered necessary to study reactions
of longer duration, difficult to realize in practice. In
certain cases it was deemed sufficient to control results
by reconducting the experiment in a bath of the same
composition, and allowing the reaction to continue
for forty-eight and even up to sixty hours.

D,g,t,.?<i I,, Google

I $6 SMOKELESS POWDER

Twenty-five mixtures, corresponding pretty nearly
to the whole region embraced by those obtainable tn
practice, were thus experimented with ; that is to say,
by maintaining as proportions of nitric acid and water
expressed in ratios to one hundred parts of sulphuric
acid by weight, from lo to 60 per cent, of the former
and from 10 to 45 per cent, of the latter.

In fact, for nitric acid below a certain limit, reac-
tions became too slow. On the other hand, from a
standpoint of economy, its proportion cannot be too
much increased on account of its relatively high price.
As to water, its lower limit is fixed by the strength
of the strongest acids obtainable in current manufac-
ture.

The twenty-five mixtures studied represent suffi-
ciently well, then, the region that may be explored in
practice ; they are spaced apart regularly, so that by
the examination of the products obtained, proper ac-
count may be taken of the phenomenon of nitration
throughout the region explored.

The percentage of nitrogen in each of the products
thus obtained was determined by Schloessing's method,
described at the close of M. Vieille's paper above re-
ferred to. Solubility in ether-alcohol and viscosity in
that medium were determined under the methods em-
ployed at the Angoul£me powder-works and described
at the end of the present paper.

The following table presents a resume of all results
obtained from the analysis of specimens produced in
this first series of experiments :

n,<i-^f^:>yG00glc

THE NITRATION OF COTTON \%7

■3

J
1

1

J

a

m

n:;i : i :

1 -S

= = lii i i i

X

5

- S*^- •!,« - S '

•" --r-o-o ««« <T.O.««H un«o.oO '«-««o

«"-"=ss ■>ss»5«,s*|;*"3.-3;-'s-

|4^

i==rs£i i???j&sjgjs5i?rl8

3

s

1'

SSS5S jas « p s

1

It;

s K =iiiisKSsi"i i s

1 i iiSiiiiiiil i i

1

1
J

o.o»«.^«»«o-««-t.fl-t;fl.r.-.n-00--Or-

sssJ'-ffJs-ssssRsiiisig-a-JsJ

sii

8=========,==============

1,1

s

-:i;s>>^=;^><!-:^ss>>^=s«f<^=!s>>

r:,9,N..<ib, Google

138 SMOKELESS POWDER

Inspection of this table shows that mixtures in
which the percentage of nitric acid is low, and no-
tably mixtures V and VI, produce after twelve hours
reaction an incompletely nitrated product. Even
after twenty-four hours the nitration is not com-
'plete; a fact verified by certain complementary ex-
periments for these latter. They will be discarded,
then, as out of the category of practical mixtures.

The graphic representation of the other mixtures,
by the method above indicated, is reproduced below
(Fig. 2). By the side of each point representing one of
them, the corresponding number is indicated in Ro-
man numerals; and the principal qualities of the prod-
uct taken from the preceding table are expressed in
ordinary figures, the figures chosen for each reaction
being those corresponding to the longest duration of
reaction. The first number is the percentage of ni-
trogen; the second, the solubility; the third, when
given, the viscosity.

If, as indicated at the beginning of this article, the
products be divided into gun-cottons, collodions and
triable cottons, overlooking certain small quantities
of accompanying products that may be mingled with
them, it will be seen that mixtures giving rise to
products of the same kind may be grouped in quite
distinct zones. The lines which limit these zones are
nearly parallel to one another. They depart a little
from the straight line and are slightly inclined to the
co-ordinate axes; percentages of nitrogen and solu-
bilities alone have served for tracing them. Vis-
cosities, which refer to collodions only, are pre-

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON 139

sented only as indicators, and are far from being the
same for all products in a given zone.

to

.

\ XVI

£f

*0-^ S8.8

»».«/

"

1

/ / ""^

7

f w

/

11 / /xvii J

■ni/xv

Bfl!o / hai'-sxivi

4^/ 167JI

• S.1 / / MJi iwJ Mjy BM

I «

/

/ /^B aS? 7

It

u

L

1

5

fa!

/ °

b s 1 Si

1 S XXI

41 J R

1 g ao.B* a
1 IV sxin

fsijsi M

Ifll

hi ^w "p™

ii

^i *f?/

•S w*/

•/

/ ' 7 */

1 XXV /

§ 10

1 ■ m&

E

\

&

\

PROPORTKIH OF WATER TO 100 PARTS OF SULPHURIC ACID (MONOHVDRATE)

Without being able to discover, in results obtained
for these viscosities, the expression of any well-de-
fined law, it may be remarked, however, that they are

D,g,t,.?<i I,, Google

I40 SMOKELESS POWDER

in general greater, according as the corresponding
percentages of nitrogen themselves are greater. Thus
it is to be remarked that the mean viscosity for the
zone of lower collodions is 65', while for the higher
collodions the mean attains 140".

IV. EXPERIMENTS IN NITRATION. (SECOND SERIES)

The preceding results were obtained, as indicated,
with pure wadded cotton. In general this is not the
base materia! employed, but spinning waste, bleached
and freed from grease, which costs less. The fibres
of the cotton are more or less twisted and entangled,
and, notwithstanding the effects of carding, there
always remain at the time of dipping small agglom-
erations, into which the acid penetrates with diffi-
culty. In order to estimate the influence of the base
material employed upon results obtained, a second
series of trials were undertaken under conditions
similar to those of the first series, except that the
refuse cotton from current manufacture was substi-
tuted for the absorbent wadding. During this series
of experiments the temperature was maintained dur-
ing the whole time of the dipping at about from 7° to
8° C, The acid mixtures were prepared as indicated
above. The sulphuric acid employed marked 65.8°
Baume, and contained only 5 per cent, of water.
The nitric acid, freed from nitrous vapors, marked
47.1° Baume and contained 15 percent, of water. The
per cent, composition of each of the twenty-five mix-

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON I4»

tures employed was calculated on the basis of these
figures, and verified for a certain number of cases by
direct analysis. As above stated, 4 grams of cotton
were immersed in 400 grams of acid. The absorp-
tion of the cotton by the liquid proceeded as rapidly
as with the wadding.

The table on page 142 presents the results ob-
tained in the second series of experiments.

More clearly than in the preceding series, it is to
be remarked that for a certain number of mixtures,
especially for those in which the relative proportion
of nitric acid is low, prolongation of the reaction in-
creases the percentage of nitration. We shall dis-
card mixtures V and VI as heretofore, since the re-
action, to be complete, would have to be prolonged
too far.

Figure 3 (page 143) represents graphically the
results of the second series of experiments.

As in the preceding series, different mixtures, pro-
ducing products of the same kind are grouped in
zones, and these zones are sensibly of the same form
as those of Fig. 2; still again, but this time perhaps
a little less clearly, however, the viscosity of the col-
lodions appears to increase with the percentage of
nitration.

V. EXPERIMENTS IN NITRATION. (THIRD SERIES)

A third series of dippings was finally undertaken,
the conditions of which were practically identical
with those obtaining in practice. Bleached English

D,g,t,.?<i I,, Google

SMOKELESS POWDER

1

X

7

1 J
1

i|j

-~ii. ^ i

\

1=1^

=1*1 i i

%

8

1^

J S E RS J- 5

I

IP

s'^-"8i;i= sijjis-siJsPi-^il

2

1

"

>

S 5 J RS R * 1

i,?*

M s. ffiiiiff-is-giJ's s. \

ft^

mf » »d« « .r..t.o« .roce o •* >o

58 1 ss|?»5»5?5H?s t
>

D,g,t,.?<i I,, Google

THE NITRATIOir OF COTTON

Spun-cotton waste from the powder-factory supplies,
was employed as the base material. This was dipped
in different acid mixtures formed, as indicated above,

:s OF SULPHURIC AI

Fig. 3

(MONOHVDRATE)

from distilled water and the sulphuric and nitric acids
of which part had been employed in the preceding
experiments. The proportions for dippings were al-

D,g,t,.?<i I,, Google

144 SMOKELESS POWDER

ways the same; 4 grams of cotton to 400 grams of
mixed acids; but the duration of immersion of the
cotton in the acid bath was reduced to eight minutes.
After such immersion at a constant temperature (12°
to 13° C. approx.) the cotton was removed, drained,
lightly pressed, and placed in an earthenware crock
in which the reaction completed itself, the pot being
placed in a stream of water at the current tempera-
ture.

The results from this third series of experiments
are given in the table on page 145.

These results may be expressed graphically in the
manner shown in Fig. 4, page 146, neglecting mix-
tures V, VI and XXV, which only produced partially
nitrated products.

Still again, the products obtained allow the mix-
tures to be grouped into zones analogous to those
resulting from the two other series of experiments.
In each of these zones viscosities are variable and ap-
pear not to follow a well-defined law, although high
viscosities accompany the highest percentages of
nitrogen.

VI. VARIOUS EXPERIMENTS

The experiments of which a resume has just been
given exhibit the influence of acid mixtures upon the
products obtained. Here, indeed, lies the principal
element entering into the whole manufacture of nitro-
cellulose. But other, secondary causes may equally
influence final results, and it has appeared useful to

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON MS

■3

■s

■1
%

I

1

3

1.
1

,. 5 . R

lis

"J5 sxss-i S i S K''

. '=1^

ti^ SSIi'SJS sill?

!

i .
1

1 » !»*» »:i sa s

l|5

si"-s ji= ssJiiJ-isss-i-is js

1*

jtitij^' ?iljjlj^silliliss

i

s

I-

s a Kss ss ss s

1

IP

\
I

Ms

«0«.co«0» «* *<. W.O «0 «o »» •« ^0

IgHsss HScSJs JsS?s?lffl«

E
.1

1

»<..n-0.>.)«c>o,..«>.o<no«>nn.r>~»,«<..-0u3

« S'S SS S S RS ^Rsassssssssss^ s

ll

S!SRis°"'i!i«RJS!;Ksiss«,iS!;si;s

*

8= = - = --= - = ---- = =

1

s s

D,g,t,.?<i I,, Google

146 SMO/CMLESS POWDER

Study them also. Among these causes, duration of
reaction has been briefly touched upon already, as
well as the nature of the base material. To these must

be added temperature during dipping and reaction, as
well as the later effect of the manipulations that ni-
trated cotton may undergo after the operation of

D,g,t,.?<i I,, Google

THE NITRATION OP COTTON I47

dipping. These different effects will be examined
successively.

Base materials. — Cotton wadding nitrates more
readily than spun-cotton waste, which nitrates with
the greater difficulty the more it is tangled, the
coarser its threads, and the more knots it con-
tains. On the other hand, it equally appears that the
previous preparation of the waste destined for dip-
ping exercises a very sensible influence upon the vis-
cosity of the collodions obtained. Thus it is that two
cottons of absolutely different origin, submitted un-
der identical conditions to the action of a commoa
acid mixture, produce collodions possessing the same
mean percentage of nitrogen, but with viscosities
varying from what they ordinarily are to double this.

Duration of reaction. — The appended table, in
which two or three durations of reaction correspond
to each mixture, shows that for a same final product,
the reaction should be the more prolonged the lower
the proportion of nitric acid in the mixture.

Some experiments were made to follow more
closely the progress of the reaction; a resume of them
is presented in the following table. These experi-
ments refer to three acid mixtures from the first
series, the numbers of which are recalled in reference
to results obtained; the conditions of dipping and re-
action are those of this series; the temperature of
the reaction was about 20' C. approximately:

D,g,t,.?<i I,, Google

SMOKELESS POWDER

Mixtur

eXUI

Miilu

eXVl

Mi«u

eXXI

Rweiioo

^■rro^

Solubility

S^S",

Solubility

NiifMrn

"K""

I hour

165.8

91.7

186.8

94.9

306. 4

3 hours

166.8

95.5

189

95.0

209

4

8.3

93.0

191. 8

96.2

309

6,8

M.8

198

94.1

6.7

166.8

95.4

19.. 8

^.7

110

2

5.6

»4 "

166. 8

98.1

194

96.6

3,0

6

10.6

■ These experiments comprise the three principal
types of nitro-cellulose studied; superior and inferior
collodions and gun-cotton. They show that for the
two former a maximum of nitration is hardly ob-
tained before the end of two hours of reaction; for
gun-cotton, on the other hand, from eight to ten
hours are required. If the reaction be prolonged
beyond these hmits, the solubility has a tendency to
increase. In these experiments viscosity could not
be measured; but the preceding tables seem to show
that no relation exists between it and duration of re-
action.

Temperatures of dipping and reaction. — ^A certain
number of dippings were made under conditions iden-
tical with those of the second series of experiments,
at the three very different temperatures of 1°, 12°
and 25° C. These temperatures were maintained
throughout the whole duration of the reaction.

Results obtahied are grouped in the following
table:

D,g,t,.?<i I,, Google

THE JVITXATION OF COTTON

II

Te

operuurc dutiiiR Dippi

ni and Reaclioa

\l

i*C.

.='C.

.j-c.

II

Nitn.-

Vi».

Nitro-

Vi.-

Nitro-

Vi.-

hn.

K

biiur

ity

S-

bijitr.

itjr

S"

t?

':r

I

6

.90.0

95-9

180

191.8

97-8

104

193. a

97.7

16

in

13

207.8

4.4

205.4

4.4

107.6

1.6

VII

(1

i77-t

»4-9

iBq.o

ga.Q

fKl

193.3

97-7

■Kt

X

6

17B.S

r8^.4

q6.8

7a

.S4.4

96.3

hi

G

ib7.a

78.9

38

172.0

9a.9

3O

172.0

96.1

37

Other experiments were made to the same end
with wadded cotton under the conditions of the first
series. The results were as follows :

•3

Te

mpen

urea

ur

^.

1^

14

I 'S

Vis-
ity

Nitro-

,fS.

S

Via-

IS.

f?

^

XTI

6

181

2 96.S

t86.8

96.7

1893

iBl

2 97-4

95.1

»

94.4

XIII

h

rb7

4 93' 8

Ibq

93-3

171

4

16^

6 90.7

166

i<)»

t

XV

h

8 96.5

43

192

98. r

48

194

9S.I

i«H

8 97.4

17

191

97-0

26

'91

t>

XXI

SOB

8 8.9

308

6

7-1

34

309

8 6.7

209.2

7-0

20S4

These experiments seemed to show that, so far as
collodions were concerned, increase of temperature
during dipping and reaction increases the percentage
of nitrogen and the solubility, but sensibl)^ diminishes

D,g,t,.?<i I,, Google

IJO SifOJfCELESS POWDER

the viscosity. In other words, a low temperature re-
tards the reaction. In what relates to gun-cottons,
the influence manifests itself less distinctly; it is ad-
mitted, however, that at high temperatures the solu-
bility has a tendency to increase.

Subsequent manipulations. — The different cellu-
loses are submitted before use to a number of
manipulations; first to washings, which are necessary
to remove the last traces of acidity, and for certain
ones to pulping, which serves to facilitate subsequent
operations.

Washing is eflfected by a more or less prolonged
boiling^, either in pure water or in an alkaline solu-
tion; the pulping by beating-engines similar to the ap-
paratus employed in the manufacture of paper.

These operations, which are absolutely mechanical,
have no influence upon the chemical composition of
the final product, and therefore upon the percentage
of nitrogen; but it is different for solubility and vis-
cosity, which are purely physical properties.

Experiments were made with the view of ascertain-
ing how various kinds of nitro-celluloses acted during
these operations. Results are grouped in the tables
on page 151.

These various experiments were made with quite
large quantities of gun-cotton, consequently more or
less homogeneous, so that taking of samples should
suffice to explain certain anomalies to be noticed in
the progress of phenomena observed. From the
figures in the preceding tables it may be concluded,
on the one hand, that the two operations of washing

r:,9,N..<ib,G00gle

THE mTRATlON OF COTTON

1 i'

i

X

* u

\

11- ?1^^

1 f

i

■s

1

1"

i

s

1

1' J

^

' te^

%

"

?o"j

f

:

g

1- ffs"*

o

■s

f

•5

I

I*

«

^

■S

t

o

s

°

1. SSffE

1

£.
3

g ^

-

O

1

1

l-

^

i

a

\

l?S

i

i ?^-s

.«

a.

1

E

1

B,

t

a.

t.

«>

i. 5^5 Jff

1 s"

a

n

1

-K

"

z

J

?

ifi

-m

1

1

t

M:

I

X

i

>

1^

T

".

§ s

"

1

r

"

1

J

^fe

1

i

1- ^sJ?

I 1'

■"

1

:f

2

"s : : : :

1 l^s

i

k

i

^ -

i-.„>l

r:,9,N..<ib, Google

IS2 SMOKELESS POWDER

in warm water and pulping have the effect of increas-
ing the solubiHty of gun-cottoits ; on the other hand,
that these two operations diminish to a marked de-
gree the viscosity of the collodions.

VII. RESUME AND CONCLUSIOMS

■As already stated, the results of the experiments
just described complete in a certain sense those ob-
tained by M. Vieille in 1883, since they relate to a
series of mixtures that had not been studied up to
this time.

Apart from the theoretical interest they may pos-
sess, they also possess a practical utility.

When it is desired to produce a certain definite
nitro-cellulose, the first thing to determine upon is
the composition of the dipping mixture to be em-
ployed. Heretofore, the proportions of the different
elements, whether new or spent acids, were calcu-
lated somewhat arbitrarily. The experiments, of
which a resume has just been given, permit a more
methodical procedure in such a case.

These are only laboratory experiments, it is true;
and in practice a thousand causes, more or less well
understood, arise to influence final results. Some
supplementary experiments have been made to as-
certain how these known causes tend; but it would
be rash to assert that it would be possible, on the
strength of the data afforded by these experiments,
to obtain with certainty a product of which all the
qualities were predetermined.

D,g,t,.?<i I,, Google

TME NITRATION OF COTTON 153

However, the great similarity of the results ob-
tained in the three series of experiments, each of
which approaches more nearly than the preceding
to conditions obtaining in practice, justifies the be-
lief that, although no one of them may enable us to
calculate the proportions of a mixture capable of pro-
ducing a certain product, nevertheless, the general
trend of the phenomenon of nitration is that indi-
cated by the position and relative importance of the
different zones above referred to.

The knowledge of this progress in the phenomenon
of nitration permits us, then, after a preliminary trial,
which, besides, is not undertaken by chance, to -
modify, if necessary, the proportions of the mixture
first taken, in such a way as to arrive at a desired end.

Different considerations serve as guides in the
preparation of the preliminary mixture. While still
keeping within the zone corresponding to the prod-
uct desired, the relative proportions of nitric acid
and water may be varied between quite wide limits.
It is desirable, from the standpoint of economy, to
diminish the quantity of the most expensive element;
that is to say, the nitric acid; in certain cases, how-
ever, to develop certain qualities in the final product,
we may be led to increase it. Finally, if spent acids
of known composition are to be employed, one mix-
ture may be found more advantageous than another,
according to the relative quantities of acids to be
taken.

The acids used, nitric acid or spent acids, always
contain nitrous vapors to a small extent. These

r:,9,N..<ib,G00gle

IS4 SMOKELESS POWDER

nitrous vapors may, if present in sensible quantity,
falsify conditions upon which it was thought reliance
could be placed, and this fact must be borne in mind
in calculating the trial mixture. But in practice the
proportion does not exceed from i to 2 per cent., and
within these limits it may be admitted that the pres-
ence of nitrous vapors does not change results sen-
sibly.

It is necessary, besides, to bear in mind that on ac-
count of the reaction that takes place in the dipping-
vats, and which produces water, the proportions of
sulphuric acid, nitric acid and water in the vats are
no longer the same as those of the original mixture.
These alone are the conditions which affect the de-
gree of nitration and are determined beforehand ac-
cording to the considerations just indicated. The
others, which must also be known, since they serve
in preparing the mixtures properly so-called, are
easily deduced by means of corrections, which de-
pend upon the size of the vats, the relative weight of
cotton employed each time, etc., etc.; and they are
determined in practice, by analysis, before and after
dipping, of a certain number of mixtures most com-
monly employed.

When the formula for a mixture permitting de-
sired results to be obtained is thus found, the choice
of raw material to be dipped is also to be thought of,
as well as temperature of dipping, duration and tem-
perature of the reaction, etc., etc.

Here also, the experiments recalled above may
serve as a guide to results to be obtained.

D,g,t,.?<i I,, Google

THE NITRATION OF COTTON :5S

There always exist sensible differences between the
industrial manufacture of a product and the labora-
tory process which serves as a basis for it. A thou-
sand causes, varying from day to day, arise to modify
the qualities of the final product. At first one pro-
ceeds only by guess-work; it is only in the end, as
the result of the processes followed with method and
perseverance, that one becomes able to define with
exactness the effect produced by each one of a num-
ber of stated modifications.

With this line of thought a number of experiments
were made at the Angouleme laboratory upon the
production of nitro-celluloses. Much still remains
to be done, but the results obtained already permit a
more methodical procedure than in the past.

D,g,t,.?<i I,, Google

APPENDIX IV

THE DEVELOPMENT OF SMOKELESS POWDER*
Bj Lieuienant John B. Bbrnadou, U. S. Navy

The systematic development of improved ballistic
properties from progressive explosives constitutes
one of the most important ordnance problems of the
present day. The idea is beginning to gain ground
among us that hereafter we must look to the powder,
as well as to the gun, in our efforts to increase the
rapidity of flight and the penetrative power of pro-
jectiles; that we must consider the source of energy
at our disposal conjointly with the apparatus whose
function it is to convert that energy into useful work.

So long as the art of powder-making remained at
a standstill — as it practically did for several centuries
— ^while the practices of alchemy, rather than the prin-
ciples of chemistry, may be said to have controlled
the manufacture of all explosives, the best that could
be done was to follow the progress of mechanics in
efforts to effect ordnance improvement; guns were
built and powders were found to fire from them. To-

•Abstract of lecture delivered before the U. S. Naval W«r
College, July 30, 1897-

r:,9,N..<ib, Google

THE DEVELOPMENT OF SMOKELESS POWUBR :S7

day, however, not^nly is the composition of powder
undergoing modification, but new explosive com-
pounds, the development of which is based upon
chemical discovery, are coming into general use; the
results of investigations into the chemical and physical
properties of explosives, systematized and coordi-
nated by the methods of mathematical analysis, have
so increased our knowledge of ballistics, that de-
signers of ordnance are forced to accept new condi-
tions as factors of prime importance in the attain-
ment of ballistic effect.

For purposes of comparison, the old forms of pow-
der, such as black gunpowder, may be regarded as
imperfect mechanical mixtures of particles of the ma-
terials of which the powder is composed; the new ex-
plosives, as very intimate mixtures of the atoms of
those elements from the union of which into molecules
the substance of the explosive is formed. When the
old powder is employed as a fine dust, it bums with
great speed and violence; when agglomerated into
grains* it bums in a slow, progressive manner. If the
grainsof the old powders become dismtegrated before
they are completely consumed, tbrough efifects of heat
and gas pressure developed in the bore of the gun, the
grains crumble away; pressures become violent and
regular progressive combustion ceases to obtain.
Similar, but not identical, conditions exist for the
new explosives. In the form of dust they burn with

D,g,t,.?<i I,, Google

IS8 SAfOJCELESS POWDER

exceeding rapidity and great violence; when atl the
particles are decomposed simultaneously, they deto-
nate; by building them up into dense grains they may
be made, under favorable conditions, to burn pro-
gressively.

It was obvious from the start that many advan-
tages were to be obtained by the substitution of the
new explosives for the old as progressive powders.
The former burned up completely, leaving no resi-
due. Many of them made no smoke. Other condi-
tions being equal, these two qualities alone would
have been sufficient to justify their general adoption.
But other conditions were not equal. Up to a few
years ago the fact remained that no positive, certain
means of making nitro-explosives burn progressively
had been found. All known precautions could be ob-
served in the preparation; they could be built up into
dense grains with the greatest possible care; yet,
every now and then a charge of the powder would
detonate; that is, instead of burning progressively, in
accordance with the finished form of its grains, it
would burn as the dust from which the grains were
built up. A gun would be shattered, perhaps a life
or two lost, and then all confidence in the new ma-
terial would disappear, the chosen line of develop-
ment would be abandoned; no fundamental facts
would be left unchallenged to anchor new hopes
upon.

Until some way could be found, then, of firing a
nitro-compound from a gun with positive assurance
that detonation would not occur, there could be no

n,r.^^<i "/Google

TMM DEVELOPMENT Of SMOKELESS POWDER 159

change from the old powders to the new. This as-
surance was, however, obtained by the discovery that
nitro-cellulose, colloided and formed into grains of
regular size, would in all cases, if ignited in a closed
space, burn away in a progressive manner, at a rate
proportional to the form and dimensions of the grains
and to the conditions of their confinement. Two
proofs made the fact certain that colloids would not
detonate; first, that the grains of colloid powders
which were shot out of the gun without being com-
pletely consumed, preserved the original shapes, in re-
duced dimensions, of the grains of which the powder
charge was primarily composed; second, that not tens,
nor hundreds, but thousands of rounds of colloid pow-
ders, fired in guns or exploded in closed vessels, de-
veloped in every case pressures that could be shown
to correspond rationally, in accordance with the
theory of progressive combustion, to size and form
of grains and to dimensions of gun-chamber or ex-
plosion-bomb. To make these facts certain, pres-
sures were carried up beyond the 33,000-lb. limit al-
lowed for cannon; and in explosion-bombs to well
beyond 100,000 lbs. per square inch.

Now, as the only certain means yet found of avoid-
ing detonation and of assuring progressive combus-
tion is through the colloiding of nitro-cellulose, and
as nitro-cellulose alone can be colloided, it follows
that we are definitely Hmited in our choice of ma-
terial for progressive powders to a certain prepara-
tion of nitro-cellulose. It is true that a number of
substances, such as nitro-glycerin and nitrates of

D,g,t,.?<i I,, Google

I(S0 SMOXSLESS POWDER

metallic bases, may be distributed in minute particles
throughout the body of the colloid, and that im-
munity from simultaneous detonation may be se-
cured for the particles so distributed; but they all re-
main uncombined in the colloid — the nitrates, as the
sand or minute shells in the body of a sponge; the
nitro-glycerin, as the water in the pores of the
sponge. It is desired to emphasize by this compari-
son the fact that all the new powders, without excep-
tion, must be built up from some form of colloid
nitro-cellulose, whether they contain other ingredi-
ents or not. Thus, in the case of those powders con-
taining nitro-glycerin we may reduce the percentage
of nitro-glycerin to zero; that is, we may eliminate
it. If we were to remove the colloid nitro-cellulose
from such a powder we would have remaining nitro-
glycerin, which would detonate in the gun upon the
attempt to fire.

Nitro-cellulose, which is usually prepared by dip-
ping cotton into nitric acid, possesses a property
which the cotton, before dipping into acid, does not,
i.e., of dissolving in a number of substances. One
of these is acetone, a volatile fluid, with a character-
istic pungent and aromatic odor, somewhat suggest-
ing common alcohol in appearance and properties.
Another.solvent for a different kind of nitro-cellulose
is a mixture of ether and alcohol. If the clear liquids
which constitute the solutions in these substances be
evaporated, there will be obtained, not the nitrated
cotton, in its original fibrous form, but first, a
syrupy liquid, then a jelly, and finally, as dryness is

r:,9,N..<ib,G00gIe

THE DEVELOPMENT OF SMOKELESS POWDER l6l

approached, a solid translucent mass, varying in color
according to the variety of nitro-cellulose from which
it is prepared, frcmi a straw-yellow to a chocolate-
brown, and generally suggesting, in its various forms,
tortoise-shell. To such a substance the appella-
tion colloid, from its glue-like consistency, has been
applied.

The general name for the material produced by
steeping cellulose into nitric acid is nitro-cellulose.
One of its common forms is gun-cotton. Chemists
are well aware that there are many different kinds of
nitro-cellulose, but just how many there are no one
has as yet even been able to predict, the exact com-
position of cellulose and of its nttro-derivatives re-
maining among the yet unsolved mysteries of nature.
Three forms were originally assigned to it, the mono-,
di- and tri-, just as there were the three forms of
mono-, di- and trinitro-glycerin. A later investi-
gator (Eder) succeeded in proving the existence of
six. The authority of to-day upon the subject, whose
views are now generally accepted (Vieille), has form-
ulated eight. Now, just as there are many varieties
of nitro-cellulose, so there are many varieties of col-
loids. The nitro-celluloses themselves all look alike;
in their common pulped form they suggest fine white
flour. They can be distinguished from one another
with ease by the readiness with which some of them
go into solution in certain solvents, while others re-
main undissolved in these solvents like so much sand.
The fact that they possess such different properties
is accounted for in practice by proven differences in

r.,.:-7.y..y, Google

l62 SAtOJtELESS POWDER

chemical composition. It suffices here to state that
there are a number of different varieties of the sub-
stance which form a number of different colloids.
The question of composition will be considered later
in relation to the gases resulting from the combus-
tion of nitro-compounds.

We are familiar with the kind of nitro-cellulose
used for detonating purposes — gun-cotton. We are
also familiar with a form of colloid in common use to-
day as a material. I refer here to celluloid, now very
generally employed for the manufacture of a great
number of useful articles. The nitro-cellulose from
which celluloid is prepared may be made by steep-
ing cotton in weak acids, and is rather a combustible
than an explosive; it is a very different substance
from the high explosive, gun-cotton, which is pre-
pared from cotton by the use of strong acids. One sol-
vent used to make celluloid is a mixture of ether and
alcohol; the same solvent has no effect upon gun-cot-
ton, to dissolve which acetone must be used. We
have, then, two different types of colloid to start
with — celluloid (formed from weakly nitrated cellu-
lose by the use of ether-alcohol), and the acetone col-
loid of gun-cotton. It may be stated here that these
two types of colloids represent all that is important
in relation to colloid material for the manufacture of
smokeless powder, as the matter has been understood
up to a very recent date. The various colloids of the
eight varieties of gun-cotton above referred to range
themselves under one or the other of these two types.
We thus have two classes of colloid to experiment

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOXSIESS POWDER 163

with, as gunpowder, and all the information we pos-
sess in relation to them is the fact that, however they
may burn in the gun, yet they will not detonate.

Suppose that a number of rounds of powder are
prepared from the two colloids, how will they act
when fired from a gun of a given calibre? Let us as-
sume that we have at our disposal the instruments
commonly employed for the measurement of muzzle
velocities and of bore-pressures, the chronograph and
pressure gauges; we will then have, as a basis of com-
parison, first, the ratios V/P of velocities to pres-
sures*; second, cur personal observations of other
phenomena attending explosion.

Actual practice shows that the best results ob-
tained for the two powders in a given gun, by vary-
ing weights of charge and dimensions of grain, would
be about as follows:

GuD-cot ton-acetone colloid V/P = 3100/15-19;

Inspection of the results shows the existence of a
pressure-range of from fifteen to nineteen tons for
the acetone powder; this means that while no detona-
tion would occur, yet that pressures would jump be-
tween certain limits. Such a phenomenon is often
observed in the tests of brown powders for heavy

• A coav«ni«tit expreiiion for comparing, in a given gun, the
ballistic properties of different progressive powdert. — Frepre-
tenting velociliei in foot-seconds, and P, pressures in tons per
•qua re inch.

I Commonlj called " soluble nltro-cellolose."

D,g,t,.?<i I,, Google

164 SMOX£LESS POWDEK

guns. A powder of this character would be unsuitable
for general use by reason of pressure irregularity.

Upon firing the celluloid powder another and per-
haps worse inconvenience would be met with. Con-
siderable smoke would be developed and the interior
of the bore would be found lined, after each round,
with a heavy coating of soot, which, after one or two
shots had been fired and the gun had become heated,
would ignite after each succeeding round upon in-
gress of fresh air on opening of the breech, thereby
producing flaming at breech and muzzle.

Obviously, as gunpowder, neither the one nor the
other form of colloid is suitable. If they are to be
employed they must be improved. Irregularity in
pressures from the gun-cotton-acetone colloid is due
to brittleness; if we are to use this material we must
devise some means of toughening it. The celluloid
does not contain enough oxygen to consume its sub-
stance into gases; to use the latter we must put more
oxygen into it.

The original phases of the colloid powder question
thus present themselves. Neither the one nor the
other form of colloid proving suitable for direct
manufacture into powder, people began to try to im-
prove them by combining them, or by adding foreign
substances to them. It was well understood that no
form of gun-cotton, however highly nitrated, con-
tained enough oxygen to effect its own complete
combustion — the conversion of its carbon into the
higher oxide of carbon, CO,. The first idea of the
experimenter was to add enough oxygen to the nitro-

n,,:-A-..>yGoogIe

The development of smokeless powder 165

cellulose to thus complete its combustion, and this
unfortunate attempt led to many years' delay in the
development of smokeless powder. It started in-
vestigators off upon a wrong track; complete com-
bustion was one thing, and the work necessary to de-
velop highest velocity with lowest bore-pressure, an-
other.

With the purpose, then, of improving ballistic
qualities of powders by causing them to consume
completely and to develop regular pressures, experi-
menters in different countries began to try the effect
of introducing into the colloid various foreign sub-
stances, — generally, oxidizing agents, such as ni-
trates of metallic bases; sometimes, when the mix-
tures became too violent in their action, a substance
rich in carbon, called a deterrent, was added. Such
work was a good deal like groping in the dark.
There was no method in it. But there was one great
incentive to keeping it up, viz., the fact thereby es-
tablished that the addition of these nitrates to the
colloids actually increased the velocity developed for
a given bore-pressure, whatever the inconveniences
attendant upon the employment of these mixtures as
powders may have been.*

To establish a comparison between the ballistic
efficiencies of the two types of pure colloids above

• The Increase ia muzzle velocities (or a given bore-pressure to
be attained by incorporating certain quantities of metallic ni-
trates, nitro-glycerXD, etc., into tiie body o£ the colloid, con-
ttitutes a special phase of development of progressive powders.
which will be discussed in a subsequent paper.

D,g,t,.?<l I,, Google

l66 SJ^OKELESS POWDER

cited, and of certain" compound colloid powders into
the substance of which metallic nitrates or other oxy-
gen-carriers are incorporated, the tabular record of
performances of powders of these classes is submitted
on page 167. Note is made therein of objectionable
features developed for each of the explosives named.

Referring to the table we find powders A and B
with properties as already described. ■ The K, BN,
and cordite all make good balHstic showings, giving
velocities greater by about 300 ft. sec. for a de-
veloped pressure than the former.

The last line of the table shows that each of the
powders possesses certain unfavorable quaHties which
miHtate against its adoption for service use. The
gun-cotton acetone colloid develops irregular pres-
sures ; the ether-alcohol colloid of soluble nitro-
cellulose deposits soot; the K and BN produce some
smoke and bore-deposit. Cordite contains a volatile
liquid, nitro-glycerin, which develops great heat
upon combustion. Now the development of highest
velocity at lowest pressure is most important, even
if obtained at the expense of the production of cer-
tain partially unfavorable conditions; but there was
a further incentive to progress at this stage of de-
velopment — the fact there had been found a form of
pure colloid, unadulterated by admixture with other
substances, which, while developing high velocities
at moderate pressures, possessed the full round of
good qualities necessary in a service powder.

The end sought tor in the development of gun-
powder is the attainment of the capability of deliver-

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER 167

K

-Mi

•sss?

11
a.

=

11=

1
II

V

"

K

(Primitive type.
United States.)

Blend of nitro-cel-
luloscs coNoided
in acetone, wich
metallic nitrates
added

1

It

.

1

"1"

1

=

1

Q

<

1

Is

II

a,

1
1

D,g,t,.?<i I,, Google

1 68 SMOKELESS POWDER

ing most accurately in a given interval of time the
greatest number of most powerful blows; this result
to be effected with minimum risk to gunners and with
least possible injury to gun. Hereby is implied the
fulfilment of a number of important independent
conditions, no one of which may be overlooked in the
effort to successfully accomplish the object sought.
These conditions corre^ond to qualities possessed
by a powder, and may be given, with their opposites,
a general grouping under headings as follows:

Table II

QUALITIES OP POWDBKI

.

.

,

4

,

PodtlTC j

No«Jl.biUtT
Dcunuion

Sroiloa

mialmum
mldue

Good keep-

MuiBUB

Low «lue

The first condition is of paramount importance
and limits us to the employment of a colloid material.
The second represents the fact that the greater the
heat developed the greater the wearing away of the
inner surface of the bore. The third requirement
means obviation of bore-deposit, which operates to
reduce rapidity of fire by necessitating more or less
frequent sponging, and to diminish accuracy of prac-
tice through the formation of smoke. The fourth re-
quirement, stability, is all-important, when we re-
member that the ship must carry safely her store of
powder for at least a cruise, and for the reason that

r:,9,N..<ib, Google

THE DEVELOPMENT OF SMOKELESS POWDER 169

when powders begin to decompose they lose their
homogeneity and crumble — which means an end to
regular-pressure development.

Let us now take up requirement fifth — the attain-
ment of maximum propulsive effect — and see what it
leads to. What causes the expulsion of the projec-
tile from the gun? The expansion of powder-gases.
What limits our employment of the expansive force
of these gases? The attainment of the limiting bore-
pressure, this limit being commonly set at fifteen tons
per square inch. What represents the greatest
amount of work in the form of velocity? The great-
est amount of gas-expansion in the gun behind the
projectile.

We desire, then, the greatest amount of gas ex-
pansion, but we are limited as to the rate of this ex-
pansion; that is, we must not let it develop in the
bore a pressure greater than fifteen tons in the gun-
chamber or upon the interior walls of the piece. This
is tantamount to saying that to produce maximum
velocity we require the evolution, at a suitable lim-
ited rate of expansion, of the greatest possible
volume of gas, the expansion of the gas constituting
under these conditions the propelling impulse.

It may be stated here that we possess, within limits,
the power of controlling the rate of combustion of
colloid powders tiy varying certain conditions re-
lating to combustion, the principal of which are (i)
the size of the grains of which the charge is com-
posed, (2) the volume of the powder-chamber, {3)
the length of the bore of the gun, (4) the weight of

D,g,t,.?<i I,, Google

I70 SMOKELESS POWDER

the projectile. Granting, then, that we possess
within limits the capability of controlling the rate of
evolution of the powder-gases, we are led to the fol-
lowing conclusion; that the best smokeless powder
is that stable colloid which, for a given weight of its
substance, evolves in the bore of the gun at the most
suitable rate of evolution and expansion, the greatest
volume of gas, the said evolution being accompanied
with the development of the least heat.

We are led by this deducticMi to regard the action
of the powder from a new standpoint. Besides con-
sidering what a powder is composed of, we must now
consider what gases it is converted into upon decom-
position, and what volumes of these gases it gener-
ates. Most important of all, it leads us to conduct
experiments for the purpose of ascertaining what
colloid will, for a given weight of its substance, liber-
ate the greatest volume of gases.

Here was one starting point for a series of experi-
mental researches culminating in the discovery of an
efficient smokeless powder. Another line of experi-
mental approaches to the same end connected the
efforts to toughen the substance of colloid films con-
taining sufficient oxygen to effect their own com-
plete combustion, with a view to the attainment of
increased regularity in developed pressures; a third
related to the determir-ation of the causes of certain
ballistic phenomena hitherto unexplained, e.g., that
acetone colloids developed, in some cases, greatly
improved ballistic qualities, after the lapses of periods
of from six to twelve months from time of manufac-

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER I7I

ture. These several lines o£ experimental investiga-
tion proved in the end to converge towards the at-
tainment of a common result — the development of a
special form of nitro-colloid that possessed the
toughness and therefore the regularity of burning of
celluloid, and that contained enough oxygen to con-
vert its substance, upon ignition, into wholly gaseous
products — which the celluloid did not — and that
liberated not only the greatest volume of powder-
gases at the most suitable rate, but the greatest
volume of gases that can be evolved by any colloid
at any rate of combustion, whether these colloids
contained or did not contain nitro-glycerin, metallic
nitrates or other substances.

The questions now present themselves: in what
ways do we possess the control of kind and amount
of gases evolved upon the combustion of nitro-
cellulose and of its colloids; how does the constitu-
tion of these gases vary; what are they?

It has been already stated Ihat the exact chemical
formulae for cellulose and its nitro-derivatives have
not yet been written. That for cellulose may be ap-
proximately expressed as C(„H,(„0;„ , where n is an
undetermined or indeterminate numerical quantity.
When cellulose is steeped in nitric acid or in a mix-
ture of nitric and sulphuric acids, it is converted into
the substance the composition of which may be ex-
pressed asasC6,H,„^,0j«(N0j)a,. These two expres-
sions, Cs,H,„0,, and C6,H,o,™,05,(NO,)„ , may be
considered in comparison with one another. But
contain the same quantity of carbon; the quantj-

■'..lyGoogle

172 SMOKELESS POWDER

ties present of the other elements are changed by
nitration; an atoms of hydrogen are displaced by
an equivalents of a combination of nitrogen and
oxygen (NOj), This additional oxygen from the
NOj acts to supply the energy that converts the
cellulose into an explosive, and enters into its sub-
stance in combination with a certain quantity of nitro-
gen. Why it carries the nitrogen with it we do not
know, but it is a chemical fact that it does so — the
fact upon which the designation of the new ex-
plosives as nitro-derivatives or nitro-explosives is
based.

Upon the ignition of the nitro-cellulose or its
colloid the nitrogen is set free; the hydrogen com-
bines with its equivalent of oxygen and appears in
the air as steam; the remaining oxygen unites with
the carbon to form gaseous oxides of carbon. If
there be not enough oxygen to consume all the car-
bon into gas, part of the latter is deposited as soot;
this result was obtained in the attempt to employ
celluloid as gunpowder. If there is enough oxygen
to consume all the carbon into gases, we have, aS
products of combustion, a mixture of the gaseous
oxides of carbon, of which there are two, CO^ and
CO.

The property possessed by carbon of combining
at high temperatures with intense energy with
oxygen, to form gaseous oxides, is the fact upon
which the practical development of explosives de-
pends; there are many explosives that contain neither

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER \^%

carbon nor oxygen, but with these we have .as yet no
practical relations in ordnance matters.

It has been stated already that the attempt to ob-
tain what is called complete combustion for nitro-
cellulose colloids by incorporating oxidizing agents
into them had misled investigators, who confounded
the attainment of complete combustion with the de-
velopment of maximum velocity at lowest pressure.
" Complete combustion " means the conversion of all
the carbon into the higher oxide of carbon — car-
bonic acid, CO2 — a dense gas about 1,9 times as
heavy as the air, the formation of which is accom-
panied with the development of a high degree of heat.
The complete combustion of carbon into carbonic
acid gas with the corresponding evolution of a great
amount of heat is the characteristic of the combus-
tion of nitro-glycerin. The lower oxide of carbon,
CO, is a gas much less dense than carbonic acid, pos-
sessing a density of about 1.4 times that of air. Sup-
pose that )ve have a given weight of a compound of
carbon and oxygen, with the elements taken in such
proportions as to produce, on ignition, complete
combustion into carbonic acid gas, CO2, with the ac-
companying evolution of a large amount of heat;
let us also suppose that we have an equal weight of
compound of the same elements in such proportions
as to develop, on ignition, the lower oxide of carbon,
carbonic oxide, CO; then, the latter compound, de-
veloping the lower oxide, would liberate a volume of
gas nearly 1.9/1,4=1.36 times greater than the
former. The greater heat produced by the forma-

D,g,t,.?<i I,, Google

174 SMOXELESS POWDER

tion of the carbonic acid gas would cause the volume
of that gas evolved to be the more expanded, but,
at the same time, and this is a fact of crucial impor-
tance in the present work, the greater heat would
cause the gas to be generated at a more rapid rate,
in fact, at an extremely rapid rate; and what we re-
quire is a low, regular rate of gas evolution to pre-
vent our exceeding at any time the set limit of per-
missible bore-pressure.

In our effort to generate from colloid nitro-cellu-
lose the greatest volume of gas at the most gradual
rate of expansion, we must seek, then, (i) to avoid
the formation of CO^ when CO may be formed in
lieu thereof; (2) to avoid the formation of free car-
bon; and (3) to generate the maximum volume of the
lower carbon oxide. If we give due consideration
to the amounts of water and of nitrogen formed
simultaneously with the oxides of carbon, we shall
find that the form of nitro-cellulose developing the
greatest volume of gas at the most suitable, rate, cor-
responds to the formula C3oH3g(N02)i202B, which
breaks up on decomposition into 30 CO -j- 19
HjO -H 12 N.

This materia! is a new type of nitro-cellulose,* de-
veloped by experiment to meet ballistic require-

• This special form of nitro-cellulose, which corresponds to a
content of nitrogen of 13.44 PC cent, and which was first devel-
oped in Russia hy the eminent chemist, Professor D. Mendeltef,
has been independently developed at the Torpedo Station,
through the study of efEects of variation of times of immersion,
temperatures of nitration and of washing, and strength of acids
employed in the niiration of cellulose,

r:,9,N..<ib,G00glc

THE DEVELOPMENT OF SMOKELESS POWDER I75

ments, which contains just enough oxygen to convert
its substance into a gaseous body. Its formation
from cellulose depends upon strengths of nitric and
sulphuric acid, temperatures of reaction and time of
immersion of the cellulose in the acids from which the
material is prepared. With ether-alcohol it forms a
colloid that possesses, on the one hand, the tough-
ness, and therefore the capability of development of
regular pressures, of celluloid; and on the other the
capability of consuming into wholly gaseous prod-
ucts that characterizes the gun-cotton acetone
colloid; while as a powder it develops, with present
types of guns, excellent values of V IP of about
2400/16. Briefly, it may be described as a celluloid
containing enough oxygen to convert its substance
(when it is consumed out of contact with the atmos-
phere) wholly into gaseous products.

It was stated in a preceding paragraph that the bal-
listic effect produced by a progressive explosive de-
pended directly upon the volume of gas it evolved
upon combustion, but was not directly dependent
upon the attainment of complete combustion. As-
suming total conversion from solids into gases, and*
non-liability to detonation, pyrocellulose was shown
to be the form of nitro-cellulose best adapted for con-
version into smokeless powder. As this material con-
tains only enough oxygen to convert its carbon into
carbonic oxide, CO — less than gun-cotton, which
converts its carbon partly into carbonic acid gas,
CO2, and partly into carbonic oxide, CO — the at-
tainment of maximum efficiency from nitro-cellulose

D,g,t,.?<i I,, Google

i;^ SAfOKELESS POWDER

was thus shown to be accomplished through a reduc-
tion from a maximum to a mean in the quantity of
oxygen capable of being incorporated into nitro-
cellulose.

On the other hand, it was stated that the incor-
poration of certain quantities of oxygen-carriers
(nitro-substitution compounds other than nitro-cel-
luloses, such as nitro-glycerin and nitrates of metalUc
bases) into colloid nitro-cellulose, led to the attain-
ment of an increase in initial velocity of projectile for
a given developed bore-pressure. As nitro-glycerin
furnishes a surplus of free oxygen to aid in complet-
ing the combustion of the gases from the nitro-cellu-
lose, while the nitrates surrender oxygen on applica-
tion of heat, it would appear in this case that the at-
tainment of a more complete combustion led to im-
provement in ballistic effect.

We are thus brought face to face with a seeming
contradiction — how, on the one hand, we must re-
move oxygen; how, on the other, we must add oxy-
gen to a progressive explosive, in order to obtain
maximum ballistic effect therefrom. In order to
reconcile these apparently contradictory statements
we must consider the manner of decomposition of the
explosive in both cases.

One chief characteristic of pyrocellulose Is its
homogeneity. It represents no mixture of explosives
and combustibles, such as are presented by other
forms of powders, and it is converted directly by com-
bustion into a set of gaseous decomposition products
that may not be varied in amount and kind. Under

D,g,t,.?<ii„GoogIe

THE DEVELOPMENT OF SMOKELESS POWDER 177

these conditions the ballistic effect of the expanding
gases from pyrocellulose may be referred to quantity
of charge, area of ignition-surface, weight of projec-
tile, calibre of gun, and volume of powder-chamber.
Other conditions affecting developed pressure and
velocity are bore-friction and resistance of the pro-
jectile to rotation through inertia.

The gun may be regarded as a gas-engine in which
the walls of the chamber and bore form the cylinder;
the projectile, the piston. The expanding powder-
gases perform work by imparting velocity to the pro-
jectile, the inertia of which they overcome just as gas
by its expansion in the cylinder overcomes the inertia
of the piston and the parts linked thereto. In the en-
gine the gas is admitted alternately, first at one end of
the cylinder and then at the other; in the gun it is ad-
mitted in rear of the projectile but once, so that the
gun is an engine of a single stroke. In the engine
the steam is admitted into the cylinder through a
valve, and, after the lapse of a period of time less than
that required for a full stroke, admission is cut off
and wor^c for the rest of the stroke is performed ex-
pansively; in the gun the charge of powder consti-
tutes both the gas itself and the valve that admits the
gas — for each grain of powder may be considered as
a notch of opening of a valve; the more grains there
are the greater the ignition surface, the greater the
rate of emission of gas, or the greater the number of
notches the valve is open.

The action of nitro-cellulose powder-gases in im-
parting motion to the projectile is that of the gas in

r:,9,N..<ib, Google

178 SMOX BLESS POWDER

the engine cylinder. The decomposition products
are evolved at a high pressure, and act to propel the
projectile, just as the gas or vapor drives the piston
in an engine. Thus far the two cases are in parallel;
they differ in that the space occupied by the gas in
the gun is constantly increasing, both through the
effect of the motion of the projectile along the bore
and from the increase of chamber space due to the
melting away of the powder charge, while space in
the engine cylinder is increased through the motion
of the piston and through connection with the valve
before cut-off. As shown in Table I, the ballistic
value of gun-cotton colloided in acetone (for a given

eun) was-— ; that of colloided soluble nitro-cellu-

^ ' 15-19

lose, containing not enough oxygen to convert its
carbon wholly into carbonic oxide, CO, was ■ ? -.
Under similar conditions of firing, pyrocellulose de-
veloped a value of VfP = ~rz-- It may be urged

that the ballistic superiority of the latter colloid as
compared with that of the two former is not wholly
attributable to character and volume of evolved gases,
as the acetone colloid is brittle, and that prepared
from soluble nitro-cellulose is somewhat brittle, and
deficient in oxygen, while pyrocelluloid is of a tough,
leathery consistency, capable of withstanding high
pressures without premature disintegration. Never-
theless, as these colloids prove inferior to the pyro-
colloids for lower pressures of about 10 tons per

D,g,t,.?<i I,, Google

THE DEVELOPMENT OE SMOKELESS POWDER 179

square inch, at which the effects of brittleness are not
perceptible, and for which they all afford pressures
regularly proportional to develop velocities, it re-
mains that magnitude of volume of evolved gases is
a factor of prime importance in the attainment of bal-
listic efficiency.

COMPOSITE POWDERS

The results of incorporating an oxidizing agent or
oxygen-carrier into colloids merit special study. Sup-
pose that a given nitro-cellulose be colloided and
formed into strips of a number of definite thicknesses.
If these strips be collected separately and dried, we
may prepare from them series of rounds, each series
composed of different weights of strips of some one
thickness. If the length and breadth of the strips be
great in relation to their thickness, we need consider
only the latter element of dimension in relation to
their mode of combustion.*

• We have (Glenoon, Interior Ballislics. chap. VI, pp. 59. 60)

'■ <Hy) = «r(i - V + ;'?''-■. ).

where y is the fraclional pari of the least dimension of the grain
burned up to any moment; 0(j-) the fractional part of the whole
grain burned up to the same moment; and a, y, and ^, constants
depending upon the form of the grain.

If the grain be a rectangular parallelopiped with a square base,
and the altitude as the least dimension, ne hare

where x is the ratio of the altitude to the side of the base."
Applying the above to the present case we find tbal if the alcl-

r:,9,N..<ib, Google

l8o SMOrSLESS POWDER

Upon firing series of rounds of the several powders
from a given gun we obtain the following results as
to their manner of explosive action:

I. — Strips of over a certain mean thickness will be
only partly consumed in the bore; the unconsumed
remnants will be projected burning from the g^n, to
be quenched in the cool outer air, where-they fall un-
consumed to the ground and may be picked up at
various distances from the piece in front of the muz-
zle, possessing the original form (in reduced dimen-
sions) of the grains of which the charge was origin-
ally composed. Such powders develop low bore pres-
sures and afford low muzzle velocities. In point of
work performed they are equivalent to smaller
charges of quicker powders. It may be remarked
that no work is done in raising the temperature of
the unconsumed portions of the grains, for if the tem-
perature of the latter be raised but a few degrees, the
ignition point of the explosive is reached and its sub-
stance would wholly disappear.

2. — Strips of under a certain mean thickness are
totally consumed in the gun. They develop high
pressures for low velocities. The thinner the strips
the less the weight of charge required to develop the

tude be considerably diminished {x approaclics zeto) ire have the
case of the thin plate; and that the constants approach the values

or <Kr) = r-

But y depends alone on the thickness of the plate, therefore
the speed of combustion of a plate is a linear function of its least

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER l8l

limiting permissible pressure, on account of the
greater initial surface presented by the thinner strips,
which occasions a high initial gas development,

3. — A certain mean thickness of strip will be found,
for which, at a set limit of pressure, a minimum
weight of powder will develop the greatest velocity
that can be developed at that pressure. If strips of
other thicknesses develop practically identical veloci-
ties and pressures for the same pressure limits, it will
be by burning greater weights of powder. Such a
powder may be designated a maximum powder, for
the material from which it is prepared and for the gun
from which it is fired.

Suppose, then, that colloided gun-cotton of nitra-
tion N= 13.3 develops in a given gun a maximum

value VIP = — — , what will be the effect of incor-
porating into such powder a certain quantity of nitro-
glycerin, or of metallic nitrates such as barium and
potassium nitrates? Assume that during the process
of coUoiding the requisite quantity of nitrates be uni-
formly incorporated throughout the substance of the
pasty mass, which is subsequently formed into strips,
as before. For this material we shall find that the

maximum powder develops a value of V/P =

2100
as agamst — — - for the pure colloid, a gain in velocity

of 300 ft. sec. for a given pressure; in energy, ( ),

of about 30 per cent,

D,g,t,.?<i I,, Google

l82 SMOKELESS POWDER

If, in lieu of nitrates, we incorporate nitro-glycerin
into the colloid, we will obtain a pasty mass that can
be worked conveniently into the form of rods or
cords, whence the name " cordite," applied to one of
its best known types. Cordite, as used in England,
consists of

Nitro-glycerin 58 parts

Gun-cotton 37 parts

Vaseline 5 parts

Such a powder, fired under the above conditions,
develops a value of V/P = — — approx.

There is one characteristic of powders, such as the
K and the French BN, containing nitrates, to which
attention is to be directed. The nitrates contained in
these powders exist in them in a state of suspension;
in an undissolved state. For the BN the microscope
reveals minute crystalline particles uniformly dissem-
inated throughout its mass; the barium nitrate em-
ployed in the K powder is insoluble in the coiloiding
agent, acetone, and is also insoluble in the colloid, in
which it is held in a state of suspension and of uni-
form distribution. ■

In the case of the nitro-glycerin powders it is
known that the nitro-cellulose is not in true solution
in the nitro-glycerin. In this connection the follow-
ing quotation from an authority upon nitro-glycerin
powders, Mr. Hudson Maxim, may be cited:

" In the very early smokeless powders, especially
those mad« of compounds of soluble pyroxylin (gun-

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER I83

cotton) and nitroglycerin, it was supposed that the
nitro-glycerin actually held and retained the pyroxy-
lin in solution, but it has since been learned that the
nitro-glycerin is held by smokeless powders, whether
made from high- or from low-grade gun-cottons, in
much the same manner as water is held by a sponge;
in fact, the pyroxylin exists in smokeless powders in
the shape of a very minute spongy substance, and the
nitro-glycerin is held in a free state within the pores
cf this sponge."

" It is possible even with powders containing as
little as 25 per cent, of nitro-glycerin, to squeeze out
the nitro-glycerin in a pure state by subjecting a piece
of this powder to great pressure between smooth
steel plates."

The quantity of nitro-carrier (nitrate or nitro-sub-
stitution compound other than nitro-cellulose) consid-
ered necessary to the production of good ballistic re-
sults, as exemplified in certain known powders, may
be tabulated as follows:

Cordite Nitro-glycerin $8

Maxim Nilro-glycerin lo to 35

BN Barium- and Potassium nitrates 2t to 3S

K Barium nitrate 14.85

The composition and ballistic properties of the
three classes of explosives — pure colloids, colloids
containing metallic nitrates, and colloids containing
nitro-glycerin — may be compared as follows;

D,g,t,.?<i I,, Google

SMOKEI-ESS POWDER
Table IV

Pmc Colloid

K

BN

Conlite

Gun-cot-

GUD-COl-

Inaol. nitro-

Nitro-Rly.

cellulose, 38.67

cerLn, 58

Soluble ni-

soluble

84.as

Soluble nitro-

Gun-cot-

lulose,

cellulose, 33.83

Sod.carb, i.w

Barium

Vaseline, s

Solvent, res-

Barium

nitrate, I4-3S

Potassium

Calc. carb., i.so

niirate, 4.S4

Calc. carb.,3.6s
Volatile, i.ag

ioo.i»

Type

Pure

Colloid

Metallic Nitrate

Metallic Nitiate

Nitrc^l^n

Manner
of incor-

of oxjr-
gen-car-

V
T

1S-19

Solid undis-
solved parti-
cles, uniform-
ly distributed
throughout
colloid ma-
trix

8400

IS

Solid undis-
solved parti-
cles,unirorm-
Ijr distributed
throughout
colloid ma-
trix

15

Undissolved
particles
held in sus-
pension like
water in
sponge

a400
15

Remembering what has been said in relation to the
ballistic performance of the varieties of powders cited,
we are led to the following conclusion:

Thai minute particles of an oxygen-carrier uniformly
incorporated into a mlro-colloid and held in suspension

D,g,t,.?<l I,, Google

THE DEVELOPMENT OF SSfOXELESS POWDER iSj

m an undissolved state throughout the body of the latter,
render more progressive the combustion of the nitro-
colloid into which they are incorporated.

For convenience of reference I shall refer here-
after to the oxygen-carrier held in suspension in the
colloid as the accelerator. Viewed in the light of the
principle here enunciated, the several powders we
have been considering are all similar variants of the
pure colloid. The remark of the compounder, " that
a little nitro-glycerin certainly does help the powder
along," is now the more readily comprehensible.

The methods commonly employed for co-ordina-
ting natural species may be applied, by way of illus-
tration, to the classification of the various types of
progressive explosives, to establish their relations to
one another, and to indicate the lines along which
advances have been effected.

We shall neJtt consider how the accelerator acts to
develop increased velocity without developing in-
creased pressure,

I. — It has already been shown how it is possiUe
with powders containing as Uttle as 25 per cent, of
nitro-glycerin to squeeze out the nitro-glycerin in a
pure state by subjecting the powder to great pressure
between smooth steel plates.

If it be possible to extract nitro-glycerin by appli-
cation of pressure from powder in which it is incor-
porated, then there will be a tendency to flow in the
direction of leastpressure from the instant of ignition
of a charge to that of its complete combustion. This
would mean, first, flow from within outwards in the

. D,g,t,.?<ii„Google

SMOKELESS POWDBJt

III.

fiJl si il Hill illl -

P =1

j Ills si

ml? |2i lylill

sSli

Illl

Illl

lltiili

ill

J I

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER 187

gun-chamber, where a relatively large proportion of
the nitro-giycerin would be consumed; second, flow
in the direction of the windage, where the quantity of
nitro-glycerin consumed would also be relatively
great. Such action accounts for the rapid erosion of
the surfaces of gun-chamber and rifled bore when
powders containing nitro-glycerin are employed.

2. — The eminent Russian chemist, Professor D.
Mendeleef, developer of smokeless powder in Russia,
in a paper upon pyrocellulose powder, says:

" The chemical homogeneity of pyrocollodion
plays an important part in its combustion, for there
are many reasons for believing that upon the com-
bustion of those physically but not chemically
homogeneous materials, such as nitro-glycerin pow-
der (ballistite, cordite, etc.), the nitro-glycerin is de-
composed first, and the nitro-cellulose subsequently
in a different layer of the powder. The experiments
of Messrs. T. M. and P. M. Tcheltsov at the Scientific
and Technical Laboratory show that for a given
density of loading the composition of the gases
evolved by nitro-glycerin powders varies according
to the surface area of the grains (thickness of strip),
a phenomenon not to be observed in the combustion
of the pyrocellulose powders. There is only one ex-
planation for this, viz., that the nitro-glycerin, which,
possesses the higher rate of combustion (Berthelot),
is decomposed sooner than the nitro-cellulose dis-
solved in it. This is the reason why nitro-glycerin
powders destroy the inner surfaces of gun-chambers
with such rapidity."

D,g,t,.?<i I,, Google

1 88 SMOXELESS FOWDER

We conclnde from the above that the nitro-glycerin
incorporated into a colloid bums more rapidly than
the nitro-cellulose forming the colloid. More nitro-
glycerin is consumed with one part of the charge than
with another. During the first period the products
of combustion evolved in chamber and bore are
largely those of nitro-glycerin; during the second,
those of nitro-cellulose.

Moreover, as both materials exist in an uncom-
bined state, although in one of intimate admixture;
as both decompose wholly into gases, while each con-
tains sufficient energy to continue its own decompo-
sition, once that decomposition is begun, there is no
reason why the rates of the two decompositions
should be equal; it would rather appear that each
substance should decompose at the rate peculiar to
itself, so far as it was able, under existing conditions
of heat and pressure, to effect a separation of its sub-
stance from the mixed mass of the powder.

Conditions point, therefore, to there being two in-
tervals in the decomposition of the charge, during one
of which a maximum quantity of nitro-glycerin, and,
during another, a maximum quantity of nitro-cellu-
lose is burning.

In what follows it is not intended to attempt more
than to indicate the mode of progressive combustion
as implying the superimposition of maxima and
minima of effort. This may be represented graphic-
ally in the present case as follows:

r:,9,N..<ib, Google

THE DEVELOPMENT OF SMOSTELESS POWDER I

N NITSO-CELLULOSe

The result of the combination of the conditions
here indicated would be the imparting of a double im-
pulse to the projectiles due to the successive occur-
rence of two maxima of acceleration. Considered as
to their limit of possible range, the successive im-
pulses may occur incrementally, so that the accelera-
tor may be expressed in the form

<t>{p')

de

-^''C/O

dt*'

where p' represents the pressure due at any instant to
the combustion of the nitro-glycerin ; p", that due to
the nitro-celluiose.

The projectile may be regarded as receiving a third
impulse, resulting from the chemical combination of
the gases evolved by the mtro-glycerin and the nitro-
cellulose. According to the researches of Messrs.
Macnab and Ristori (Proc. Royal Soc, vol. LVI,
p. 8), the decomposition products of nitro-glycerin

CO,

CO

CH,

o

H

N H,0.

5;-6

2.7

18.8 20.7

D,g,t,7?db,Goi:igIe

SMOKELESS POWDER

And from the same source we obtain the decomposi-
tion products of nitro-cellulose (N = 13.3) as

CO, CO CA. O
29.27 38.52 0.24 —

N H,0
13.6 16.3

What may be called the third impulse would repre-
sent the combination at a high temperature of mul-
tiples of decomposition products developed in the
ratios

ifCO,

CO CH, O
— — 2.7

H

^[29.27 38.52 0.24

N H,0-j
18.8 20.8J

13.6 16.3]

These phases may be indicated graphically as fol-
lows:

Accelerated colloids of K and BN types containing
metallic nitrates are next to be considered. We may
assume that the nitro-colloid into which minute par-
ticles of a nitro-carrier of this type are cemented itself
burns in approximation to the law of decomposition
of the colloid. This state of affairs is similar to.

D,g,t,.?<l I,, Google

THE DEVELOfiMEUT Of SMOJCELSSS POWDER 19I

though not identical with, the preceding; in the
former, both nitro-glycerin and nitro-cellulose are
able to effect their own decomposition, evolving
gases that recombine; in the latter, the nitro-cellulose
alone possesses this property, the metallic nitrates
surrendering their oxygen through the effect of heat
developed during decomposition of the colloid. The
successive reactions may be represented as follows:

Instead of three maxima of effort there are two
maxima and one minimum, the maxima representing
the combustion of the nitro-cellulose and the subse-
quent combination of the gases therefrom with the
oxygen of the barium nitrate; the minimum, the ab-
sorption of heat expended in decomposition of the
barium nitrate.

A comparison of the diagrams shows that the proc-
esses of combustion in the case of colloids containing
nitro-glycerin and of those containing metallic ni-
trates are similar. Both represent aggregates of
work resulting from successions of independent de-
compositions. For such powders an element of time
enters into our conception of chemical action; what
the ultimate products of combustion are depends
upon the order of occurrence of successive evolutions

D,g,t,.?<i I,, Google

192 SMOKELESS POWDER

of various volumes of different gases at high tem-
peratures.*

The base of the projectile is subjected to a series of
impulses due to the development of successive waves
of pressure; the result is an increased initial velocity
for a given developed pressure, the acceleration be-
ing sustained throughout a comparatively longer
period of time.

Those familiar with experimental development of
ordnance during recent years remember a type of
multi-charge gun the construction of which seemed
based upon a favorable combination of correct prin-
ciples, but which was rejected on trial, as its practical
disadvantages were found to outweigh by far its ad-
vantages. I refer to the Lyman-Haskell multi-charge
gun, a weapon supplied with a number of pockets dis-
tributed along the axis of the bore. In each pocket
a charge of powder was placed; it was supposed that
the projectile, by uncovering successive pockets in its
flight, would cause their contents to ignite and thus
furnish successive accelerating impulses to increase
its velocity.

From what has been already said in relation to the
principle of successive combustion, it will be seen
that the employment of charges of accelerated pow-
der, like those above described, in a gun of present-
day type, represents the limiting extension of the
multi-charge principle. In relation to their succes-
sive combustions, the nitro-glycerin and the nitro-

"See extracis from paper by Prof. Mendel6ef, p. 33.

D,g,t,.?<i I,, Google

THE DEVELOPMENT OF SMOKELESS POWDER 193

cellulose may be considered as sub-charges, con-
tained in independent chambers or pockets, or dis-
tributed throughout a very large number of small
pockets.

The principle already stated, as established by the
study of the ballistic action of accelerated or com-
posite powders, may be now amplihed as follows:

Minuk particles of an oxygen-carrier, uniformly in-
corporated into a nitro-colloid and held in suspension
throughout the mass of the colloid in an undissolved
state, act through their independent combustion in such
a manner as to render more progressive the combustion
of the colloid into which they are incorporated.

D,g,t,.?<i I,, Google

I,, Google

INDEX

Accelerator 18S

Acid, Dttric, table ehowiog scticm and results (rf mixtures of . . . 83

NitnAydric 109

Sulpho-DitTic, table showing actiiHi and results of mix-
tures ai 87

Acid batli, table showing composition of, in relation to yield of

nitrogen dioxide 132

Alcobol, abstdute, as a solvent S2

Actim of, in facilitating solution 43

Alkalies, action oi, on cdlulose 46

AmmiHiium compounds as materials for explosives 108

Ammmium nitrate in Bmokeless powders 122

Attainment of maximum prt^ulsive etteCt 169

Ballistic efficiencieB of pure colloids and ctMDpound colloids

containing accdenLtors, table lowing 167

Ballistic properties and composition of explodves, table show-
ing 184, 186

BalliBtJte 117

Benztd derivatiTce as materiala toe «xplarives 121

Celluloee 6

Action of alkaline hydrates on 46

As a base for Huokdsss powders 12S

Composition <rf. 57

CtmditionB governing formolatjon t4. 66

Constitution of 21

Dinitrate 14

ElectrtJytic strain in 50

Heianitrate 12

»9S

D,g,t,.?<i I,, Google

196

Cellulose hydrate, compo^tion of 67

Ejdratioii of 4S

Incompletelj nitrated 92

Molecule, theory ot 37

Nitrates _ 74

Nitrates, compositiaa of 11

Nitrates, votume <A nitrogeo. diodde disengaged per gram

by 128

Pentajiitrato 13

Btnieture of 21, 69, 60, 61

Structure of polymeric forma of 63, 64

Tdjanitrate 13

Thlocarbona.t« 48

Trinitrate 13

Typa 69,70

Cocoa powder, gases evolTed by 101

Cold, action ot, in accelerating solution 61

Solubility of nitro-celluloses in the 43

Solubility of n&tro-hydrocelluloee in the 41, 42

Stdubility of pyrocdiuloae in the 43

Collodion cotton 7

Collodion-pyroKylin 7, 13

Crflodiona 16

Table showing effect of washing and pnlping <mi viscosity

of 161

Colloid 161

CoUoidization Tl

Colloids, acoelera.t«d 190

Colldda, compound, containing accderatore, table showing

ballistic efficiMieies of 167

Pure, table showing ballistjc efBciencies of 167

CombustitHi, CMnpIete 173

Of grains. 170

Of powder. 110

Complete combustion 173

Composite powders 179

. Cordite 166

Cotton, friable. 7

NitratiiMi of 127

B«seaTchea upon nitration of 81

Definitions fi

D,g,t,.?<i I,, Google

Deterrento 166

Diititro-methiine, explosive propertiee of 112

Ether as a solvent 55

Btber-elcobid aa a solvit 51, 55

Explosives, aTnmonium compounds as materiala for 109

Benzol derivatives as materials for 121

Hydrocarbons as materials for 109

Tables showing composition and ballistic properties of. 184, 1S6

Friable cottons , 7, 16

Gaaes, calculating volume evolved 99

Evolved by ballistite 117

Evdved by black powder 100

Evolved by browo powder 101

Evolved b^ nitro-oellulose 102

Evolved by nitroform 113

Evolved by nitroglycerin 101, 124

Evolved by nitrohydric acid 109

Evolved by pentanitro-eelluli»e 102

Evolved by pyrocollodion 105

Evolved by pyroxylin- 122

Evolved by tetranitro-cellulose 103

Evolved by trinitro-celluloae 102

Gun-cotton 7, 12, 102

Discovery of. 1

Table showing effect of pulping on 151

Table showing eSeot of washing on i 1.'>1

Gun-cottons 10

Hydration 75

Hydrocarbons, as materials for explosives 109

Hydrocellulose

Amorphous 60

Mercerization 47, 71

MoQoaitr»-merthane, exidosive jvoperties of 112

Multi-<Aiarge principle 102

Nitration 5, 71

Experimento in 134, 140, 141

Higher limit of decree of 91

Of cotton 127

Of cotton, researches upon 81

D,g,t,.?<l I,, Google

198

NitT»Uon, to-ble showing reaults of, for different periods oi

time 137, 142, 145

Temperature in 35, 36

Nitro-c«41ulo»e S, 161

Composition of M

Decomposition-products of ISO

Formula of B4

Ga.ses evolved by 102

Insoluble 5

Of bigh nitration 6

Of low nitration 6

Of mean nitration S

Soluble S

Nitro-cellulo«es, properties of 95

Solubility of, in the crfd 43

Nitroform, explosive properties of ]12

Gases evolved by 113

Nitrogen dioxide, table allowing yield of, in relation to com-
position of acid l>atli 132

Yoiume disengaged per gram of cellulose nitrates 12B

Nitro-glycerin 116

Decomposition-products of ISO

Gases erolved by 101

Qos volume devdoped by 124

In BmokelesB powderd 182

Kitro-bydrocellulose 6

Insoluble 7

Of high nitratiMi 6

Of mean uitratlMi 6

Of low nitration 6

Soluble 7

Solubility at freezing temperature 41, 42

Solutions 38

Nitro-hydrocelluloees^ eoDstitution of 34

Nitro-mannite 116, 118

Nomenclature 4

Oxygen- carriers 32

Pentanitro-cellulose, gascA evolved l^ 102

Polymerization 71

Powder, blaclc, gases evolved by 100

Coooa (brown), gases evolved by iOX

D,g,t,.?<i I,, Google

Powder, pjroxj'lin 126

Smokelew, devdopment of 166

Smokelew, origin of 1

Smolieless, ammonium nitrate In 122

Bmokeless, cellulote as a baae for 126

SmiAeless, nitro-glycerin in 182

Smokeleaa, pyrocellulose as a. liase for 175

Smokeless, pyrocoUodirai as a. base for 97, 125

Powders, colloid 23

Composite 179

Table showing qaalities of 168

Table showing quantity of nitro-caTrierB in certain 183

Propulaive effect, attainmeDt of maximum 169

PjTocellulose 7

Adaptation for smokelew powders 176

Solubility in the cold 43

PyrocollodioD 97

Ab a base for smokeless powders 129

Oases evolved by IDS

Smokeless powders from 97

Pyroxylin 7

Gas volume developed by 122

Powder 126

^roxylin and nitro-naphthalin 122

Pyroxylin and picric acid 122

Smokeless powder, development of 166

Origin of. I

Smokeless powders, anuntmium nitrate in 122

Cellulose as a base for 125

Nitrb^glyeerin in 182

pyrocdluloee as « bane for 176

Pyrocollodion as a base for. 07, 126

Solubility, temperature in relation to 41, 44

Solution, sction of cold in accelerating 61

Table diowing action of nitric Acid mixtures, end results 83

Showing action of sulpho-nitrio add and mixtures, and

results 8T

Showing ballistic efBciencies of pure cidloids and com-
pound colloids containing accrierators 167

Showing composition uid' ballistic jvoperties of explo-

uvea 184, IM

D,g,t,.?<i I,, Google

Table showing composition of acid bath in relation to yidd

of nitrogen dio:Lide 132

lowing effect of temperature during dipping and reac-
tion 149

Showing effect of pulping on gnn-cotton 161

Showing effect of washing on gun-cotton 161

Showing effect of washing and pulping oa the viscositj of

coIlodiooB 161

Showing qualities of powders 168

Showing quantity of nitro-carrier in certain powders. 1S3

Showing results of nitration for different periods of time.

137, 142, 145

Temperaiture, in nitration 3G, 30

In relation to Bolubility 41, 44

Tkble showing effect of, durii^ dipping and reaction 149

Tetronitro^elluloBe, gaees evolved by 103

Tetranitro-methane, exploeive properties of 113

Theory of cellulose molecule 37

Trinitro-methane, explomre properties of 112

Viscosity 27

Of cdlodlons, table showing effect of washing and pulping

n,<i-^f^:>yG00glc

SHORT-TITLE CATALOGUE

PUBLICATIONS

OP

JOHN WILEY & SONS,

New York.
Lohdoh: chapman & HALL, Limited. .

ARRANGED UNDER SUBJECTS.

D«crtpti>R ciruulara seat on appllcaUon.

Books marked with an asterisk are sold at net prices oDly.

All books are bound In clotb unless otherwise slated.

AGRICULTURE.

f Animals —

Arinebf 'a HaDusl of Catlle Feeding ISmo, (1 75

Budd and Hansen, AmerlcHn Horticullure Mauiial.. (in prcM.)

Downing'e Fruit and Fruil: Trees 8vo, 5 00

Qrotenfelt's The Piinclples of Modern Dairy Practice. (Woll.)

13dio, 2 00

Kemp's Landscape Gardening 12mo, 3 60

Haynard'a Landscape Gardening 13mo, 1 50

Bteel's Treatise on tbe Diseases of the Dog 8vo, 3 50

'• Treatise on tlie Diseases of tlie Ox 8vo, 6 00

Btockbridge's Roclis and Soils 8vo, 3 50

Woll's Haadbook for Farmers and Dairymen 12ino, 1 50

ARCHITECTURE.

Br iLD I HG — C ABPEMTRY— Stairs— Ventilatiok— Law, Etc.

Berg's Buildings and Structures of American Riiilroads.. 5 GO

Blrkmire's American Theatres— Planning and Construction. 8to, 3 00

" Architectural Iron and Steel 8vo, 8 50

" Compound Riveted Gii'ders 8vo, 3 00

" Skeleton Constractitw id Buildings . , , 8to, S 00

1 Coogk

BIrkmlre'a Planning and Cousi I'uction of HIgli Office Buildings.

Bi'igga' Modern Am. School Building

Carpenter's Heating nod Veutilating oF Biilldlnga Sto,

Preltag'a Architectural Engineering

The Pireprooflng of Steel Buildioga 870,

Gerhard's Sanitary House Inspection 16ino,

" Theatre Fires and Panics ISmo,

Hatfield's American House Carpenter

Holly's Carpe nice and Joiuer ISnio,

Kidder's Architect and Builder's Pocket-book. . . I6mo,

Merrill's Stones for Building and Decoraiiou

Monckton's Slair Buildiog — Wood, Irou, and Stone 4to,

Wait's Engineering and Aichitcclurul Jurisprudence.

Worcester's Small Hospitals — Establish uient and Haiulenancc,
including Atkinson's Suggestions for Hospital Archi-
tecture ISlBO,

•World's Columbian Exposition of 1893 Large 4lo,

ARMY, NAVY, Etc.
Military Enginkerikg— Oiidnabc£— Law, Etc.

•Bruft's Ordnance and Gunnery 8to,

Chase's Screw Propellers 8vo,

Cionkhile's Gunnery for Non-com. Offlcei-s 32nio, morocco,

•Davis's Tieatlse on Military Law 8vo,

• " Elements of Law 8to,

De Brack's Cavalry Outpost Duties. (Carr.) 33mo,

DielK's Soldier's First Aid 16mo,

•Dredge's Modern French Artillery Large 4to, half morocco,

• " Record of the Trauspojliiliou Exhibits Building,

World's Columbian Eiposition of 1893..4to, half morocco,
Durand's Resistance and Propulsion of Ships 8vo,

• Fiebeger's Field Fortification, including Military Bridges,

Demoiitious, Encampments and Communications.

Large 13mo,
Dyer's Light Artillery 12mo,

Hoffs NaTBl Tactics 8to, (1 60

•lagalU'sBalllHtic Tables 8to. 1 50'

" Handbook of Problems Id Direct Fire 8vo, 4 00

Uuhau'sFermaneutFortificalioiia. (MeTcur.).8<ro, lialf morocco, 7 90

• Mercur'a Attack ot Fortified Places lamo, i 00

• " Elemenia of the Art tif War 8vo, 4 00

Metcalfe's Ordnance and Gunnery 12uio, with Alias, 6 00

Murray's A Manual for Cuurts-Msrlial IGmo, morocco, 1 SO

" Infantry Br[ll RegulatJODB adapted to the Springfield

Kifle, Caliber .45 33mo, paper, 10

•Phelps's Practical Marine Surveying 8vo, S 60

Powell's Army Officer's Exatnioer 13mo, 4 00

Sliarpe's Subsisting Armies 33mo, morocco, 1 GO

WUeeler's Siege Operations 8vo, 2 00

Winthiop's Abridgmenl of Military Law 12n]o, 3 GO

Woodhull's Notes on Military Hygiene lemo, 1 SO

Young's Simple Elements ot Navigation ISmo, morocco, 2 00

" " " " " first edition 1 00

ASSAYINQ.

Smbltino— Obe Drehbinq— Alloys, Etc.

Fletcber's Quant. Assaying with the Blowpipe.. 16mo, morocco, 1 SO

Furman's Practical Assaying Svo, 8 00

Kunhardt's Ore Dressing 8vo, 1 60

Miller's Manual of Assaying 12mo, 1 00

O'Driscoirs Treatment of Gold Ores 8vo, 2 00

BIckettsuud Miller's Notes ou Assaying 8ro, S 00

Thurstou's Alloys, Brasses, and Bronzes 8vo, 2 50

Wilson's Cyanide Processes 12mo, 1 60

The OLlorination Process 12mo, 1 SO

ASTRONOMY.
Pbactical, Thboretical, and Dbbckittitb.

Craig's Azimuth 4to, 3 50

Doollttle's Practical Astronomy 8vo, 4 00

Gore's Elements of Geodesy 6to, 2 50

Hayford'sTest-hookot Geodetic Astronomy 8vo. 8 00

'Micbie and Harlow's Pivctical Astronomy 8vo, 3 00

• White's Theoi'etical and Descriptive Astronomy ISmo, 2 00

BOTANY.

Gardekino fob Ladibb. Etc.

BaldwIn'B Orchids of New England Small 8to, (1 BO

Tboro£'B Stnictunl Botany 16mo, 3 35

Weatermaler'a Oeneral Botany. (Schneider.) 8vo, 3 00

BRIDGES, ROOFS, Etc.

Camtilktbr— Draw— High w a »— ScaPBNBioN .

(See alto 'EsaitiEsmsa, p. T.)

Boiler's Highway Bridges 8to, S 00

• " The Thames River Bridge 4to, paper, 5 00

Burr's Stresses in Bridges 8vo, 3 50

Crehore's Mechanics of the Qirder 8vo, 6 00

Dredge's Thames Bridges 7 parts, per part, 1 25

Du Bois's Stresses in Framed Structures Small 4lo, 10 00

Foster's Wooden Trestle Bridges 4to, 6 00

Greene's Arches in Wood, etc 8vo, 3 50

Bridge Trusses 8vo, 3 ISO

Boof Trusses Svo, 1 25

Howe's Treatise ou Arches 8to, 4 00

Johnson's Modem Framed Structuree Small 4to, 10 OO

aieiriman & Jncoby's Text- book of Roofs and Bridges.

Part I.. Stresses 8vo, 8 60

Uerrlman & Jacoby's Tex (-book of Roofs and Bridges.

Part II., Graphic Statics Svo, 3 60

Merriman & Jacoby's Text-book of Roofs and Bridges.

Part III.. Bridge Design Svo, 2 60

Merriman & Jacoby's Text-book of Roofs and Bridges,

Part lY., Continuous, Draw, Cantilever, Suspension, and

Arched Bridges 8vo, 3 50

• Morisou's The Memphis Bridge Oblong 4lo, 10 00

Wuddell'slron Highway Bridges 8vo, 4 00

" De Poutibua (a Pocket-book for Bridge Engineers).

lOmo, morocco, 3 00

Specifications for Steel Bridges 13mo, 1 3fi

Wood's Construcliou of Bridges and Roofs Svo, 3 00

Wright's Designing of Draw Spans. Paris I. and II.. Svo, each 3 GO

" " " " *' Complete .Sto, 3 60

4 C.OOi}]e

CHEMISTRV— BIOUMV-PHARMACV— SANITAkVSaENCE.

QuALITATlTe— Ql

-OBeANic— Ikoboanic, Etc.

Adriance's Laboratory Calculation a. ISrao,

Allen's Tables Tor Iron Analysis 8vo,

Austeu's Notes for Chemical Students 13mo,

BollOD's Student's Guide la Quaulitative Analysis 8tci,

Boltwood's Elemenlaiy Electro Chemistry (In the preu.)

Classen's Analysis by Blectrolysis. (HerrickandBoltwood.)-8vo,

Oobu's Indicators and Teat-papers ISmo

Cmfts's Qoalilative Analysis. (Schaeffer.) 13mo,

Daveuport's Statistical Methods with Special Reference to Bio-
logical Variations 12ino, morocco,

Drechsel's Cliemical Bcactiona. (Merrill.) ISmo,

£rdinaDn's lotroductinti to Chemical Preparations. (Duulap.)
12mo,

Freseniua's Quantitative Chemical Analysis. {Allen.)

' ' Qualitative " " (Johnson.)

(Wells.) Trans.

16th German Edition 8vo,

Fuertes's Water and Public Health 12mo,

Gill's Oas and Fuel Analysis 12mo,

Hammarsten's Physiological Cbemislrj. (Maudel.)

Helm's Principles of Mathematical Chemistry. (Morgan). 13mo,

Hopkins' Oil -Chemist's Hand-book 8vo,

Ladd's Quantitative Chemical Analysis 12mo,

Landauer's Spectrum Aniilysls. (Tingle.)

Lob's Electrolysis and Eiectrosyn thesis of Organic Compounds.

(Lorcuz.) 12mo,

Htndel's Blo-chemlcal Laboratory ]

Mason's Water-supply 8vo,

" Examination of Water IStno,

Meyer's Radicles in Carbon Compounds. (Tingle.) ]

Mixter's Elementary Text-book of Chemistry 12mo,

Morgan's The Theory of Solutions and its Results 12mo.

" Elemeuls of Physical Chemistry ]

Nichols's Watei-'.upply (Chemical and Sanitary),

O'Briue's Laboratory Guide to Chemical Analysis.

Pinner's Organic Chemistry. (Auslen.) 12mo,

Poole's Calorific Power of Fuels 8vo,

Ricbards'sCost of Living as Modified by Sanitary Science.. 13mo.

*' and Woodman's Air, Water, and Food 8'

Ricketta and Russell's Notes on Inorganic Chemistry (Ni

metallic) Oblong 8vo, moroci

Rideat's Sewage and the Bacterial Puriflcallon of Sewage.. .8vo,

RuddinULn'i Incompatibililies in PrescriptioDS 8vo,

Hchimprt Volumelric Analygis .12mo,

Spencer's Sugar Maoufacturer's Handbook ISmo. morocco,

** Handbook for ChemiaU of Beet Sugar Houses.
I61D0, morocco,

Stockbridge's Rocks fttid Soils 8vo,

• Tillman's Descriptive Qeneral Chemistry 8to,

Van Deventer's Physical Chemistry for Beginners, (Boltwood.)
12mo,

Welb's Inorganic Qualitative Analysis 12mo,

" LslwratoiT Guide in Qualitative Chemical Analysia.
8vo,

Whipple's Microscopy of Drinking-water Svo,

Wlechmann's Chemical Lecture Notes I2mo,

Sugar Analysis Small 8vo,

Wulllng'a Inorganic PLar, and Med. Chemistry ISmo,

«3 00
3 SO
a 00

800
3 00
8 00

I Elbmbktast — Gkometricai. — Msckahtcal — Topographioal.

Hill's Shades and Shadows nod Perspective 8vo, 3

MacCord's Descriptive Geometry Svo, 8

EInematica 8vo, 5

" Mechanical Drawing Svo, 4 C

Mahnn 'a Industrial Drawing. (Thompson.) 3vols.,6vo, 8 G

Reed's TopogiaphicAl Drawing. {H. A.) 4to, 6

Reld's A Course in Mechanical Drawing 8vo. S G

" Mechanical Drawing and Elementary Machine Design.

Svo. 8

Smith's Topographical Drawing. {MacmlUan.) Svo, 3 B

Warren's Descriptive Geometry 2 vols., Svo, 8 S

" Drafting la struments 12mo, 1 2

Free-hand Drawing .... 13mo, 1

" Linear Perspective 12mo, 10

" Machine Construction 2 vols., Svo, 7 B

Plane Problems 12rao, 1 2

Primary Geometry 12ino, 7

" Problems and Theorems 8vo, 2 6

" Projection Drawing 12mo, 1 8

" Shades and Shadows Svo, 8

Stereotomy— St one- cutting. 6vo, 2 G

Whelpley's Letter Engraving 13mo,

Wilson's Free-hand Perspective 8to,

in

(If

ELECTRICITY AND MAGNETISM.

Illumination— B atteries— Ph tsics-Railwayb.
Anthony and Bracketfa Text-book of Physics. (Magie.) Small

8vo, I

Anthony's Theory of Electrical llpasurecneiita 12mo,

Barker's Deep-sea Soundings 8to,

Benjamin's Voltaic Cell fivo,

" Hislory of Electricity 8vo,

Classen's Analysis by Electrolysis. iHcnick null Boltwood }8vo,
Crehore and Squier's Experimeuls wiili a New Polarizing Photo-
Chronograph 8vo,

Dawison's Electric Railways and Tramways. Small, 4lo. half

" " Engiaeering " and Electric Traction Pocket-book. I6mo,

•Dredge's Electric Illumiuations 3 vols., 4to, half n

Yol. II 4(0, 7 50

Gilbert'a De mngiiete. (Mottelay.) 8to, 3 50

Hoi man's Precision of Measuremeula 8vo, 2 00

" Telescope-mirror- scale Method Large 8to, 75

LCb'B Electi-olysis and El cct rosy n thesis of Organic Compounds.

(Loreoz.) ISmo, 1 00

•Michie's Wave Motion Relating to Sound and Light 8vo, 4 00

Morgan's The Theory of Solutions and its Results 12mo, 1 00

Niaudel's Electric Batteries (Fishback.) 12nio, 3 M

•Parslall & Hobart Eleclric Generators. Small 4lo, half mor.. 10 00

Pratt and Alden's Street-railway Rnad-beds 8vo, 3 00

Reagan's Steam and Electric Locomoiives 13mo, 3 00

Thuiaton's Stationary Sleam Engines for Electric Lighting Pur-
poses 8to, 3 M

•Tillman's Heat 8vo. 1 BO

Tory & Pitcher's Laboratory Physics {In prut)

ENaiNEERINa

Civil — Mkchanical— Sanitart, Etc.

(See alto Bhidoes, p. 4 ; Hf DnAULics. p. 9 ; Matbrials
aiNEERiNO, p. 10; Mechanics and Machinery, p. 13
Enoinbs and Boilers, p. 14.)

Baker's Masonry Construction .,..,... 8tc

Surveying Instrnments 13mo, 3 00

Black's U. S. Public Works Oblong 4to, 5 00

Brooks's Street-railway Location 16mo, morocco, 1 50

Bulla's Civil Engineers* Field Book lOmo, morocco, 2 50

Byrne's Highway Construclion 8vo, 5 00

7 C.OiwIc

Byrne's loBpection ot Malerkla aad WorkmaDsliIp Idmo,

Carpenter's ExperimeDtsl EnglDeering 8to,

Cburcb's HecbsDicsof EngiDecriug — Solids and Fluids 8to,

" Notes KDil Exumptea in Mechanics

Crandftll's Earthwork Tables

" The Transition Curre 16mo,

'Dredge's Peon. Railroad Const ruction, etc. Large

half morocco, $10; paper,

* Drinker's Tunnelling Ito, half

Eissler's Explosives— Nitroglycerine and Dynamite 8vo,

Frizell'B Water Power

Folwell'B Sewerage

" Water-supply Eugfneeritig.

Fowler's Coffer-dam Process for Piers

Qerbard's Sanitary House Inspection 12dio,

Godwin's Railroad Engineer's Field-book l«nio, morocco.

Gore's Elementaot Geodesy

Howard's Transition Curve Field-book 16mo,

Howe's Retaining Walls (New Edition.) ' 12mo,

Hudson's Excavation Tables. Vol, II

Ilulton's Mechanical Engineering of Power Plants.

" Heat and Heat Engines 8ro,

Johnson's Materials of CoDStruclion Large 8vo,

" Theory and Practice of Surveying i

Kent's Mechanical Engineer's Pocket-book I6mo,

Eiersted's Sewage Disposal

Mahan's Civil Engineering. (Wood.)

Merriman and Brook's Handbook for Surveyors. . . .16mo.

Merriman's Precise Surveying and Geodesy

" Sanitary Engineering

Nagle's Manual for Railroad Engineers 16mo, morocco,

Ogdeo's Sewer Design 12mo,

Patlou'a Civil Engineering 8vo, half morocco,

Palton'a Foundations

Phil brick's Field Manual for Engineers ]6mo,

Pratt and Aldcn's Street-railway Road-beds.

Rockwell's Roads and Pavements in France ISmo,

Schuyler's Reservoirs for Irrigation Large 8to. {In preu.

Searles's Field Engineering 16mo,

Railroad Spiral 16mo,

Siebert and Biggin's Modern Stone Ciitling and Masonry. . .8vo,

Smart's Engineering Laboratory Practice ISmo,

Smith's Wire Manufacture and Uses Small 4to,

Spalding's Roads and Pavements .13mo,

" Hydraulic Cement ISmo,

Taylor's PriBmoidal Formulas aud Earthwork 8to, |1 60

TburttoD's Materials of CoDstructioD 6to, S OO

TilboD's Street PaTemeDU and Paring Hatetials 8to, i 00

• Trautwine's Civil Engineer's Pocket-book 16mo. morocco, S 00

* " CroBa-Bection Sheet, 35

* " Eic&vatlonB and Embankmenls 8to, S OO

• " Laying Out Curves 13mo, morocco, 2 50

Waddell's De Pontibus (A Pocket-book for Bridge EngioeersJ.

ICino, morocco, 8 00

Wait's Engiueeriog and Archilectural Jurisprudence 8to, 6 00

Sheep, 60

" Law oF Field Operation in EngioeerlDg, etc. 8ro, 5 00

Sheep, 5 50

Warren's Slereotomy — Stone-cutting 8vo, 3 50

Webb's Engineering Instruments. New Edition. 1 6mo, morocco, 1 ZS

Bailroad Construction 8vo, 4 00

Wegmann's Construction of Masonry Dams 4to, 5 00

Wellington's Location of Rallnays Small 8to, 5 00

Wheeler's Civil Engineering 8vo, 4 00

Wilson's Topographical Surveying 8vo, 8 50

Wolff's Windmill as a Prime Mover 8vo, 8 00

HYDRAULICS.

Water- WHKKL8— Win DM iLi-s—SicnvicE Pipb— Dkaibaob, Etc.
(See alMo Enoihebhino, p. 7.)
Bazin's Experiments upon the Contraction of the Liquid Vein.

(Trautwine. ) 8vo, 2 00

Bovey'B Treatise on Hydraulics 8vo, 4 00

Coffin's Graphical Solution of HydiauUc Problems I2mo, a 60

Ferret's Treatise on the Winds, Cyclones, and Tornadoes... »vo, 4 00

Folwell's Water Supply Engineering Svo, 4 00

Fuertes's Water and Public Health 12mo, 1 50

OftngulHet * Kutter's Flow of Waler. (Hering & Trautwlne.)

8vo. 4 00

Hazen's Filtration of Public Water Supply 8vo, 8 00

Herscbel's 116 Experiments 8vo, 2 00

Eieraled's Sewage Disposal ISmo, 1 2S

Mason's Water Supply Svo, 6 00

" Examination of Waler 12mo, 1 26

Merriman's Treatise on Hydraulics 8vo, 4 00

Nicliols's Water Supply {Chemical and Sanitary) 8vo, 2 50

Turneaure and Russell's Water-supply {In pre**.)

Wegmann's Water Supply of the Ciiy of New York 4io, 10 00

Welsbach'B HydrauUcs. (Du Bois.) 8vo, S 00

Whipple's Microscopy of Drinking Water Svo,

ocgre

Wilson's trrlgatton Enginceritig

■■ HydniHllc and PlticiT Miiiiiig

Wolffs Windmill as a Prime Mover.

Wood's Theory of Turbinea

LAW.

AncHrracTcitE— En oinekring— Military.
BtLvis's EiemeDta of Law

" Treatise on Military Law

Murray's A Manual for Courls-marliiil ICmo,

Wait's Engineering and Architeotuml Jiirisprmieiici-. .

— woollehs, i
..8to,

" Laws of Field Operation In Engineeriiig.

Winthrop's Abridgment of Mililniy Law I2mo,

MANUFACTURES.
Bon.EKB— Explosives— Iron— Steel —

Allen's Tables for Iron Analysis ,

Beaumont's Woollen and Worsted Hnnufacture ISmo,

Holland's Eucyc I opied in of Founding Terms 12ino,

The Iron Founder ISmo,

" " " '* Supplement ISmo,

Bouvier's Handbook on Oil Painting

Eissler's ExplosiTea, Nilroglyceiine and Dyi

Ford's Boiler Making for Boiler Makei-s

Metcalfe's Cost of Manufactures

Melcalf's Steel— A Manual for Sieel Users j2mo,

• Reisig's Guide to Piece Dyeing

Spencer's Sugar Mauutiicturer's Handbook 16mo,

" Handbook for Cbemists of Beet Sugar Bouses.
16mo,

Thurston's Manual of Steam Boilere

Walke's Lectures on Explosives

West's American Foundry Practice 12mo,

'■ Moulder's Text-boolt 12rao,

Wiechmann's Sugar Analysis Small

Woodbury's Fire Protection of Mills

MATERIALS OF ENOINEERING.

Btrknoth — Elasiicity — Rbsibtance, Etc.
{See alM Eboinbkhing, p. 7.)

Baker's Masonry Construction

Beardslec and Kent's Strength of Wrouglit Iron .,..-..

10 ^■'''

. .ISnio. 3 00
...8vo, 3 00
...8vo, 2 50

6 60
5 00

S 50

2 50

2 00

4 00

1 00

5 00

2 00
25 00

2 00

4 00
2 50
2 60

Bo vey's Strength of Ma teriuls

Burr's KlaaiJclty nod Resistance ot Mnterlals.

Byrne's Highway CoDstructiou

Church's Mechanics ot En^neering— Solids and Fluids . . ,

Du Bois'B Stresses in Framed Structui-es. Small 4to,

Jobnson'a Materials of ConstructioD 8vo,

Lanza's Applied Mechnnlcs

Martens's Testing Materinla. (Henning.) 2 vols.,

Merrill's Stones for Building and DecoratloD

Merriman's Mechanics of Malerials

■' Strength ot Materials 13mo,

Patton's Treatise on FoundatioDS 8vo,

Rockwell's Roads and Pavemenls iu France 12nio,

Spalding's Roads and Pavements 12mo,

Thurston's Materials of Construction

" Materials of Engineering , 8to1s.,8tO|

Vol. I., Non-metollic 8to,

Vol. II., Iron and Sleel 8vo,

Vol. ni:, Alloys, Brasses, and Bronzes

Wood's Resistance of Materials

MATHEMATICS.

C4LC0LDS— Gbombtby — Tbioomohbtbt, Etc.

Baher's Elliptic Functions 8to,

•Boss's Differential Calculus ISmo,

Brigga's Plane Analytical Geometry 12ino,

Chapman's Theory of Equations 12mo,

Comptou's Logaiithmic Computations ; 12mo,

Davis's Introduction to the Logic ot Algebra 9vo,

Halsted's Elements of Geometry 8to,

" Synthetic Geometry 8vo,

Johnson's Curve Tracing ISmo,

" Difterentiol Equations— Onli nary and Partial.

Small 8vo,

" Integral Calculus I2mo,

" " " Unahridged, Small 8vo. {Inpreit.)

■• Least Squares ISmo,

•Ludlow's Logarithmic and Olher Tables. (Buss.) 8»o,

• " Trigonometry with Tables. (Bass.) 8vo,

•Mahnn'3 Descriptive Geometry (Stone Cutting) .8vo.

Merriraan and Woodward's Higher MatliematiCB 8vo,

Meniman'a Method of Least Squnres 8vo,

Rice and Johnson's Dlffe.renlial and Integral Calculus,

3 vols, in 1. small 8vo,
11

lUce t:.:d JohaBon'a DiSereutlul Culculus Small Sru, (S

" AbridgtucDt of DIflereutial Culculus.

Small 8to, 1

Totteu's Metrology 8to, S

Wsrien'B Descriptive Geometry 3 vol*., Svo, 8

" Draftiug luBtrumvDta. 12mo, 1

" Free-band Drawiug ISmo, 1

Linear Perapecti»c 13mo, 1

" Primiiry Geometry ISmo,

" FlaDC Problems 13mo, 1

" Problems and Theorems 8to, S

" Projection Drawing 13mo, 1

Wood's Co-ordinate Geometry , 8to, 2

" Trigonometry 12mo, 1

Wooira Descriptive Geometry Large 8to, S

MECHANICS- MACHINERY.

Text-books and Practicai. Wokis.
{Sm alto BNoisEBniNQ, p. 8.)

Baldwin's Steam Henting for Buildings 13mo, S

Barr's Kinematics of Macbinery 8to, S

Benjamin's Wrinkles and Recipes 13mo, 2

Chord al'a Letters to Mechanics 12mo, 2

Church's Mechauica of Engineering 8to, 6

" Notes and Examples iu Mechanics 870, 2

Crehore's Mechanics of the Girder 8to, 5

Ci-omwe lis Belts und Pulleys ISmo, 1

" Toothed Gearing 12mo, 1

Comptou's First Lessons in Metal Working ISmo, 1

Compton and De Groodt's Speed Lathe ISmo. 1

Dana's Elementary Mechuuics 12mo, ]

Dingey's Machinery Patteni Making 12nio, i

•Dredge's Trans. Exhibits Building, World Exposition.

Large 4to, half morocco, C

Da Bois's Mechanics. Vol. L. Kinematics 8vo, f

Vol. ir.. Statics 8to, 4

Vol. in., Kinetics 8vo, I

FiUgerald's Boston Machinist 18mo, 1

Flather's Dynamometers 13mo, i

Rope Driving I2mo. i

Hall's Car Lubrication 12mo, 1

Holly's Saw niiug 18mo,

Johnson's Theoretical Mechanics. Au Elementary Treatise,
(/n tha preu.)

Jones's Machine Design. Fart I., Kinematics. .Sro, 1

13 CoiVflc

Joaes'a Macbiae Design. Part II., Strength &Dd Proportion of

Machine Parts 8to,

Lanza's Applied Meciutnics 8to,

MacCord's Kinematlca 8yo,

Uenimau'a Mechanics of Materials 8vo,

Metcalfe's Cost of Manufactures 870,

'Michie'a Analytical Mechanics 8vo,

Richards'a Compressed Air 13mo,

Boblnson's Principles of Mechanism 8to,

Smith's Press. working of Metals 8to,

Thurston's Friction and Lost Work 8to,

" The Animal as a Machine .' 12mo,

Warren's Machine Construction 3 vols., 8to,

Weiabach's Hydraulics and Hydraulic Motors. (Du Bois.)..8vo,
" Mechanics of Engineering, Vol. III., Part I.,

Sec. I. (Klein.) 8to,

Weisbach's Meclianics of Engineering. Vol. III., Part I.,

Sec. II. (Klein.) Sto.

Weisbacb's Steam Engines, (Du Bois.) 8to,

Wood's Analytical Mechanics 870,

" Elementary Mechanics ISmo,

" " " Supplement and Key 13mo,

METALLURQV.

Ihon — Gold— S11.TBB — Allots, Etc.

Allen's Tables for Iron Analysis

Egleston's Gold and Mercury Large

Metallurgy of Silver * Large 8vo,

• Keri's Metallurgy— Copper and Iron

• •' ■• Steel, Fuel, etc 8to,

Kunhardt's Ore Dressing In Europe

Metcalf 's Steel— A Manual for Sleel Users 1

O'DriscoU's Treatment of Gold Oi'es

Thurston's Iron and Steei

" Alloys

Wilson's Cyanide Processes 13mo,

MINERALOaV AND MININQ.

Mine Accidents — Ventilation— Ore DRBSBiNa, Btc.

Barringer's Minerals of Commercial Value Oblong morocco.

Beard's Ventilation of Mines 12mo,

Boyd's Resources of South Western Virginia Svo,

" Map of South Western Virginia Pocket-book form,

Brush and Penfield's Determinative Mineralogy. New Ed. Svo,
13

Chester's Catalogue of Hiaersla 8to,

" " '* " Paper,

" DictloDarj of tbe Names of Miuerata 8vo,

Dana's Americaa Locsliiltis of Minemls Large Hvo,

'• Descriptive Mioeralogy (E.8.) Largedvo. half more
" FiiBt Appendix to System of Miueralogy. . . . Laige

" Miueralogy and Petrognipliy, (J. D.) 13mo,

" Minerals and How to Study Tbem. (E. 8.) ISmo,

" Teit-ljooli of Mioeralogy. {E. S.).. .New Edition. 8to,

•DrlQker'sTonuelling, Explosives, Compoiiuda, and Rocli Drills.

4tu, ijalf morocco,

Egleston's Catalogue of Minerals and Syuonyma

Eissicr'a Eiploaives—Nitrosljcerine and Dynamite 8ro,

Busaak'a Rock- Forming Miuei^lB. (Smith.) Small

Ihlaeng's Uauual of Milling

Kunbnrdt's Ore Dressing in Europe 8to,

O'Driscoll'a Treatment ot Gold Ores

• Penfield's Record of Mineral Tests Paper, 8vo,

Rosenbiisch's Microscopical Pbysiograpliy of Minerals aud

Rocks. (Iddiugs.) Svo,

Sawyer's Accidents iu Mines Large 8vo,

Stockbridge's Rocks and Soils

Tillman's Impoi-tant jMinerals aud Rocks Svo,

Walke'a Lectures cu Explosives

Williams's Lithoiogy

WIlBau'sMiue Vcntilatiou ]

" Hydraulic aud Placer Mibing. ..12mo,

$1 3S

50

S 00

1 00

12 50

1 00

2 00
1 SO
4 00

35 00

3 SO

4 00

3 00

4 00
I 50

5 00
7 00
3 SO

3 00

4 00
3 00
1 S5
3 50

STEAM AND ELECTRICAL ENGINES, BOILERS, Etc.

Stationaut—Mahine— Locomotive — Gab Ehbines, Etc.
(Sm also ENOiNiKBiNQ, p. 7.)

Baldwin's Steam Heating for Buildings ISmo, 3 00

Clerk's Qas Eugine SmallSvo, 4 00

Fords Holier Making for Boiler Makers ISuio, 1 00

Heme II way's Indicator Practice ISrao, 3 00

Kaeiiss'a Practice and Theory of the Injector 8vo, 1 50

MacCord's Slide Valve Svo. 3 00

Meyer's Modern Locomotive Coustructlon 4lo, 10 00

Peabodyand Miller's Steam-boilers Svo, 4 00

Peabody's Tables of Saturated Steam 8vo, 1 00

Thermodynamics of the Slenni Engine Svo, G 00

■' Valve Gears for tbe Steam Engine Svo, S 60

Manual of the Steam-engiue ludicator 13mo, 150

Pray's Twenty Years with tbe ludicator Large Svo, 3 60

Pupiu and Oatcrberg's Thermodynamics I3mo, 1 39

Reagan's Bleam and Electric Locomotives 12mo, |3 00

ROulgen's TberinodyDnmtcs. (Dii Boia.) 8vo, 00

Slocloir's Locomotive Ruaniug 12mo, 9 00

Snow's Btcftm-boiler Piactlce 8vo. 8 GO

ThuTStoo's Boiler Explosions 12mo, 1 60

" Engine and Boiler Trials 8vo, 5 00

■' Mwjual of tbe Steom Eugine, Part L, Structure

and Tlieurj 8vo, 6 00

" Manual of the Steam Eugine. Part IL, Design,

Construction, and Operaliou 8vo, 6 00

2 parts, 10 00

Thurston's Philosophy of the Steam Engine 13mo, 75

" Reflectiou on the Motive Power of Heal. (Carnot.)

12mo, 1 SO

" Stntionaiy Steam Engines 8vo, Z 50

" Steatn-boilcr CouBtruclion und Operaliou 8vo, 5 00

Spangler'a Volvo Gears 8vo, 3 50

Wcisboch's Steam Engine, (Du Bois.) 8vo, 6 00

Wbitliam'a Sieam-engioe Design 6vo, 5 00

Wilson's Sleam Boilers. (Fbitber.) 12mo, 2 50

Wood's Therm odjE amies. Heat Motors, etc 8to, 4 OO

TABLES, WBIQHTS, AND MEASURES.

For Actuaries, Chbuists. ENOiNSBns, Mbcuanicb— Mbtrio
Tajjlee, Etc.

Ad riance's Laboratory Calculations ]

Allen's Tables fur Iron AuulysiB

Bixby's Gnipbical Computing Tables S

Comptou's Logarithms ]

CraodiiU'a Kiiilway and Earthwork Tables 8vo,

Egleston's Weights and Measures 18mo,

Fisher's Table of Cubic Yards. Cardboard,

Hudson's Excavaliou Tables. Vol. II

Johnaon'B Stadia and Earthwork Tables

Ludlow's Logarithmic and Other Tables. (Boss.) 1

Totten 'a Metrology 8vo, 3

VENTILATION.

Steam Hbatiho — House Ihsfbction — Hike VKHTiiiATiou.

Baldwin's Steam Heiiting I3mo, 3

Beard's Ventilation of Mines. ISrao, 3

Carpenter's Heating and Ventilating of Buildings 8to, 3

Qerhard's Sanitary House Inspection ISmo, 1

Wilson's Mine Ventilation.- 13nio, 1

15

MISCELLANEOUS PUBUCATIONS.

AIcott'B Oems, Seatiment, Lacgoage Oilt edges, (S 09

- - - a 00

1 50
400
S 60
1 00
1 OO

Davis's Eletnenta of Law.

EmmoD's Geological Guide-book of the Kocky Hountolna. .8to,

Ferrel'a Treatise on tbe Winds Bvo,

Haines's Addresses Delivered before the Am. Ry. A6sii...I3mo,
M<rtt's The Fallacy of the Present Theory of Sound. .8q. lOnio,

Rlcharda's Cost of Living 12mo.

RicketU's History of Kenaeelaer Fotytecbnic Institute 8vo, 8 00

Rotherham's The New Testament Crilicaliy Emphasized.

ISmo, 1 50
" The Emphasized New Test, A new translation.

Large 8to, 3 00

ToUen's An Important Question in Metrology 8vo, 2 60

• Wiley's Tosemite, Alaska, and Yellowstone 4to, 8 00

HEBREW AND CHALDEE 'reXT-BOOKS.

FoK Schools and Thkological SuMiNARiBa,

Qesentiis's Hebrew and Chaldee Lexicon to Old Testament.

(Tregellea.) Small 4to, half morocco, 5 00

Green's Elementary Hebrew Grammar ISmo, 1 2S

" Grammar of the Hebrew Language (New Edition). 6vo, 8 00

" Hebrew Chrestomathy 8vo, 3 00

Letteris's Hebrew Bible (Masaoretic Notes in English).

8to, arabesque, S S6

MEDICAL.

Hammarsten's Fhyaloluglcnl Chemistry. (Handel.) Svo, 4 00

Mott's Composition, Digestibility, and Nutritive Value of Food.

Large mounted chart, 1 S5

Ruddlman's Incompatibilities in Prescriptions Svo, 2 00

' Steel'a Treailse on the Diseases of the Ox 8to, « 00

Treatise on the Diaeases of the Dog Svo, 8 BO

WoodhuU'a Military Hygiene 16mo, 1 »

Worcester's Small Hospitals — Establishment and Maintenance,
including Atkinson's Suggestions for Hospital Archi-
tecture. 13mo, 1 26

'..>y Google

n,r.^^<i "/Google

I,, Google

D,g,t,.?<i I,, Google

D,g,t,.?<i I,, Google

D,g,t,.?<i I,, Google

D,g,t,.?<i I,, Google