LIBRARY
OF THE
UNIVERSITY OF CALIFORNIA.
Class
NITRO-EXPLOSIVES
NlTRO-EXPLOSIVES
A PRACTICAL TREATISE
CONCERNING THE
PROPERTIES, MANUFACTURE, AND ANALYSIS OF
NITRATED SUBSTANCES, INCLUDING THE FULMINATES,
SMOKELESS POWDERS, AND CELLULOID
BY
P. GERALD SANFORD, F.I.C., F.C.S.
Public Analyst to the Borough of Penzance; late Consulting Chemist to the Cotton Powder
Company Limited ; and formerly Resident Chemist at the Stowmarket Works
of the New Explosives Company Limited, and the Hayle Works
of the National Explosive Company -Limited
Second B&ttton, IRevisefc an& BnlargeD
NEW YORK
D. VAN NOSTRAND COMPANY
23 MURRAY AND 27 WARREN STREETS
LONDON
CROSBY LOCK WOOD AND SON
1906
^> *^
OF THE
UNIVERSITY J
OF /
PREFACE.
T N compiling the following treatise, my aim has
* been to give a brief but thoroughly practical
account of the properties, manufacture, and methods
of analysis of the various nitro-explosives now so
largely used for mining and blasting purposes and
as propulsive agents ; and it is believed that the
account given of the manufacture of nitro-glycerine
and of the gelatine dynamites will be found more
complete than in any similar work yet published in
this country.
For many of the facts and figures contained in
the chapter on Smokeless Powders I am indebted
to (amongst others) the late Mr J. D. Dougall
and Messrs A. C. Ponsonby and H. M. Chapman,
F.C.S. ; and for details with regard to Roburite
to Messrs H. A. Krohn and W. J. Orsman, F.I.C.
To these gentlemen my cordial thanks are due.
Among the authorities which have been consulted
in the general preparation of the work may be
mentioned the Journals of the Chemical Society,
the Society of Chemical Industry, the United States
VI PREFACE.
Naval Institute, and the Royal Artillery Institution.
I have also referred to several volumes of the
periodical publication Arms and Explosives; to
various pap'ers by Sir Frederick Abel, Bart., F.R.S.,
and General Wardell, R.A., on Gun-Cotton ; to
"Modern Artillery," by Capt. Lloyd, R.N., and
A. G. Hadcock, R.A. ; to the late Colonel Cundill's
" Dictionary of Explosives " ; as well as to the
works of Messrs Eissler, Berthelot, and others.
The illustrations have been prepared chiefly
from my own drawings. A few, however, have
been taken (by permission) from the pages of Arms
and Explosives, or from other sources which are
acknowledged in the text.
P. G. S.
THE LABORATORY,
20 CULLUM STREET, E.G.
May 1896.
UNIVERSITY
OF
PREFACE TO THE SECOND EDITION.
IN the preparation of the Second Edition of this
work, I have chiefly made use of the current
technical journals, especially of the Journal of the
Society of Chemical Industry. The source of my
information has in every case been acknowledged.
I am also indebted to several manufacturers of
explosives for information respecting their special
products— among others the New Explosives Com-
pany Ltd. ; Messrs Curtis's and Harvey Ltd. ; The
Schultze Gunpowder Company Ltd. ; and Mr W. D.
Borland, F.I.C., of the E. C. Powder Company Ltd.
To my friend Mr A. Stanley Fox, F.C.S., of
Faversham, my best thanks are also due for his
help in many departments, and his kindness in
pointing out several references.
The chapter on Smokeless Powders has been
considerably enlarged and (as far as possible) brought
up to date ; but it has not always been possible to
give the process of manufacture or even the com-
position, as these details have not, in several cases,
been made public.
P. GERALD SANFORD.
LONDON, June 1906.
17457?
TABLE OF CONTENTS.
CHAPTER L— INTRODUCTION
PAGES
The Nitro- Explosives — Substances that have been Nitrated — The
Danger Area — Systems of Professors Lodge, Zenger, and
Melsens for the Protection of Buildings from Lightning, &c. - 1-16
CHAPTER II.— NITRO-GLYCERINE.
Properties of Nitro-Glycerine — Manufacture — Nitration — Separa-
tion—Washing and Filtering — Drying, Storing, &c. — The
Waste Acids — Their Treatment — Nitric Acid Plants - - 17-46
CHAPTER III.-NITRO-CELLULOSE, &c.
Cellulose Properties — Discovery of Gun-Cotton — Properties of
Gun-Cotton — Varieties of Soluble and Insoluble Gun-
Cottons — Manufacture of Gun-Cotton — Dipping and Steep-
ing— Whirling Out the Acid — Washing, Boiling, Pulping,
Compressing — The Waltham Abbey Process — Le Bouchet
Process — Granulation of Gun-Cotton — Collodion-Cotton —
Manufacture — Acid Mixture Used — Cotton Used, &c. —
Nitrated Gun-Cotton — Tonite — Dangers in Manufacture of
Gun-Cotton—Trench's Fire-Extinguishing Compound — Uses
of Collodion-Cotton — Celluloid — Manufacture, &c. — Nitro-
Starch, Nitro-Jute, and Nitro-Mannite - - - - 47-111
CHAPTER IV.— DYNAMITE.
Kieselguhr Dynamite — Classification of Dynamites — Properties
and Efficiency of Ordinary Dynamite — Other forms of
Dynamite — Gelatine and Gelatine Dynamites, Suitable Gun-
Cotton for, and Treatment of— Other Materials Used — Com-
position of Gelignite— Blasting Gelatine — Gelatine Dynamite
— Absorbing Materials — Wood Pulp — Potassium Nitrate, &c.
— Manufacture, &c. — Apparatus Used — The Properties of the
Gelatine Compounds 112-131
X TABLE OF CONTENTS.
PAGES
CHAPTER V.— NITRO-BENZOL, ROBURITE, BELLITE,
PICRIC ACID, &c.
Explosives derived from Benzene — Toluene, Nitro-Benzene, Di-
and Tri-Nitro — Roburite : Properties and Manufacture —
Bellite : Properties, &c. — Securite — Tonite No. 3 — Nitro-
Toluene — Nitro-Naphthalene — Faversham Powder — Ammo-
nite— Electronite — Sprengel's Explosives — Picric Acid —
Picrates — Picric Powders — Melinite — Abel's Mixture —
Brugere's Powders — Tri-nitro-cresol 132-167
THE FULMINATES.
Composition, Formula, Preparation, Danger of, &c. — Detonators :
Sizes, Composition, Manufacture — Fuses, &c. - - - 159-167
CHAPTER VI.— SMOKELESS POWDERS IN
GENERAL.
Cordite— Axite— Ballistite— U.S. Naval Powder— Schultze's E.G.
Powder — Indurite — Vielle Poudre — Walsrode and Cooppal
Powders — Amberite — Troisdorf — B. N. Powder— Wetterin —
Normal. Powder — Maximite — Picric Acid Powders, &c. &c. - 168-196
CHAPTER VII.— ANALYSIS OF EXPLOSIVES.
Kieselguhr Dynamite — Gelatine Compounds — Tonite — Cordite —
Vaseline — Acetone — Scheme for Analysis of Explosives —
Nitro-Cotton — Solubility Test — Non-Nitrated Cotton-
Alkalinity — Ash and Inorganic Matter — Determination of
Nitrogen — Lunge, Champion and Pellet's, Schultze-Tieman,
and Kjeldahl's Methods — Celluloid — Picric Acid and
Picrates — Resinous and Tarry Matters — Sulphuric Acid arid
Hydrochloric Acid and Oxalic Acid — Nitric Acid — Inorganic
Impurities — General Impurities and Adulterations — Potassium
Picrate, &c. — Picrates of the Alkaloids — Analysis of Glycerine
— Residue — Silver Test — Nitration — Total Acid Equivalent
— Neutrality — Free Fatty Acids — Combined Fatty Acids —
Impurities — Oleic Acid — Sodium Chloride— Determination of
Glycerine — Waste Acids — Sodium Nitrate — Mercury Fulmi-
nate— Cap Composition — Table for Correction of Volumes of
Gases, for Temperature and Pressure •• - - - - 197-246
CHAPTER VIII.— FIRING POINT OF EXPLOSIVES,
HEAT TESTS, &c.
Horsley's Apparatus — Table of Firing Points — The Government
Heat Test Apparatus, &c., for Dynamites, Nitro-Glycerine,
Nitro-Cotton, and Smokeless Powders — Guttmann's Heat
Test — Liquefaction and Exudation Tests — Page's Regulator
for Heat Test Apparatus -Specific Gravities of Explosives —
Will's Test for Nitro-Cellulose— Table of Temperature of '
Detonation, Sensitiveness, &c. - - - - - - 247-271
TABLE OF CONTENTS. XI
PAGES
CHAPTER IX.— THE DETERMINATION OF THE
RELATIVE STRENGTH OF EXPLOSIVES.
Effectiveness of an Explosive — High and Low Explosives — Theo-
retical Efficiency — MM. Roux and Sarrau's Results — Abel and
Noble's— Nobel's Ballistic Test— The Mortar— Pressure or
Crusher Gauge — Calculation Volume of Gas Evolved, &c. —
Lead Cylinders — The Foot- Pounds Machine — Noble's Pres-
sure Gauge — Lieut. Walke's Results — Calculation of Pressure
Developed by Dynamite and Gun-Cotton — M'Nab's and
Ristori's Results of Heat Developed by the Explosion of
Various Explosives — Composition of some of the Explosives
in Common Use for Blasting, &c. ..... 272-294
INDEX - - - . - . . - . - . .- '- - - 295-300
LIST OF ILLUSTRATIONS.
FRONTISPIECE — Danger Building showing Protecting Mounds.
1. Section of Nitro-Glycerine Conduit 7
2. Melsens System of Lightning Conductors - - ' - - - 10
3. French System " ' - - - 11
4« & 4#. English Government System - - '* . • -. - 12
5. Upper Portion of Nitrator for Nitro-Glycerine - - 27
6. Small Nitrator ' - - 31
7. Nathan's Nitrator - - - - . - - » - 33
8. Nitro-Glycerine Separator - - 36
9. Nitro-Glycerine Filtering Apparatus - - - - - 37
10. Cotton-Waste Drier - . - . 59
n. Dipping Tank - ... .," ' . . 61
12. Cooling Pits - - - - - - - • ,- - 61
13. Steeping Pot for Gun-Cotton - - - - - .- .- 62
14. Hydro-Extractor or Centrifugal Drier 62
I5#& i5/>. Gun-Cotton Beater 64,65
i6a. Poacher for Pulping Gun-Cotton 65
idb. Plan of same 66
\6c. Another form of Poacher * x 66
17 & 1 8. Compressed Gun-Cotton - 68
19. Hydraulic Press 70
20. Thomson's Apparatus— Elevation 74
21. Elevation Plan - - - - - - - - 75
Xll LIST OF ILLUSTRATIONS.
FIG. PAGES
22. Trench's Safety Cartridge - 89
23. Vessel used in Nitrating Paper 96
24. Cage ditto — White & Schupphaus' Apparatus - - - - 97
25. Do. do. do. 97
26 & 27. Nitrating Pot for Celluloid .... 97
28 & 29. Plunge Tank in Plan and Section - ... 98
30. Messrs Werner, Pfleiderer & Perkins' Mixing Machine - - 124
31. M 'Roberts' Mixing Machine for Blasting Gelatine - - 125
32. Plan of same - 127
33. Cartridge Machine for Gelatines 128
34. Cartridge fitted with Fuse and Detonator 166
35. Gun-Cotton Primer - 166
36. Electric Firing Apparatus - ------ 167
37. Metal Drum for Winding Cordite 171
38. Ten-Stranding - - - - 171
39. Curve showing relation between Pressures of Cordite and Black
Powder, by Professor Vivian Lewes - - - - 175
40. Marshall's Apparatus for Moisture in Cordite ... 207
41. Lunge's Nitrometer 220
42. Modified do. 222
43. Horn's Nitrometer 222
44. Schultze-Tieman Apparatus for Determination of Nitrogen in
Gun-Cotton - 225
45. Decomposition Flask for Schultze-Tieman Method - - - 226
46. Abel's Heat Test Apparatus 249
47. Apparatus for Separation of Nitro-Glycerine from Dynamite - 252
48. Test Tube arranged for Heat Test 252
49. Page's Regulator 260
50. Do. showing Bye-Pass and Cut-off Arrangement - 260
51. Will's Apparatus ------ 263
52 & 53. Curves obtained 266-267
54. Dynamite Mortar - - 275
55. Quinan's Pressure Gauge 278
56. Steel Punch and Lead Cylinder for Use with Pressure Gauge 279
57. Micrometer Calipers for Measuring Thickness of Lead Cylinders 280
58. Section of Lead Cylinders before and after Explosion - - - 281
59. Noble's Pressure Gauge - - ', 282
60. Crusher Gauge - - . - -- 284
* 'OF THE
UNIVERSITY
OF
NITRO-EXPLOSIVES.
CHAPTER I.
INTRODUCTORY.
The Nitro-Explosives — Substances that have been Nitrated — The Danger Area
— Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.
THE manufacture of the various nitro-explosives has made
great advances during late years, and the various forms of
nitro-compounds are gradually replacing the older forms of
explosives, both for blasting purposes and- also for propul-
sive agents, under the form of smokeless powders. The
nitro-explosives belong to the so-called High Explosives,
and may be defined as any chemical compound possessed
of explosive properties, or capable of combining with
metals to form an explosive compound, which is produced
by the chemical action of nitric acid, either alone or mixed
with sulphuric acid, upon any carbonaceous substance,
whether such compound is mechanically mixed with other
substances or not.*
The number of compounds and mixtures included under
this definition is very large, and they are of very different
chemical composition. Among the substances that have
been nitrated are : — Cellulose, under various forms, e.g.,
* Definition given in Order of Council, No. i, Explosives Act, 1875.
A
2 NITRO-EXPLOSIVES.
cotton, lignin, &c. ; glycerine, benzene, starch, jute, sugar,
phenol, wood, straw, and even such substances as treacle
and horse-dung. Some of these are not made upon the
large scale, others are but little used. Those of most im-
portance are nitro - glycerine and nitro - cellulose. The
former enters into the composition of all dynamites, and
several smokeless powders ; and the second includes gun-
cotton, collodion-cotton, nitrated wood, and the majority
of the smokeless powders, which consist generally of
nitro-cotton, nitro-lignin, nitro-jute, &c. &c., together with
metallic nitrates, or nitro-glycerine.
The nitro-explosives consist generally of some organic
substance in which the NO2 group, known as nitryl, has
been substituted in place of hydrogen.
TOR
Thus in glycerine, C3H5JOH, which is a tri-hydric
[OH
alcohol, and which occurs very widely distributed as the
alcoholic or basic constituent of fats, the hydrogen atoms
are replaced by the NO9 group, to form the highly explo-
sive compound, mtro-glycerine. If one atom only is thus
fONO2
displaced, the mono-nitrate is formed thus, C8H6vOH ;
[OH
and if the three atoms are displaced, C3H5(ONO2)3, or the
tri-nitrate, is formed, which is commercial nitro-glycerine.
Another class, the nitro-celluloses, are formed from
cellulose, C6H10O5, which forms the groundwork of all
vegetable tissues. Cellulose has some of the properties of
the alcohols, and forms ethereal salts when treated with
nitric and sulphuric acids. The hexa-nitrate, or gun-cotton,
has the formula, C12H14O4(ONO2)6; and collodion-cotton,
pyroxylin, &c., form the lower nitrates, i.e., the tetra- and
penta-nitrates. These last are soluble in various solvents,
such as ether-alcohol and nitro-glycerine, in which the
NITRO-COMPOUNDS. 3
hexa-nitrate is insoluble. They all dissolve, however, in
acetone and acetic ether.
The solution of the soluble varieties in ether-alcohol is
known as collodion, which finds many applications in the
arts. The hydrocarbon benzene, C6H6, prepared from the
light oil obtained from coal-tar, when nitrated forms nitro-
benzenes, such as mono-nitro-benzene, CGH5NO2, and di-
nitro-benzene, C6H4(NO2)2, in which one and two atoms are
replaced by the NO2 group. The latter of these com-
pounds is used as an explosive, and enters into the compo-
sition of such well-known explosives as roburite, &c. The
presence of nitro groups in a substance increases the
difficulty of further nitration, and in any case not more
than three nitro groups can be introduced into an aromatic
compound, or the phenols. All aromatic compounds with
the general formula, C6H4X2, give, however, three series.
They are called ortho, meta, or para compounds, depending
upon the position of NO2 groups introduced.
Certain regularities have been observed in the formation
of nitro-compounds. If, for example, a substance contains
alkyl or hydroxyl groups, large quantities of the para com-
pound are obtained, and very little of. the ortho. The
substitution takes place, however, almost entirely in the
meta position, if a nitro, carboxyl, or aldehyde group be
present. Ordinary phenol, C6H5.OH, gives para- and
ortho-nitro-phenol ; toluene gives para- and ortho-nitro-
toluene ; but nitro-benzene forms meta-di-nitro-benzene
and benzoic acid, meta-nitro-benzoic acid.*
If the graphic formula of benzene be represented thus
(No. i), then the positions I and 2 represent the ortho, I
and 3 the meta, and I and 4 the para compounds. When the
body phenol, C6H5.OH, is nitrated, a compound is formed
known as tri-nitro-phenol, or picric acid, CGH2(NO2)3OH,
which is used very extensively as an explosive, both as
* " Organic Chemistry," Prof, Hjelt. Translated by J. B. Tingle,
Ph.D.
4 NITRO-EXPLOSIVES.
picric acid and in the form of picrates. Another nitro
body that is used as an explosive is nitro-naphthalene,
C10HG(NO2)2, in roburite, securite, and other explosives of
this class. The hexa-nitro-mannite, C6H8(ONO2)6, is formed
H.I
H.C CH.2
H.C CH.3
C E-OJNlT.RO -BENZENE
H.4 N?2.
f\}° I.
by treating a substance known as mannite, C6H8(OH)6, an
alcohol formed by the lactic acid fermentation of sugar and
closely related to the sugars, with nitric and sulphuric acids.
It is a solid substance, and very explosive ; it contains
18.58 per cent, of .nitrogen.
Nitro-starch has also been used for the manufacture of
an explosive. Miihlhauer has described (Ding. Poly. Jour.,
73) ^/-HS) three nitric ethers of starch, the tetra-nitro-
starch, C12H16O6(ONO2)4, the penta- and hexa-nitro-starch.
They are formed by acting upon potato starch dried at
100° C. with a mixture of nitric and sulphuric acids at a
temperature of 20° to 25° C. Rice starch has also been
used in its production. Miihlhauer proposes to use this
body as a smokeless powder, and to nitrate it with the
spent mixed acids from the manufacture of nitre-glycerine.
This substance contains from 10.96 to 11.09 Per cent, of
nitrogen. It is a white substance, very stable and soluble
even in cold nitro-glycerine.
The explosive bodies formed by the nitration of jute
have been studied by Messrs Cross and Bevan, and "also
NITRO-JUTE AND NITRO-STARCII. 5
by Miihlhauer. The former chemists give jute the formula
C12H18O9, and believe that its conversion into a nitro-
compound takes place according to the equation —
This is equivalent to a gain in weight of 44 per cent, for
the tri-nitrate, and 58 per cent, for the tetra-nitrate. The
formation of the tetra-nitrate appears to be the limit of
nitration of jute fibre. Messrs Cross and Bevan say, " In
other words, if we represent the ligno-cellulose molecule
by a C12 formula, it will contain four hydroxyl (OH) groups,
or two less than cellulose similarly represented." It contains
11.5 per cent, of nitrogen. The jute nitrates resemble those
of cellulose, and are in all essential points nitrates of ligno-
cellulose.
Nitro-jute is used in the composition of the well-known
Cooppal Smokeless Powders. Cross and Bevan are of
opinion that there is no very obvious advantage in the use
of lignified textile fibres as raw materials for explosive
nitrates, seeing that a number of raw materials containing
cellulose (chiefly as cotton) can be obtained at from £10
to .£25 a ton, and yield also 150 to 170 per 'cent, of explosive
material when nitrated (whereas jute only gives 154-4 Per
cent), and are in many ways superior to the products
obtained from jute. Nitro-lignin, or nitrated wood, is,
however, largely used in the composition of a good many
of the smokeless powders, such as Schultze's, the Smokeless
Powder Co.'s products, and others.
The Danger Area. — That portion of the works that
is devoted to the actual manufacture or mixing of explosive
material is generally designated by the term " danger area,"
and the buildings erected upon it are spoken of as " danger
buildings." The best material of which to construct these
buildings is of wood, as in the event of an explosion they
will offer less resistance, and will cause much less danger
than brick or stone buildings. When an explosion of
6 NITRO-EXPLOSIVES.
nitro-glycerine or dynamite occurs in one of these buildings,
the sides are generally blown out, and the roof is raised
some considerable height, and finally descends upon the
blown-out sides. If, on the other hand, the same explosion
had occurred in a strong brick or stone building, the walls
of which would offer a much larger resistance, large pieces
of brickwork would probably have been thrown for a
considerable distance, and have caused serious damage to
surrounding buildings.
It is also a very good plan to surround all danger
buildings with mounds of sand or earth, which should be
covered with turf, and of such a height as to be above the
roof of the buildings that they are intended to protect
(see frontispiece).* These mounds are of great value in
confining the force of the explosion, and the sides of the
buildings being thrown against them are prevented from
travelling any distance. In gunpowder works it is not
unusual to surround the danger buildings with trees or
dense underwood instead of mounds. This would be of no
use in checking the force of explosion of the high explosives,
but has been found a very useful precaution in the case of
gunpowder.
In Great Britain it is necessary that all danger buildings
should be a specified distance apart ; a license also must be
obtained. The application for a license must give a plan
(drawn to scale) of the proposed factory or magazine, and
the site, its boundaries, and surroundings, and distance the
building will be from any other buildings or works, &c.,
* At the Eaelen Factory, Belgium, the danger buildings are erected
on a novel plan. They are circular in ground plan and lighted entirely
from the roof by means of a patent glass having wire-netting in it, and
which it is claimed will not let a splinter fall, even if badly cracked.
The mounds are then erected right up against the walls of the building,
exceeding them in height by several metres. For this method of con-
struction it is claimed that the force exerted by an explosion will expand
itself in a vertical direction ("Report on Visits to Certain Explosive
Factories," H.M. Inspectors, 1905).
ARRANGEMENT OF DANGER AREA. 7
also the character, and construction of all the mounds, and
nature of the processes to be carried on in the factory or
building.*
The selection of a site for the danger area requires some
attention. The purpose for which it is required, that is,
the kind of explosive that it is intended to manufacture,
must be taken into consideration. A perfectly level piece
FIG. i. — SECTION OF NITKO-GLYCERINE CONDUIT.
«, lid ; b, lead lining ; c, cinders.
of ground might probably be quite suitable for the purpose
of erecting a factory for the manufacture of gun-cotton or
gunpowder, and such materials, but would be more or less
unsuitable for the manufacture of nitro-glycerine, where a
number of buildings are required to be upon different levels,
in order to allow of the flow of the liquid nitro-glycerine
from one building to another through a system of conduits.
These conduits (Fig. i), which are generally made of wood
and lined with lead, the space between the woodwork and
the lead lining, which is generally some 4 or 5 inches, being
filled with cinders, connect the various buildings, and should
slope gently from one to the other. It is also desirable
that, as far as possible, they should be protected by earth-
work banks, in the same way as the danger buildings
themselves. They should also be provided with covers,
which should be whitewashed in hot weather.
A great deal of attention should be given to these
conduits, and they should be very frequently inspected.
Whenever it is found that a portion of the lead lining
requires repairing, before cutting away the lead it should
* Explosives Act, 38 Viet. ch. 17.
8 NITRO-EX PLOSIVES.
be very carefully washed, for several feet on either side of
the portion that it is intended to remove, with a solution
of caustic soda or potash dissolved in methylated spirit and
water, and afterwards with water alone. This decomposes
the nitro-glycerine forming glycerine and potassium nitrate.
It will be found that the mixed acids attack the lead rather
quickly, forming sulphate and nitrate of lead, but chiefly
the former. It is on this account that it has been proposed
to use pipes made of guttapercha, but the great drawback
to their use is that in the case of anything occurring inside
the pipes, such as the freezing of the nitro-glycerine in
winter, it is more difficult to find it out, and the condition
of the inside cannot be seen, whereas in the case of wooden
conduits it is an easy matter to lift the lids along the whole
length of the conduit.
The buildings which require to be connected by con-
duits are of course those concerned with the manufacture
of nitro-glycerine. These buildings are — (i) The nitrating
house; (2) the separating house; (3) the filter house; (4)
the secondary separator ; (5) the deposit of washings ; (6)
the settling or precipitation house ; and each of these
buildings must be. on a level lower than the preceding one,
in order that the nitro-glycerine or acids may flow easily
from one building to the next. These buildings are, as far
as possible, best placed together, and away from the other
danger buildings, such as the cartridge huts and dynamite
mixing houses, but this is not essential.
All danger buildings should be protected by a light-
ning conductor, or covered with barbed wire, as suggested
by Professor Sir Oliver J. Lodge, F.R.S., Professors Zenger,
of Prague, and Melsens, of Brussels, and everything
possible should be done to keep them as cool as possible
in the summer. With this object they should be made
double, and the intervening space filled with cinders.
The roof also should be kept whitewashed, and the
windows painted over thinly with white paint. A ther-
mometer should be suspended in every house. It is very
PROTECTION OF DANGER BUILDINGS. Q
essential that the floors of all these buildings should be
washed every day before the work-people leave. In case
any nitro-glycerine is spilt upon the floors, after sponging
it up as far as possible, the floor should be washed with
an alcoholic solution of soda or potash to decompose the
nitro-glycerine, which it does according to the equation*—
C3H6(N03)3+ 3KOH = C3H803 + 3KN03.
Every one employed in the buildings should wear list
or sewn leather shoes, which of course must be worn in the
buildings only. The various houses should be connected
by paths laid with cinders, or boarded with planks, and
any loose sand about the site of the works should be
covered over with turf or cinders, to prevent its blowing
about and getting into the buildings. It is also of import-
ance that stand pipes should be placed about the works
with a good pressure of water, the necessary hose being
kept in certain known places where they can be at once
got at in the case of fire, such as the danger area laboratory,
the foreman's office, &c. It is also desirable that the above
precautions against fire should be tested once a week.
With regard to the heating of the various- buildings in the
winter, steam pipes only should be used, and should be
brought from a boiler-house outside the danger area, and
should be covered with kieselguhr or fossil meal and tarred
canvas. These pipes may be supported upon poles. A
stove of some kind should be placed in the corner of each
building, but it must be entirely covered in with woodwork,
and as small a length of steam pipes should be within the
building as possible.
In the case of a factory where nitro-glycerine and
dynamite are manufactured, it is necessary that the work-
people should wear different clothes upon the danger area
than usual, as they are apt to become impregnated with
nitro-glycerine, and thus not very desirable or safe to wear
See also Berthelot, Comptes Rendus, 1900, 131 [12], 519-521.
10
NITRO-EXPLOSIVES.
outside the works. It is also necessary that these clothes
should not contain any pockets, as this lessens the chance
of matches or steel implements being taken upon the
danger area. Changing houses, one for the men, and
another for the girls, should also be provided. The tools
used upon the danger area should, whenever the building
is in use, or contains explosives, be made of phosphor
bronze or brass, and brass nails or wooden pegs should be
used in the construction of all the buildings.
Lightning Conductors. — The Explosive Substances
Act, 38 Viet. ch. 17, clause 10, says, " Every factory magazine
and expense magazine in a factory, and every danger build-
ing in a magazine, shall have
attached thereto a sufficient
lightning conductor, unless by
reason of the construction by
excavation or the position of
such magazine or building, or
otherwise, the Secretary of
State considers a conductor
unnecessary, and every danger
building in a factory shall, if
so required by the Secretary
of State, have attached thereto a sufficient lightning con-
ductor."
The exact form of lightning conductor most suitable
for explosive works and buildings has not yet been defin-
itely settled. Lightning-rod engineers favour what is
known as the Melsens system, due to Professor Melsens,
of Brussels, and Professor Zenger, of Prague, but first
suggested by the late Professor Clerk-Maxwell. In a
paper read before the British Association, Clerk-Maxwell
proposed to protect powder-magazines from the effects of
lightning by completely surrounding or encasing them with
sheet metal, or a cage of metallic conductors. There were,
however, several objections to his system as he left it.
& A 4 ft I
FIG. 2. — MELSENS SYSTEM OF
LIGHTNING CONDUCTORS.
LIGHTNING CONDUCTORS. II
Professor Melsens* has, while using the idea, made
several important alterations. He has multiplied the
terminals, the conductors, and the earth-connections. His
terminals are very numerous, and assume the form of an
aigrette or brush with five or seven points, the central point
being a little higher than the rest, which form with it an
angle of 45°. He employs for the most part galvanised-
iron wire. He places all metallic bodies, if they are of any
considerable size, in communication with the conducting
system in such a manner as to form closed metallic circuits.
His system is illustrated in Fig. 2, taken from Arms and
Explosives.
This system is a near approximation to J. C. Maxwell's
cage. The system was really designed for the protection
of powder-magazines or store buildings placed in very
exposed situations. Zenger's system is identical with that
of Melsens, and has been extensively tried by the Austrian
military authorities, and Colonel Hess has reported upon
the absolute safety of the system.
The French system of protecting powder-magazines is
shown in Fig. 3, where there are no brush terminals or
aigrettes. The French mili-
tary authorities also protect
magazines by erecting two
or more lightning - rods on
poles of sufficient height
placed close to, but not touch- FlG> 3._FRENCH SYSTEM OF
ing, the Walls of the magazine. LIGHTNING CONDUCTORS.
These conductors are joined below the foundations and
earthed as usual.
In the instructions issued by the Government, it is
stated that the lightning-rods placed upon powder-mills
should be of such a height, and so situated, that no danger
is incurred in igniting the powder-dust in the air by the
lightning discharge at the pointed rod. In such a case a
* Belgian Academy of Science.
12
NITRO-EXPLOSIVES.
fork or aigrette of five or more points should invariably be
used in place of a single point.
In Fig. 4 (a and b) is shown the Government method
for protecting buildings in which explosives are made or
FIG. 4«. — GOVERNMENT SYSTEM OF LIGHTNING CONDUCTORS FOR LARGE BUILDINGS.
stored. Multiple points or aigrettes would be better. Lord
Kelvin and Professor Melsens favour points, and it is
generally admitted that lightning does not strike buildings
at a single point, but rather in a sheet ; hence, in such
FIG. \b. — GOVERNMENT SYSTEM OF LIGHTNING CONDUCTORS FOR SMALL BUILDINGS.
cases, or in the event of the globular form being assumed
by the lightning, the aigrette will constitute a much more
effective protection than a single point. As to the spacing
of conductors, they may, even on the most important build-
SYSTEMS OF PROTECTION. 13
ings, be spaced at intervals of 50 feet. There will then be
no point on the building more than 25 feet from the con-
ductor. This " 25-feet rule" can be adhered to with
advantage in all overground buildings for explosives.
Underground magazines should, whenever possible,
also be protected, because, although less exposed than
overground buildings, they frequently contain explosives
packed in metal cases, and hence would present a line of
smaller electrical resistance than the surrounding earth
would offer to the lightning. The conductor should be
arranged on the same system as for overground build-
ings, but be applied to the surface of the ground over
the magazines.
In all situations where several conductors are joined
in one system, the vertical conductors should be con-
nected both at the top and near the ground line. The
angles and the prominent portions of a building being
the most liable to be struck, the conductors should be
carried over and along these projections, and therefore
along the ridges of the roof. The conductors should be
connected to any outside metal on the roofs and walls,
and specially to the foot of rain-water pipes.
All the lightning conductors should be periodically
tested, to see that they are in working condition, at least
every three months, according to Mr Richard Anderson.
The object of the test is to determine the resistance of
the earth-connection, and to localise any defective joints
or parts in the conductors. The best system of testing
the conductors is to balance the resistance of each of the
earths against the remainder of the system, from which
the state of the earths may be inferred with sufficient
accuracy for all practical purposes.
Captain Bucknill, R.E., has designed an instrument
to test resistance which is based on the Post Office
pattern resistance coil, and is capable of testing to
approximate accuracy up to 200 ohms, and to measure
roughly up to 2,000 ohms. Mr R. Anderson's apparatus
14 NITRO-EXPLOSIVES.
is also very handy, consisting of a case containing three
Leclanche cells, and a galvanometer with a " tangent "
scale and certain standard resistances. Some useful
articles on the protection of buildings from lightning
will be found in Arms and Explosives, July, August,
and September 1892, and by Mr Anderson, Brit. Assoc.,
1878-80.
Nitro-Glycerine. — One of the most powerful of modern
explosive agents is nitro-glycerine. It is the explosive
contained in dynamite, and forms the greater part of the
various forms of blasting gelatines, such as gelatine dyna-
mite and gelignite, both of which substances consist of a
mixture of gun-cotton dissolved in nitro-glycerine, with
the addition of varying proportions of wood-pulp and salt-
petre, the latter substances acting as absorbing materials
for the viscid gelatine. Nitro-glycerine is also largely used
in the manufacture of smokeless powders, such as cordite,
ballistite, and several others.
Nitro-glycerol, or glycerol tri-nitrate, was discovered
by Sobrero in the year 1847. In a letter written to
M. Pelouse, he says, u when glycerol is poured into a
mixture of sulphuric acid of a specific gravity of 1.84,
and of nitric acid of a gravity of 1.5, which has been
cooled by a freezing mixture, that an oily liquid is
formed." This liquid is nitro-glycerol, or nitro-glycerine,
which for some years found no important use in the arts,
until the year 1863, when Alfred Nobel first started a
factory in Stockholm for its manufacture upon a large
scale ; but on account of some serious accidents taking
place, its use did not become general.
It was not until Nobel conceived the idea (in 1866)
of absorbing the liquid in some absorbent earth, and
thus forming the material that is now known as dyna-
mite, that the use of nitro-glycerine as an explosive
became general.
Among those who improved the manufacture of
NITROGLYCERINE. 15
nitro-glycerine was Mowbray, who, by using pure gly-
cerine and nitric acid free from nitrous acid, made very
great advances in the manufacture. Mowbray was pro-
bably the first to use compressed air for the purpose of
keeping the liquids well agitated during the process of
nitration, which he conducted in earthenware pots, each
containing a charge of 17 Ibs. of the mixed acids and
2 Ibs. of glycerol.
A few years later (1872), MM. Boutnny and Faucher,
of Vonges,* proposed to prepare nitro-glycerine by mix-
ing the sulphuric acid with the glycerine, thus forming a
sulpho-glyceric acid, which was afterwards mixed with a
mixture of nitric and sulphuric acids. They claimed for
this method of procedure that the final temperature is
much lower. The two mixtures are mixed in the pro-
portions— Glycerine, 100 ; nitric acid, 280 ; and sulphuric
acid, 600. They state that the rise of temperature upon
mixing is limited from 10° to 15° C. ; but this method
requires a period of twenty-four hours to complete the
nitration, which, considering the danger of keeping the
nitro-glycerine in contact with the mixed acids for so
long, probably more than compensates for the somewhat
doubtful advantage of being able to perform the nitra-
tion at such a low temperature. The Boutnny process
was in operation for some time at Pembrey Burrows in
Wales, but after a serious explosion the process was
abandoned.
Nitro-glycerine is now generally made by adding the
glycerine to a mixture of sulphuric and nitric acids. The
sulphuric acid, however, takes no part in the reaction,
but is absolutely necessary to combine with the water that
is formed by the decomposition, and thus to keep up the
strength of the nitric acid, otherwise lower nitrates of
glycerine would be formed that are soluble in water, and
* Comptes Rendus, 75 ; and Desortiaux, "Traite sur la Poudre,'
684-686.
l6 NITRO-EXPLOSIVES.
which would be lost in the subsequent process of washing
to which the nitro-compound is subjected, in order to
remove the excess of acids, the retention of which in the
nitro-glycerol is very dangerous. Nitro-glycerol, which
was formerly considered to be a nitro-substitution com-
pound of glycerol, was thought to be formed thus —
but more recent researches rather point to its being re-
garded as a nitric ether of glycerol, or glycerine, and to
its being formed thus —
92 227
[OH
The formula of glycerine is C3H8O3, or C3H5 J OH
[OH
( PNCX
and that of the mono-nitrate of glycerine, C3H5 | OH
[OH
[ ONO2
and of the tri-nitrate or (nitro-glycerine), C3H5 -J ONO.,
° [ ONO2
that is, the three hydrogens of the semi-molecules of
hydroxyl in the glycerine have been replaced by the
NO2 group.
In the manufacture upon the large scale, a mixture
of three parts by weight of nitric acid and five parts of
sulphuric acid are used. From the above equation it
will be seen that every I Ib. of glycerol should give
(227 -4-1 \
— - - = 2.47 J, but in practice
the yield is only about 2 Ibs. to 2.22, the loss being
accounted for by the unavoidable formation of some of
the lower nitrate, which dissolves in water, and is thus
washed away, and partly perhaps to the presence of a
little water (or other non-nitrable matter) in the glycerine,
but chiefly to the former, which is due to the acids having
become too weak.
\
CHAPTER II.
MANUFACTURE OF NITRO-GLYCERINE.
Properties of Nitro-Glycerine — Manufacture of Nitro-Glycerine — Nitration —
The Nathan Nitrator — Separation — Filtering and Washing — The Waste
Acids — Treatment of the Waste Acid from the Manufacture of Nitro-
Glycerine and Gun-Cotton.
Properties of Nitro - Glycerine. — Nitro-glycerol is a
heavy oily liquid of specific gravity 1.6 at 15° C, and
when quite pure is colourless. The commercial product
is a pale straw yellow, but varies much according to the
purity of the materials used in its manufacture. It is
insoluble in water, crystallises at 10.5° C., but different com-
mercial samples behave very differently in this respect,
and minute impurities prevent or delay crystallisation.
Solid nitro-glycerol* melts at about 12° C., but requires
to be exposed to this temperature for some time before
melting. The specific gravity of the solid form is 1.735
at +10° C. ; it contracts one-twelfth of its volume in
solidifying. Beckerheimf gives the specific heat as
0.4248 between the temperatures of 9.5° and 9,8° C., and
L. de Bruyn gives the boiling point as above 200°.
Nitro-glycerine has a sweet taste, and causes great
depression and vertigo. It is soluble in ether, chloro-
form, benzene, glacial acetic acid, and nitro-ben/ene, in
1.75 part of methylated spirit, very nearly insoluble in
water, and practically insoluble in carbon bisulphide.
Its formula is C3H5(NO3)3, and molecular weight 227.
* Di-nitro-mono chlorhydrin, when added to nitroglycerine up to
20 per cent., is said to prevent its freezing,
t Isb., Chem. Tech., 22, 481-487. 1876.
B
1 8 NITRO-EXPLOSIVES.
When pure, it may be kept any length of time without
decomposition. Berthelot kept a sample for ten years,
and Mr G. M'Roberts, of the Ardeer Factory, for nine
years, without their showing signs of decomposition ; but
if it should contain the smallest trace of free acid, decom-
position is certain to be started before long. This will
generally show itself by the formation of little green spots
in the gelatine compounds, or a green ring upon the sur-
face of liquid nitro-glycerine. Sunlight will often cause
it to explode ; in fact, a bucket containing some water
that had been used to wash nitro-glycerine, and had been
left standing in the sun, has in our experience been known
to explode with considerable force. Nitro-glycerine when
pure is quite stable at ordinary temperatures, and samples
have been kept for years without any trace of decomposition.
It is very susceptible to heat, and even when quite pure
will not stand a temperature of 100° C. for a longer period
than a few hours, without undergoing decomposition. Up
to a temperature of 45° C., however, properly made and
purified nitro-glycerine will remain unchanged almost
indefinitely. The percentage composition of nitro-
glycerine is as follows : —
Found. Theory for C3H5(NO3)3.
Carbon - 15.62 15.86 per cent.
Hydrogen 2.40 2.20 „
Nitrogen 17.90 18.50 „
Oxygen - ... 63.44 „
The above analysis is by Beckerheim. Sauer and Adou
give the nitrogen as 18.35 to 10.54 per cent, by Dumas'
method ; but I have never found any difficulty in obtain-
ing percentages as high as 18.46 by the use of Lunge's
nitrometer. The decomposition products by explosion
are shown by the following equation —
that is, it contains an excess of 3.52 per cent, of oxygen
above that required for complete combustion ; 100 grms.
would be converted into —
PROPERTIES OF NITROGLYCERINE. 19
Carbonic Acid (CO)o 58.15 per cent.
Water - - - 19.83 „
Oxygen - 3. 5 2 per cent.
Nitrogen- 18.50 „
The volume of gases produced at o° and 760 mm.,
calculated from the above, is 714 litres per kilo, the water
being taken as gaseous. Nitre-glycerine is decomposed
differently if it is ignited as dynamite (i.e., kieselguhr
dynamite), and if the gases are allowed to escape freely
under a pressure nearly equal to that of the atmosphere.
Sarrau and Vieille obtained under these conditions, for
100 volumes of gas—
NO - 48.2 per cent.
CO - 35.9 „
C02 - - 12.7 „
H 1.6 per cent.
N 1.3 „
CH4 - -- 0.3 „
These conditions are similar to those under which a mining
charge, simply ignited by the cap, burns away slowly under
a low pressure (i.e., a miss fire). In a recent communica-
tion, P. F. Chalon (Engineering and Mining Journal, 1892)
says, that in practice nitro-glycerine vapour, carbon mon-
oxide, and nitrous oxide, are also produced as the result of
detonation, but he attributes their formation to the use of
a too feeble detonator.
Nitro-glycerine explodes very violently by concussion.
It may be burned in an open vessel, but if heated above
250° C. it explodes. Professor C. E. Munroe gives the
firing point as 2O3°-2O5° C., and L. de Bruyii* states its
boiling point as 185°. He used the apparatus devised by
Horsley. The heat of formation of nitro-glycerine, as
deduced from the heat of combustion by M. Longuinine,
is 432 calories for I grm. ; and the heat of combustion
equals 1,576 cals. for I grm. In the case of nitro-glycerine
the heat of total combustion and the heat of complete
decomposition are interchangeable terms, since it contains
an excess of oxygen. According to Dr W. H. Perkin,
F.R.S.,f the magnetic rotation of nitro-gylcerine is 5,407,
* Jour. Soc. Chem. Ind., June 1896, p. 471.
t Jour. Chem. Soc., W. H. Perkin, 1889, p. 726.
20
NITRO-EXPLOSIVES.
and that of tri-methylene nitrate, 4.769 (cliff. = .638). Dr
Perkin says : " Had nitro-glycerine contained its nitrogen
in any other combination with oxygen than as — O — NO9,
as it might if its constitution had been represented as
C3H2(NO2)3(OH)3, the rotation when compared with propyl
nitrate (4.085) would be abnormal."
The solubility of nitro-glycerine in various solvents has
been investigated by A. H. Elliot ; his results may be
summarised as follows : —
Solvent.
Cold.
Warm.
Water -
Insoluble
Slightly soluble.
Alcohol, absolute
93%-
» 80 %-
» 50%-
Methyl alcohol
Amyl „
Ether, ethylic -
,, acetic -
Chloroform
Acetone -
Sulphuric acid (1.845)
Nitric acid (1.400) -
Hydrochloric acid (1.200)
Acetic acid, glacial -
Carbolic acid -
Astral oil
Olive „
Stearine oil
Mineral jelly -
Glycerine
Benzene -
Nitro-benzene -
Toluene -
Carbon bi-sulphide -
Turpentine
Petroleum naphtha, 71° -
76° B.
Soluble
55
Slowly soluble
Insoluble
Soluble
55
55
55
55
Slowly soluble
Insoluble, decom-
posed
Soluble
>5
Insoluble
Soluble
5)
Insoluble
Soluble • -
Insoluble
Soluble.
Slightly soluble.
Soluble.
Slowly soluble.
Soluble.
55
Insoluble.
Soluble.
55
Insoluble.
55
Soluble.
Slightly affected.
Soluble.
Insoluble.
OF THE
UNIVERSITY
OF
PROPERTIES OF NITRO-GLYCERINE.
21
Solvent.
Caustic soda (i : 10 solu-
tion)
Borax, 5 % solution -
Ammonia (.980)
Ammonium sulph-hydrate
Iron sulphate solution
Iron chloride (1.4 grm. Fe
to 10 c.c. N2O)
Tin chloride -
Cold.
Insoluble
Insoluble, sulphur
separates
Slightly affected -
Slowly affected
Slightly affected -
Warm.
Insoluble.
slightly
affected.
Decomposed.
Affected.
Decomposed.
Affected.
Many attempts have been made to prepare nitro-
glycerine explosives capable of withstanding comparatively
low temperatures without freezing, but no satisfactory solu-
tion of the problem has been found. Among the substances
that have been proposed and used with more or less success,
are nitro-benzene, nitro-toluene, di-nitro-mono-chlorhydrine,
solid nitro derivatives of toluene,* are stated to lower the
freezing point of nitro-glycerine to —20° C. without alter-
ing its sensitiveness and stability. The subject has been
investigated by S. Nauckhoff,f who states that nitro-
glycerine can be cooled to temperatures ( — 40° to —50°
C.) much below its true freezing point, without solidifying,
by the addition of various substances. When cooled by
means of a mixture of solid carbon, dioxide, and ether, it
sets to a glassy mass, without any perceptible crystallisation.
The mass when warmed to o° C. first rapidly liquefies and
then begins to crystallise. The true freezing point of pure
nitro-glycerine was found to be 12.3° C. The technical
product, owing to the presence of di-nitro-glycerine, freezes
at 10.5° C. According to Raoult's law, the lowering of
* Eng. Pat. 25,797, November 1904.
t Z. Angeiv. Chem., 1905, 18, 11-22, 53-60.
22 NITRO-EXPLOSIVES.
the freezing point caused by in grms. of a substance with
the molecular weight M, when dissolved in 100 grms. of
the solvent, is expressed by the formula : A — E vv, where
E is a constant characteristic for the solvent in question.
The value of E for nitro-glycerine was found to be 70.5
when calculated, according to Van 't Hoff's formula, from
the melting point and the latent heat of fusion of the
substance. Determinations of the lowering of the freezing
point of nitro-glycerine by additions of benzene, nitro-
benzene, di-nitro-benzene, tri-nitro-benzene, p.-nitro-toluene,
o.-nitro-toluene,di-nitro-toluene,naphthalene,nitro-naphtha-
lene, di-nitro-naphthalene, ethyl acetate, ethyl nitrate, and
methyl alcohol, gave results agreeing fairly well with Raoult's
formula, except in the case of methyl alcohol, for which the
calculated lowering of the freezing point was greater than
that observed, probably owing to the formation of complex
molecules in the solution. The results show that, in general,
the capacity of a substance to lower the freezing point of
nitro-glycerine depends, not upon its freezing point, or its
chemical composition or constitution, but upon its molecular
weight. Nauckhoff states that a suitable substance for
dissolving in nitro-glycerine, in order to lower the freezing
point of the latter, must have a relatively low molecular
weight, must not appreciably diminish the explosive power
and stability of the explosive, and must not be easily
volatile at relatively high atmospheric temperatures ; it
should, if possible, be a solvent of nitro-cellulose, and in
every case must not have a prejudicial influence on the
gelatinisation of the nitro-cellulose.
Manufacture of Nitro-Glycerine. — Nitro-glycerine is
prepared upon the manufacturing scale by gradually adding
glycerine to a mixture of nitric and sulphuric acids of great
strength. The mixed acids are contained in a lead vessel,
which is kept cool by a stream of water continually passing
through worms in the interior of the nitrating vessel, "and
NITRATION OF GLYCERINE. 23
•
the glycerine is gradually added in the form of a fine stream
from above. The manufacture can be divided into three
distinct operations, viz., nitration, separation, and washing,
and it will be well to describe these operations in the above
order.
Nitration. — The most essential condition of nitrating
is the correct composition and strength of the mixed acids.
The best proportions have been found to be three parts by
weight of nitric acid of a specific gravity 1.525 to 1.530, and
containing as small a portion of the oxides of nitrogen as
possible, to five parts by weight of sulphuric acid of a
specific gravity of 1.840 at 15° C., and about 97 per cent,
of mono-hydrate. It is of the very greatest importance
that the nitric acid should be as strong as possible. Nothing
under a gravity of 1.52 should ever be used even to mix
with stronger acid, and the nitration will be proportional
to the strength of the acid used, provided the sulphuric
acid is also strong enough. It is also of great importance
that the oxides of nitrogen should be low, and that they
should be kept down to as low as I per cent, or even lower.
It is also very desirable that the nitric acid should contain
as little chlorine as possible. The following is the analysis
of a sample of nitric acid, which gave very good results upon
the commercial scale: — Specific gravity, 1.525, N2O4, 1.03
per cent. ; nitric acid (HNO3), 95.58 per cent.
The amount of real nitric acid (mono hydrate) and
the amount of nitric peroxide present in any sample
should always be determined before it is us,ed for nitrating
purposes. The specific gravity is not a sufficient guide to
the strength of the acid, as an acid having a high gravity,
due to some 3 or 4 per cent, of nitric oxides in solution,
will give very poor nitration results. A tenth normal
solution of sodium hydroxide (NaOH), with phenol-
phthalein as indicator, will be found the most convenient
method of determining the total acid present. The follow-
ing method will be found to be very rapid and reliable : —
24 NITRO-EXPLOSIVES.
Weigh a 100 c.c. flask, containing a few cubic centimetres
of distilled water, and then add from a pipette I c.c. of the
nitric acid to be examined, and reweigh (this gives the
weight of acid taken). Now make up to 100 c.c. at 15° C. ;
shake well, and take out 10 c.c. with a pipette ; drain into a
small Erlenmeyer flask, and add a little of the phenol-
phthalein solution, and titrate with the tenth normal soda
solution.
The nitric peroxide can be determined with a solu-
N
tion of potassium permanganate of — strength, thus :
Take a small conical flask, containing about 10 c.c. of water,
and add from a burette 10 to 16 c.c. of the permanganate
solution ; then add 2 c.c. of the acid to be tested, and shake
gently, and continue to add permanganate solution as long
as it is decolourised, and until a faint pink colour is
permanent.
N
Example. permanganate 3.16 grms. per litre, I c.c.
= 0.0046 grm. N2O4, 2 c.c. of sample of acid specific gravity
1.52 = 3.04 grms. taken for analysis. Took 20 c.c. perman-
ganate solution, 0.0046 x 20 = .092 grm. N9O4, and— —
3-°4
= 3.02 per cent. N2O4. The specific gravity should be taken
with an hydrometer that gives the specific gravity directly,
or, if preferred, the 2 c.c. of acid may be weighed.
A very good method of rapidly determining the strength
of the sulphuric acid is as follows : — Weigh out in a small
weighing bottle, as nearly as possible, 2.45 grms. This is
best done by running in 1.33 c.c. of the acid (i-33X 1.84
= 2.447). Wash into a large Erlenmeyer flask, carefully
washing out the bottle, and also the stopper, &c. Add a
drop of phenol-phthalein solution and titrate, with a half
normal solution of sodium hydrate (use a 100 c.c. burette).
Then if 2.45 grms. exactly have been taken, the readings on
the burette will equal percentages of H9SO4 (mono-hydrate)
MIXING ACIDS FOR NITRATION. 25
if not, calculate thus : — 2.444 grins, weighed, required 95.4
c.c. NaOH. Then-
2.444 : 954 : : 2-45 : ^ = 95-^4 per cent. H2SO4.
It has been proposed to free nitric acid from the oxides
of nitrogen by blowing compressed air through it, and thus
driving the gases in solution out. The acid was contained
in a closed lead tank, from which the escaping fumes were
conducted into the chimney shaft, and on the bottom of
which was a lead pipe, bent in the form of a circle, and
pierced with holes, through which the compressed air was
made to pass ; but the process was not found to be of a
very satisfactory nature, and it is certainly better not to
allow the formation of these compounds in the manufacture
of the acid in the first instance. Another plan, however,
is to heat the acid gently, and thus drive out the nitrous
gases. Both processes involve loss of nitric acid.
Having obtained nitric and sulphuric acids as pure as
possible, the next operation is to mix them. This is best
done by weighing the carboys in which the acids are
generally stored before the acids are drawn off into them
from the condensers, and keeping their weights constantly
attached to them by means of a label. It is then a simple
matter to weigh off as many carboys of acid as may be
required for any number of mixings, and subtract the
weights of the carboys. The two acids should, after being
weighed, be poured into a tank and mixed, and subsequently
allowed to flow into an acid egg or montjus, to be after-
wards forced up to the nitrating house in the danger area.
The montjus or acid egg is a strong cast-iron tank, of either
an egg shape, or a cylinder with a round end. If of the
former shape, it would lie on its side, and upon the surface
of the ground, and would have a manhole at one end, upon
which a lid would be strongly bolted down ; but if of the
latter shape, the lid, of course, is upon the top, and the
montjus itself is let into the ground. In either case, the
principle is the same. One pipe, made of stout lead, goes
26 NITRO-EXPLOSIVES.
to the bottom, and another just inside to convey the com-
pressed air, the acids flowing away as the pressure is put on,
just as blowing down one tube of an ordinary wash-bottle
forces the water up the other tube to the jet. The pressure
necessarily will, of course, vary immensely, and will depend
upon the height to which the acid has to be raised and the
distance to be traversed.
The mixed acids having been forced up to the danger
area, and to a level higher than the position of the nitrating
house, should, before being used, be allowed to cool, and
leaden tanks of sufficient capacity to hold at least enough
acid for four or five nitrations should be placed in a wooden
house upon a level at least 6 or 7 feet above the nitrating
house. In this house also should be a smaller lead tank,
holding, when filled to a certain mark, just enough of the
mixed acids for one nitration. The object of this tank is,
that as soon as the man in charge knows that the last
nitration is finished, he refills this smaller tank (which
contains just enough of the mixed acids), and allows its
contents to flow down into the nitrating house and into the
nitrator, ready for the next nitration. The nitration is
usually conducted in a vessel constructed of lead, some 4
feet wide at the bottom, and rather less at the topx and
about 4 feet or so high. The size, of course, depends upon
the volume of the charge it is intended to nitrate at one
operation, but it is always better that the tank should be
only two-thirds full. A good charge is 16 cwt. of the mixed
acids, in the proportion of three to five ; that is, 6 cwt. of
nitric acid, and 10 cwt. of sulphuric acid, and 247 Ibs. of
glycerine.
Upon reference to the equation showing the formation
of nitro-glycerine, it will be seen that for every I Ib. of
glycerine 2.47 Ibs. of nitro-glycerine should be furnished,*
but in practice the yield is only a little over 2 Ibs., the
297 X I
*" Thus if 92 Ibs. glycerine give 227 Ibs. nitro-glycerine, — — —
-2.47 Ibs.
CONSTRUCTION OF NITRATOR. 2/
loss being accounted for by the unavoidable formation of
some of the lower nitrate of glycerine (the mono-nitrate),
which afterward dissolves in the washing waters. The
lead tank (Fig. 5) is generally cased in woodwork, with
a platform in front for the man in charge of the nitrating
to stand upon, and whence to work the various taps. The
top of the tank is closed in with a dome of lead, in which is
a small glass window, through which the progress of the
nitrating operation can be watched. From the top of this
FIG. 5.— TOP OF NITRATOR. A, Fume Pipe ; J3, Water Pipes for Cooling ; C, Acid Mixture
Pipe ; E, Compressed Air ; G, Glycerine Pipe and Funnel ; T, Thermometer ; W ,
Window.
dome is a tube of lead which is carried up through the
roof of the building. It serves as a chimney to carry off
the acid fumes which are given off during the nitration.
The interior of this tank contains at least three concentric
spirals of at least i-inch lead pipe, through which water can
be made to flow during the whole operation of nitrating.
Another lead pipe is carried through the dome of the tank,
as far as the bottom, where it is bent round in the form of
28 NITRO-EXPLOSIVES.
a circle. Through this pipe, which is pierced with small
holes, about I inch apart, compressed air is forced at a
pressure of about 60 Ibs. in order to keep the liquids in a
state of constant agitation during the whole period of
nitration. There must also be a rather wide pipe, of say 2
inches internal diameter, carried through the dome of the
tank, which will- serve to carry the mixed acid to be used
in the operation into the tank. There is still another pipe
to go through the dome, viz., one to carry the glycerine into
the tank. This need not be a large bore pipe, as the
glycerine is generally added to the mixed acids in a thin
stream (an injector is often used).
Before the apparatus is ready for use, it requires to
have two thermometers fixed, one long one to reach to
the bottom of the tank, and one short one just long
enough to dip under the surface of the acids. When the
tank contains its charge, the former gives the tempera-
ture of the bottom, and the latter of the top of the
mixture. The glycerine should be contained in a small
cistern, fixed in some convenient spot upon the wall of
the nitrating house, and should have a pipe let in flush
with the bottom, and going through the dome of the
nitrating apparatus. It must of course be provided with
a tap or stop-cock, which should be placed just above
the point where the pipe goes through the lead dome.
Some method of measuring the quantity of glycerine
used must be adopted. A gauge-tube graduated in
inches is a very good plan, but it is essential that the
graduations should be clearly visible to the operator
upon the platform in front of the apparatus. A large
tap made of earthenware (and covered with lead) is
fixed in the side of the nitrating tank just above the
bottom, to run off the charge after nitration. This should
be so arranged that the charge may be at option run
down the conduit to the next house or discharged into
a drowning tank, which may sometimes be necessary in
cases of decomposition. The drowning tank is generally
POINTS IN NITRATION. 29
some 3 or 4 yards long and several feet deep, lined
with cement, and placed close outside the building.
The apparatus having received a charge of mixed
acids, the water is started running through the pipes
coiled inside the tank, and a slight pressure of com-
pressed air is turned on,* to mix the acids up well before
starting. The nitration should not be commenced until
the two thermometers register a temperature of 18° C.
The glycerine tap is then partially opened, and the
glycerine slowly admitted, and the compressed air turned
on full, until the contents of the apparatus are in a state
of very brisk agitation. A pressure of about 40 Ibs.
is about the minimum (if 247 Ibs. of glycerine and 16
cwt. of acids are in the tank). If the glycerine tube is
fitted with an injector, it may be turned on almost at
once. The nitration will take about thirty minutes to
complete, but the compressed air and water should be
kept on for an additional ten minutes after this, to give
time for all the glycerine to nitrate. The temperature
should be kept as low as possible (not above 18° C.).
The chief points to attend to during the progress of
the nitration are —
1. The temperature registered by the two ther-
mometers.
2. The colour of the nitrous fumes given off (as seen
through the little window in the dome of the apparatus).
3. The pressure of the compressed air as seen from
a gauge fixed upon the air pipe just before it enters the
apparatus.
4. The gauge showing the quantity of glycerine used.
The temperature, as shown by either of the two ther-
mometers, should not be at any time higher than 25° C.
* At the Halton Factory, Germany, cylinders of compressed
carbon dioxide are connected with the air pipes so that in the event of
a failure of the air supply the stirring can be continued with this gas
if necessary.
3O NITRO-EX PLOSIVES.
If it rises much above this point, the glycerine should be
at once shut off, and the pressure of air increased for
some few minutes until the temperature falls, and no
more red fumes are given off.
The nitration being finished, the large earthenware
tap at the bottom of the tank is opened, and the charge
allowed to flow away down the conduit to the next
building, i.e., to the separator.
The nitrating house is best built of wood, and should
have a close-boarded floor, which should be kept scrupu-
lously clean, and free from grit and sand. A wooden
pail and a sponge should be kept in the house in order
that the workman may at once clean up any mess that
may be made, and a small broom should be handy, in
order that any sand, &c., may be at once removed. It
is a good plan for the nitrator to keep a book in which
he records the time of starting each nitration, the
temperature at starting and at the finish, the time
occupied, and the date and number of the charge, as
this enables the foreman of the danger area at any time
to see how many charges have been nitrated, and gives
him other useful information conducive to safe working.
Edward Liebert has devised an improvement in the
treatment of nitro-glycerine. He adds ammonium sul-
phate or ammonium nitrate to the mixed acids during
the operation of nitrating, which he claims destroys the
nitrous acid formed according to the equation—
I am not aware that this modification of the process of
nitration is in use at the present time.
The newly made charge of nitro-glycerine, upon
leaving the nitrating house, flows away down the con-
duit, either made of rubber pipes, or better still, of
woodwork, lined with lead and covered with lids made
of wood (in short lengths), in order that by lifting them
at any point the condition of the conduit can be ex-
POSITION OF THE NITRATOR.
P'
amined, as this is of the greatest importance, and the
conduit requires to be frequently washed out and the
sulphate of lead removed. This sulphate always con-
tains nitro-glycerine, and should therefore be burnt in
some spot far removed from any danger building or
magazine, as it frequently explodes with considerable
violence.
In works where the manufacture of nitro-glycerine is
of secondary importance, and some explosive containing
only perhaps 10 per cent, of nitro-
glycerine is manufactured, and where 50
or 100 Ibs. of glycerine are nitrated at
one time, a very much smaller nitrating
apparatus than the one that has been
already described will be probably all
that is required. In this case the form
of apparatus shown in Fig. 6 will be
found very satisfactory. It should be
made of stout lead (all lead used for
tanks, &c., must be "chemical lead"),
and may be made to hold 50 or 100 Ibs.
as found most convenient. This nitrator
can very well be placed in the same house
as the separator ; in fact, where such a
small quantity of nitro-glycerine is re-
quired, the whole series of operations,
nitrating, separation, and washing, &c.,
may very well be performed in the same **' G1ycerine piPe-
building. It will of course be necessary to place the
nitrator on a higher level than the separator, but this can
easily be done by having platforms of different heights, the
nitration being performed upon the highest. The con-
struction of this nitrator is essentially the same as in the
larger one, the shape only being somewhat different. Two
water coils will probably be enough, and one thermometer.
It will not be necessary to cover this form in with wood-
work.
FIG. 6. — SMALL NITKATOR.
2V, Tap for Discharging ;
Pt Water Pipes; ^'.Ther-
mometer ; W, Windows ;
32 NITRO-EXPLOSIVES.
The Nathan Nitrator.* — This nitrator is the patent of
Lt.-Col. F. L. Nathan and Messrs J. M. Thomson and
W. Rintoul of Waltham Abbey, and will probably before
long entirely supersede all the other forms of nitrator on
account of its efficiency and economy of working. With
this nitrator it is possible to obtain from 2.21 to 2.22 parts
of nitro-glycerine from every I part of glycerine. The
apparatus is so arranged that the nitration of the glycerine,
the separation of nitro-glycerine produced, as well as the
operation of "after-separation," are carried out in one
vessel. The usual nitrating vessel is provided with an
acid inlet pipe at the bottom, and a glass separation
cylinder with a lateral exit or overflow pipe at the top.
This cylinder is covered by a glass hood or bell jar during
nitration to direct the escaping air and fumes into a fume
pipe where the flow of the latter may be assisted by an
air injector. The lateral pipe in the separation cylinder
is in connection with a funnel leading to the prewash
tank. The drawing (Fig. 7) shows a vertical section of
the apparatus ; a is the nitrating vessel of usual construction,
having at the bottom an acid inlet pipe with three branches,
one leading to the de-nitrating plant, c leading to the
drowning tank, and d, which extends upwards and has two
branches, e leading to the nitrating acids tank, and /to the
waste acid tank. On the sloped bottom of the nitrating
vessel a lies a coil g of perforated pipe for blowing air, and
there are in the vessel several coils //, three shown in the
drawing, for circulation of cooling water. At the top of
the vessel there is a glass cylinder it having a lateral outlet
j directed into the funnel mouth of a pipe k leading to the
prewash tank. Over the cylinder i is a glass globe /, into
which opens a pipe m for leading off fumes which may
be promoted by a compressed air jet from a pipe r oper-
ating as an injector. Into an opening of the glass dome
/ is inserted a vessel «, which is connected by a flexible
* Eng. Pat. 15,983, August 1901.
THE NATHAN NITRATOR.
33
pipe p to the glycerine tank, and from the bottom of
72, which is perforated and covered with a disc perforated
with holes registering with those through the bottom, this
FIG. 7. — NATHAN'S NITRATOR FOR NITRO-GLYCERINE. (a) Nitrating Vessel ; (ti) to
Separating Vessel ; (c) to Drowning Tank ; (e) Nitrating Acids enter (/) to the
Waste Acids ; (g) Coils for Compressed Air ; (h) Pipes for Cooling Water ; (z) Glass
Cylinder ; (j) Outlet to k \ (K) leading to Prewash Tank ; (/) Glass Dome ; (m) Pipe
to lead off for Escape of Fumes ; («) Vessel ; (/) Pipe conveying Glycerine ; (<?) Knob
to turn off Glycerine ; (r) Compressed Air Jet ; (s) Thermometer.
disc being connected by a stem with a knob q by which
it can be turned so as to throttle or cut off passage of
glycerine through the bottom. s is a thermometer for
indicating the temperature of the contents of the vessel.
In operating with this apparatus the nitrating acid is
C
34 NITRO-EXPLOSIVES.
introduced into the nitrating vessel by opening the cock
of the pipe e. The glycerine is then run in by introducing
n and opening the valve at its bottom, the contents of the
vessel being agitated by air blown through the perforations
of the pipe g. When the glycerine is all nitrated and the
temperature has slightly fallen, the circulation of the water
through the coils h and the air-stirring are stopped, and
the glycerine supply vessel ;/ is removed. The nitro-
glycerine as it separates from the acids is raised by intro-
ducing by the pipe / waste acid from a previous charge,
this displacing the nitro-glycerine upwards and causing
it to flow by the outlet/ and pipe k to the prewash tank.
When nearly all the nitro-glycerine has been separated in
this manner the acids in the apparatus may be run off
by the pipe b to an after separating vessel for further
settling, thus leaving the apparatus free for another nitra-
tion, or the nitrating vessel itself may be used as an after
separating bottle displacing the nitro-glycerine with waste
acid as it rises to the top, or skimming off in the usual
manner. When the separation of the nitro-glycerine is
complete the waste acid is run off and denitrated as usual,
a portion of it being reserved for the displacement of the
nitro-glycerine in a subsequent operation.
In a further patent (Eng. Pat. 3,020, 1903) the authors
propose with the object of preventing the formation and
separation of nitro-glycerine in the waste acids, after the
nitro-glycerine initially formed in the nitrating vessel has
been separated and removed, to add a small quantity of water
to the waste acids ; this is carried out as follows. A relatively
small quantity of water is added, and this prevents all further
separation of nitro-glycerine, and at the same time the
strength of the waste acids is so slightly reduced that their
separation and re-concentration are not affected. " After-
separation " is thus done away with, and the nitro-glycerine
plant simplified and its output increased. After nitration
separation is commenced at a temperature such that when
all the displacing acid has been added, and the separation
SEPARATION OF NITRO-GLYCERINE. 35
of the nitroglycerine is complete, the temperature of the
contents of the nitrating vessel shall not be lower than 15° C.
A sufficient quantity of the displacing acid is then run
off through the waste-acid cock to allow of the remaining
acids being air-stirred without splashing over the top. A
small quantity of water, from 2 to 3 per cent, according to
strength of acid ; if waste consists of sulphuric acid (mono-
hydrate), 62 per cent. ; nitric acid (anhydrous), 33 per cent,
and water 5 per cent. ; temperature 15° C., then 2 per cent,
of water is added ; if waste acids contain less than 4 per
cent, of water of temperature lower than 15° C., from 3 to 5
per cent, of water may have to be added. The water is
added slowly through the separator cylinder, and the con-
tents of the nitrator air-stirred, but not cooled, the tempera-
ture being allowed to rise slowly and regularly as the water
is added — usually about 3° C. for each per cent, of water
added. When air-agitation has been stopped, the acids
are kept at rest for a short time, in order to allow of any
small quantity of initially formed nitro-glycerine adhering
to the coils and sides of the vessel rising to the top. When
this has been separated by displacement, the acids are
ready for denitration, or can be safely stored without further
precaution.
Separation. — The nitro-glycerine, together with the
mixed acids, flows from the nitrating house to the separat-
ing house, which must be on a lower level than the former.
The separating house contains a large lead-lined tank,
closed in at the top with a wooden lid, into which a lead
pipe of large bore is fixed, and which is carried up through
the roof of the building, and acts as a chimney to carry off
any fumes. A little glass window should be fixed in this
pipe in order that the colour of the escaping fumes may
be seen. The conduit conveying the nitro-glycerine enters
the building close under the roof, and discharges its con-
tents into the tank through the pipe G (Fig. 8). The tank
is only about two-thirds filled by the charge. There is in
30 NITRO-EXPLOSIVES.
the side of the tank a small window of thick plate glass,
which enables the workman to see the level of the charge,
and also to observe the progress of the separation, which
will take from thirty minutes to one hour.
The tank should be in connection with a drowning
o
tank, as the charge sometimes gets very dangerous in this
building. It must also be connected by a conduit with the
filter house, and also to the secondary separator by another
conduit. The tank should also be fitted with a compressed
air pipe, bent in the form of a loop. It should lie upon the
*~
FIG. 8. — SEPARATOR. A, Compressed Air Pipes; G, Nitro-glycerine enters from
Nitrator ; N, Nitro-glycerine to P ; Lt Lantern Window ; IV, Window in Side ; S,
Waste Acids to Secondary Separator ; T", Tap to remove last traces of Nitro-glycerine ;
P, Lead Washing Tank ; A, Compressed Air; Wt Water Pipe ; N, Nitro-glycerine
from Separator. _,-
bottom of the vat. The object of this is to mix up the
charge in case it should get too hot through decomposition.
A thermometer should of course be fixed in the lid of the
tank, and its bulb should reach down to the middle of the
nitro-glycerine (which rests upon the surface of the mixed
acids, the specific gravity of the nitro-glycerine being 1.6,
and that of the waste acids 1.7 ; the composition of the
acids is now n per cent. HNO.}, 67 per cent. H2SO4, and
22 per cent, water), and the temperature carefully watched.
If nothing unusual occurs, and it has not been necessary
FILTERING AND WASHING NITROGLYCERINE. 37
W
to bring the compressed air into use, and so disturb the
process of separation, the waste acids may be run away
from beneath the nitro-glycerine, and allowed to flow away
to the secondary separator, where any further quantity of
nitro-glycerine that they contain separates out after rest-
ing for some days. The nitro-
glycerine itself is run into a
smaller tank in the same house,
where it is washed three or
four times with its own bulk of
water, containing about 3 Ibs.
of carbonate of soda to neutral-
ise the remaining acid. This
smaller tank should contain a
lead pipe, pierced and coiled
upon the bottom, through which
compressed air may be passed,
in order to stir up the charge
with the water and soda. A fter
this preliminary washing, the
nitro-glycerine is drawn off into
indiarubber buckets, and poured
down the conduit to the filter
house. The wash waters may
be sent clown a conduit to
another building, in order to
allow the small quantity of
nitro-glycerine that has been Fir
retained in the water as minute
globules to settle, if thought
worth the trouble of saving.
This, of course, will depend upon the usual out-turn of
nitro-glycerine in a day, and the general scale of opera-
tions.
FILTERING AND WASHING
PLANT. IV, Lead Washing Tank ;
WP, Water Pipe ; L, Lid ; S, Nitro-
glycerine from Separator ; A , B, C,
Filtering Tanks; B2, Indiarubber
Bucket.
Filtering- and Washing. — The filter house (Fig. 9),
which must of course be again on a somewhat lower level
38 NITRO-EXPLOSIVES.
than the separating house, must be a considerably larger
building than either the nitrating or separating houses, as
it is always necessary to be washing some five or six
charges at the same time. Upon the arrival of the nitro-
glycerine at this house, it first flows into a lead-lined
wooden tank (w), containing a compressed air pipe, just
like the one in the small tank in the separating house.
This tank is half filled with water, and the compressed air
is turned on from half to a quarter of an hour after the
introduction of the charge. The water is then drawn off,
and fresh water added. Four or five washings are gener-
ally necessary. The nitro-glycerine is then run into the
next tank (A), the top of which is on a level with the
bottom of the first one. Across the top of this tank is
stretched a frame of flannel, through which the nitro-
glycerine has to filter. This removes any solid matters,
such as dirt or scum. Upon leaving this tank, it passes
through a similar flannel frame across another tank (B),
and is finally drawn off by a tap in the bottom of the
tank into rubber buckets. The taps in these tanks are
best made of vulcanite.
At this stage, a sample should be taken to the labora-
tory and tested. If the sample will not pass the tests,
which is often the case, the charge must be rewashed for
one hour, or some other time, according to the judgment of
the chemist in charge. In the case of an obstinate charge,
it is of much more avail to wash a large number of times
with small quantities of water, and for a short time, than to
use a lot of water and wash for half an hour. Plenty of
compressed air should be used, as the compound nitric
ethers which are formed are thus got rid of. As five or six
charges are often in this house at one time, it is necessary
to have as many tanks arranged in tiers, otherwise one or
two refractory charges would stop the nitrating house and
the rest of the nitro-glycerine plant. The chief causes of
the washed material not passing the heat test are, either
that the acids were not clean, or they contained objection-
TESTING NITROGLYCERINE. 39
able impurities, or more frequently, the quality of the
glycerine used. The glycerine used for making nitro-
glycerine should conform to the following tests, some of
which, however, are of greater importance than others. The
glycerine should—
1. Have minimum specific gravity at 15° C. of
1.261.
2. Should nitrify well.
3. Separation should be sharp within half an hour,
without the separation of flocculent matter, nor should any
white flocculent matter (due to fatty acids) be formed when
the nitrated glycerine is thrown into water and neutralised
with carbonate of soda.
4. Should be free from lime and chlorine, and contain
only traces of arsenic, sulphuric acid, &c.
5. Should not leave more than 0.25 per cent, of in-
organic and organic residue together when evaporated in a
platinum dish without ebullition (about 160° C.) or partial
decomposition.
6. Silver test fair.
7. The glycerine, when diluted one-half, should give no
deposit or separation of fatty acids when nitric peroxide
gas is passed through it. (Nos. I, 2, 3, and 5 are the most
essential.)
The white flocculent matter sometimes formed is a very
great nuisance, and any sample of glycerol which gives
such a precipitate when tried in the laboratory should at
once be rejected, as it will give no end of trouble in the
separating house, and also in the filter house, and it will be
very difficult indeed to make the nitro-glycerine pass the
heat test. The out-turn of nitro-glycerine also will be very
low. The trouble will show itself chiefly in the separating
operation. Very often 2 or 3 inches will rise to the surface
or hang about in the nitro-glycerine, and at the point of
contact between it and the mixed acids, and will afterwards
be very difficult to get ricl of by filtration. The material
appears to be partly an emulsion of the glycerine, and
40 NITRO-EXPLOSIVES.
partly due to fatty acids, and as there appears to be no
really satisfactory method of preventing its formation, or
of getting rid of it, the better plan is not to use any
glycerine for nitrating that has been found by experiment
upon the laboratory scale to give this objectionable matter.
One of the most useful methods of testing the glycerine,
other than nitrating, is to dilute the sample one-half with
water, and then to pass a current of nitric peroxide gas
through it, when a flocculent precipitate of elai'dic acid
(less soluble in glycerine than the original oleic acid) will
be formed. Nitrogen peroxide, N9O4, is best obtained by
heating dry lead nitrate (see Allen, " Commercial Organic
Analysis," vol. ii., 301).
When a sample of nitro-glycerine is brought to the
laboratory from the filter house, it should first be examined
to see that it is not acid.* A weak solution of Congo red
or methyl orange may be used. If it appears to be decidedly
alkaline, it should be poured into a separating funnel, and
shaken with a little distilled water. This should be repeated,
and the washings (about 400 c.c.) run into a beaker, a drop
of Congo red or methyl orange added, and a drop or so
N
of : - hydrochloric acid added, when it should give, with
two or three drops at most, a blue colour with the Congo
red, or pink with the methyl orange, &c. The object of
this test is to show that the nitro-glycerine is free from
any excess of soda, i.e., that the soda has been properly
washed out, otherwise the heat test will show the sample
to be better than it is. The heat test must also be
applied.
Upon leaving the filter house, where it has been washed
and filtered, and has satisfactorily passed the heat test, it
* A. Leroux, Bui. Soc. Chim. de /te/.,.xix., August 1905, contends
that experience does not warrant the assumption that free acid is a
source of danger in nitro-glycerine or nitro-cellulose ; free alkali, he
states, promotes their decomposition.
WASTE ACIDS. 41
is drawn off from the lowest tank in indiarubber buckets,
and poured down the conduit leading to the precipitating
house, where it is allowed to stand for a day, or sometimes
longer, in order to allow the little water it still contains to
rise to the surface. In order to accomplish this, it is
sufficient to allow it to stand in covered-in tanks of a
conical form, and about 3 or 4 feet high. In many works
it is previously filtered through common salt, which of
course absorbs the last traces of water. It is then of a
pale yellow colour, and should be quite clear, and can be
drawn off by means of a tap (of vulcanite), fixed at the
bottom of the tanks, into rubber buckets, and is ready for
use in the preparation of dynamite, or any of the various
forms of gelatine compounds, smokeless powders, &c., such
as cordite, ballistite, and many others.
Mikolajezak (Chem. Zeit., 1904, Rep. 174) states that
he has prepared mono- and di-nitro-glycerine, and believes
that the latter compound will form a valuable basis for ex-
plosives, as it is unfreezable. It is stated to be an odourless,
Linfreezable oil, less sensitive to percussion, friction, and
increase of temperature, and to possess a greater solvent
power for collodion-cotton than ordinary nitre-glycerine.
It can thus be used for the preparation of explosives of
high stability, which will maintain their plastic nature even
in winter. The di-nitro-glycerine is a solvent for tri-nitro-
glycerine, it can therefore be mixed with this substance, in
the various gelatine explosives in order to lower the freezing
point.
•
The Waste Acids. — The waste acids from the sepa-
rating house, from which the nitro-glycerine has been as
completely separated as possible, are run down the conduit
to the secondary separator, in order to recover the last
traces of nitro-glycerine that they contain. The composition
of the waste acids is generally somewhat as follows :—
Specific gravity, 1.7075 at 15° C. ; sulphuric acid, 67.2 per
cent. ; nitric acid, 1 1.05 per cent. ; and water, 21.7 per cent.,
42 NITRO-EXPLOSIVES.
with perhaps as much as 2 per cent, of nitric oxide, and of
course varying quantities of nitro-glycerine, which must be
separated, as it is impossible to run this liquid away (unless
it can be run into the sea) or to recover the acids by
distillation as long as it contains this substance. The
mixture, therefore, is generally run into large circular lead-
lined tanks, covered in, and very much like the nitrating
apparatus in construction, that is, they contain worms coiled
round inside, to allow of water being run through to keep
the mixture cool, and a compressed air pipe, in order to
agitate the mixture if necessary. The top also should
contain a window, in order to allow of the interior being
seen, and should have a leaden chimney to carry off the
fumes which may arise from decomposition. It is also
useful to have a glass tube of 3 or 4 inches in diameter sub-
stituted for about a foot of the lead chimney, in order that
the man on duty can at any time see the colour of the fumes
arising from the liquid. There should also be two thermo-
meters, one long one reaching to the bottom of the tank,
and one to just a few inches below the surface of the
liquid.
The nitro-glycerine, of course, collects upon the surface,
and can be drawn off by a tap placed at a convenient height
for the purpose. The cover of the tank is generally conical,
and is joined to a glass cylinder, which is cemented to the
top of this lead cover, and also to the lead chimney. In
this glass cylinder is a hole into which fits a ground glass
stopper, through which the nitro-glycerine can be drawn
off. There will probably never be more than an inch of
nitro-glycerine at the most, and seldom that. It should be
taken to the filter house and treated along with another
charge. The acids themselves may either be run to waste,
or better treated by some denitration plant. This house
probably requires more attention than any other in the
danger area, on account of the danger of the decomposition
of the small quantities of nitro-glycerine, which, as it is
mixed with such a large quantity of acids and water, is very
TREATMENT OF WASTE ACIDS. 43
apt to become hot, and decomposition, which sets up in
spots where a little globule of nitro-glycerine is floating,
surrounded by acids that gradually get hot, gives off
nitrous fumes, and perhaps explodes, and thus causes the
sudden explosion of the whole. The only way to prevent
this is for the workman in charge to look at the thermometers
frequently, and at the colour of the escaping fumes, and if
he should notice a rise of temperature or any appearance
of red fumes, to turn on the water and air, and stir up the
mixture, when probably the temperature will suddenly fall,
and the fumes cease to come off.
The cause of explosions in this building is either the
non-attention of the workmen in charge, or the bursting
of one of the water pipes, by which means, of course, the
water, finding its way into the acids, causes a sudden rise
of temperature. If the latter of these two causes should
occur, the water should at once be shut off and the air
turned on full, but if it is seen that an explosion is likely
to occur, the tank should at once be emptied by allowing
its contents to run away into a drowning tank placed close
outside the house, which should be about 4 feet deep, and
some 1 6 feet long by 6 feet wide ; in fact, large enough to
hold a considerable quantity of water. But this last course
should only be resorted to as a last extremity, as it is
extremely troublesome to recover the small quantity of
nitro-glycerine from the bottom of this tank, which is
generally a bricked and cemented excavation some few
yards from the house.
It has been proposed to treat these waste acids, con-
taining nitro-glycerine, in Mr M. Prentice's nitric acid
retort. In this case they would be run into the retort,
together with nitrate of soda, in a fine stream, and the
small quantity of nitro-glycerine, coming into contact with
the hot mixture already in the retort, would probably be
at once decomposed. This process, although not yet tried,
promises to be a success. Several processes have been
used for the denitration of these acids.
44 NITRO-EXPLOSIVES.
Treatment of the Waste Acid from the Manufacture
of Nitro-Glycerine and Gun-Cotton. — The composition of
these acids is as follows : —
Nitroglycerine and Gun-cotton
Waste Acid.
Sulphuric acid 70 per cent. 78 per cent.
Nitric acid - 10 „ 12 „
Water - 20 „ 10
The waste acid from the manufacture of gun-cotton is
generally used direct for the manufacture of nitric acid, as
it contains a fairly large amount of sulphuric acid, and the
small amount of nitro-cellulose which it also generally con-
tains decomposes gradually and without explosion in the
retort. Nitric acid may be first distilled off, the resulting
sulphuric acid being then added to the equivalent amount
of nitrate of soda. Nitric acid is then distilled over and
condensed in the usual way. Very often, however, the
waste acid is added direct to the charge of nitrate without
previously eliminating the nitric acid. The treatment of
the waste acid from the manufacture of nitro-glycerine is
somewhat different. The small amount of nitro-glycerine
in this acid must always be eliminated. This is effected
either by allowing the waste acid to stand for at least
twenty-four hours in a -big vessel with a conical top, where
all the nitro-glycerine which will have separated to the
surface is removed by skimming ; or, better still, the "water-
ing down process " of Col. Nathan may be employed.
In Nathan's nitrator every existing trace of nitro-glycerine
is separated from the acids in a few hours after the nitra-
tion, and any further formation of nitro-glycerine is
prevented by adding about 2 per cent, of water to the
waste acids, which are kept agitated during the addition.
The waste acid, now free from nitro-glycerine, but which
may still contain organic matter, is denitrated by bringing
it into contact with a jet of steam. The waste acid is
passed in a small stream down through a tower of acid-
resisting stoneware (volvic stone), which is closely packed
NITRIC ACID PLANT. 45
with earthenware, and at the bottom of which is the steam
jet. Decomposition proceeds as the acid meets the steam,
nitric and nitrous acids are disengaged and are passed out
at the top of the tower through a pipe to a series of con-
densers and towers, where the nitric acid is collected. The
nitrous acid may be converted into nitric acid by introduc-
ing a hot compressed air jet into the gases before they pass
into the condensers. Weak sulphuric acid of sp. gr. 1.6
collects in a saucer in which the tower stands, and is then
passed through a cooling worm. The weak sulphuric acid,
now entirely free from nitric and nitrous acids, may be
concentrated to sp. gr. 1.842 and 96 per cent. H2SO4
by any of the well-known processes, e.g., Kessler, Webb,
Benker, Delplace, &c., and it may be used again in the
manufacture of nitro-glycerine or gun-cotton.
Two points in the manufacture of nitro-glycerine are
of the greatest importance, viz., the purity of the glycerine
used, and the strength and purity of the acids used in
the nitration. With regard to the first of these, great care
should be taken, and a complete analysis and thorough
examination, including a preliminary experimental nitra-
tion, should always be instituted. As regards the second,
the sulphuric acid should not only be strong (96 per cent.),
but as free from impurities as possible. With the nitric
acid, which is generally made at the explosive works where
it is used, care must be taken that it is as strong as possible
(97 per cent, and upwards). This can easily be obtained
if the plant designed by Mr Oscar Guttmann * is used.
Having worked Mr Guttmann's plant for some time, I can
testify as to its value and efficiency.
Another form of nitric acid plant, which promises to be
of considerable service to the manufacturer of nitric acid
for the purpose of nitrating, is the invention of the late Mr
Manning Prentice, of Stowmarket. Through the kindness
* "The Manufacture of Nitric Acid," Jour. Soc. Chem. Ind.,
March 1893.
46 NITRO-EXPLOSIVES.
of Mr Prentice, I visited his works to see the plant in
operation. It consists of a still, divided into compartments
or chambers in such a manner that the fluid may pass
continuously from one to the other. The nitric acid being
continuously separated by distillation, the contents of each
division vary — the first containing the full proportion of
nitric acid, and each succeeding one less of the nitric acid,
until from the overflow of the last one the bisulphate of
soda flows away without any nitric acid. The nitrate of
soda is placed in weighed quantities in the hopper, whence
it passes to the feeder. The feeder is a miniature horizontal
pug-mill, which receives the streams of sulphuric acid and
of nitrate, and after thoroughly mixing them, delivers them
into the still, where, under the influence of heat, they rapidly
become a homogeneous liquid, from which nitric acid con-
tinuously distils.
Mr Prentice says : " I may point out that while the
ordinary process of making nitric acid is one of fractional
distillation by time, mine is fractional distillation by space."
" Instead of the operation being always at the same point
of space, but differing by the successive points of time, I
arrange for the differences to take place at different points
of space, and these differences exist at one and the same
points of time." It is possible with this plant to produce
the full product of nitric acid of a gravity of 1.500, or to
obtain the acid of varying strengths from the different still-
heads. One of these stills, capable of producing about
4 tons of nitric acid per week, weighs less than 2 tons. It
is claimed that there is by their use a saving of more than
two-thirds in fuel, and four-fifths in condensing plant.
Further particulars and illustrations will be found in Mr
Prentice's paper {Journal of the Society of CJieinical Industry,
1894, p. 323).
CHAPTER III.
NITRO-CELLULOSE, &c.
Cellulose Properties — Discovery of Gun-Cotton — Properties of Gun-Cotton —
Varieties of Soluble and Insoluble Gun-Cottons — Manufacture of Gun-
Cotton—Dipping and Steeping —Whirling out the Acid — Washing —
Boiling — Pulping — Compressing — The Waltham Abbey Process — Le
Bouchet Process — Granulation of Gun-Cotton — Collodion-Cotton — Manu-
facture— Acid Mixture used — Cotton used, &c. — Nitrated Gun-Cotton —
Tonite — Dangers in Manufacture of Gun-Cotton — Trench's Fire-Ex-
tinguishing Compound — Uses of Collodion-Cotton — Celluloid — Manu-
facture, &c. — Nitro-Starch, Nitro-Jute, and Nitro-Mannite.
The Nitro-Celluloses. — The substance known as cellu-
lose forms the groundwork of vegetable tissues. The
cellulose of the woody parts of plants was at one time
supposed to be a distinct body, and was called lignine, but
they are now regarded as identical. The formula of cellu-
lose is (C6H10O5)X, and it is generally assumed that the
molecular formula must be represented by a multiple of the
empirical formula, C12H20O10 being often regarded as the
minimum. The assumption is based on the existence of
a penta-nitrate and the insoluble and colloidal nature of
cellulose. Green (Zeit. Farb. Text. Ind., 1904, 3, 97) con-
siders these reasons insufficient, and prefers to employ the
single formula C6H10O5. Cellulose can be extracted in
the pure state, from young and tender portions of plants
by first crushing them, to rupture the cells, and then
extracting with dilute hydrochloric acid, water, alcohol,
and ether in succession, until none of these solvents remove
anything more. Fine paper or cotton wool yield very
nearly pure cellulose by similar treatment.
48 NITRO-EXPLOSIVES.
Cellulose is a colourless, transparent mass, absolutely
insoluble in water, alcohol, or ether. It is, however, soluble
in a solution of cuprammoniac solution, prepared from basic
carbonate or hydrate of copper and aqueous ammonia.
The specific gravity of cellulose is 1.25 to 1.45. According
to Schulze, its elementary composition is expressed by the
percentage numbers :—
Carbon - - 44.0 per cent. 44.2 per cent.
Hydrogen 6.3 „ 6.4 „
Oxygen 49.7 „ 49.4 „
These numbers represent the composition of the ash
free cellulose. Nearly all forms of cellulose, however, con-
tain a small proportion of mineral matters, and the union
of these with the organic portion of the fibre or tissue is of
such a nature that the ash left on ignition preserves the
form of the original. " It is only in the growing point of
certain young shoots that the cellulose tissue is free from
mineral constituents" (Hofmeister).
Cellulose is a very inert body. Cold concentrated
sulphuric acid causes it to swell up, and finally dissolves
it, forming a viscous solution. Hydrochloric acid has little
or no action, but nitric acid has, and forms a series of
bodies known as nitrates or nitro-celluloses. Cellulose has
some of the properties of alcohols, among them the power
of forming ethereal salts with acids. When cellulose in any
form, such as cotton, is brought into contact with strong
nitric acid at a low temperature, a nitrate or nitro product,
containing nitryl, or the NO2 group, is produced. The
more or less complete replacement of the hydroxylic
hydrogen by NO2 groups depends partly on the concentra-
tion of the nitric acid used, partly on the duration of the
action. If the most concentrated nitric and sulphuric
acids are employed, and the action allowed to proceed for
some considerable time, the highest nitrate, known as hexa-
nitro-cellulose or gun-cotton, C12H14O4(O.NO.2)6, will be
formed ; but with weaker acids, and a shorter exposure to
GUN-COTTON. 49
their action, the tetra and penta and lower nitrates will be
formed.*
Besides the nitrate, A. Luck f has proposed to use other
esters of cellulose, such as the acetate, benzoate, or butyrate.
It is found that cellulose acetate forms with nitro-glycerine a
gelatinous body without requiring the addition of a solvent.
A sporting powder is proposed composed of 75 parts of
cellulose nitrate (13 per cent. N.) mixed with 13 parts of
cellulose acetate.
The discovery of gun-cotton is generally attributed to
Schonbein (1846), but Braconnot (in 1832) had previously
nitrated starch, and six years later Pelouse prepared nitro-
cotton and various other nitro bodies, and Dumas nitrated
paper, but Schonbein was apparently the first chemist to
use a mixture of strong nitric and sulphuric acids. Many
chemists, such as Piobert in France, Morin in Russia, and
Abel in England, studied the subject ; but it was in
Austria, under the auspices of Baron Von Lenk, that the
greatest progress was made. Lenk used cotton in the form
of yarn, made up into hanks, which he first washed in a
solution of potash, and then with water, and after drying
dipped them in the acids. The acid mixture used consisted
of 3 parts by weight of sulphuric to I part of nitric acid,
and were prepared some time before use. The cotton was
dipped one skein at a time, stirred for a few minutes,
pressed out, steeped, and excess of acid removed by wash-
ing with water, then with dilute potash, and finally with
water. Von Lenk's process was used in England at
Faversham (Messrs Hall's Works), but was given up on
account of an explosion (1847).
Sir Frederick Abel, working at Stowmarket and Waltham
Abbey, introduced several very important improvements
into the process, the chief among these being pulping.
Having traced the cause of its instability to the presence
* The paper by Prof. Lunge, Jour. Amer. Chem. Soc., 1901, 23 [8],
527-579, contains valuable information on this subject,
t Eng. Pat. 24,662, 22nd November 1898.
D
50 NITRO-EXPLOSIVES.
of substances caused by the action of the nitric acid on the
resinous or fatty substances contained in the cotton fibre,
he succeeded in eliminating them, by boiling the nitro-
cotton in water, and by a thorough washing, after pulping
the cotton in poachers.
Although gun-cottons are generally spoken of as nitro-
celluloses, they are more correctly described as cellulose
nitrates, for unlike nitro bodies of other series, they do not
yield, or have not yet done so, amido bodies, on reduction
with nascent hydrogen.* The equation of the formation
of gun-cotton is as follows : —
Cellulose. Nitric Acid. Gun-Cotton. Water.
The sulphuric acid used does not take part in the reaction,
but its presence is absolutely essential to combine with the
water set free, and thus to prevent the weakening of the
nitric acid. The acid mixture used at Waltham Abbey
consists of 3 parts by weight of sulphuric acid of 1.84
specific gravity, and I part of nitric acid of 1.52 specific
gravity. The same mixture is also used at Stowmarket
(the New Explosive Company's Works). The use of
weaker acids results in the formation of collodion-cotton
and the lower nitrates generally.
The nitrate which goes under the name of gun-cotton
is generally supposed to be the hexa-nitrate, and to contain
14.14 per cent, of nitrogen ; but a higher percentage than
13.7 has not been obtained from any sample. It is almost
impossible (at any rate upon the manufacturing scale) to
make pure hexa-nitro-cellulose or gun-cotton ; it is certain
to contain several per cents, of the soluble forms, i.e., lower
nitrates. It often contains as much as 15 or 1 6 per cent.,
and only from i3.O7t to 13.6 per cent, of nitrogen.
* " Cellulose," by Cross and Bevan, ed. by W. R. Hodgkinson, p. 9.
t Mr J. J. Sayers, in evidence before the court in the " Cordite
Case," says he found 15.2 and 16. i per cent, soluble cotton, and
13.07 and 13.08 per cent, nitrogen in two samples of Waltham Abbey
gun-cotton.
NITRO-CELLULOSES. 5 1
A whole series of nitrates of cellulose are supposed
to exist, the highest member being the hexa-nitrate, and
the lowest the mono-nitrate. Gun-cotton was at one time
regarded as the tri-nitrate, and collodion-cotton as the
di-nitrate and mono-nitrate, their respective formula being
given as follows : —
Mono-nitro cellulose C6H9(NO2)O5 = 6.763 per cent, nitrogen.
Di-nitro-cellulose - C6H8(NO2)26g = 11. 11 ,, ,,
Tri-nitro-cellulose - C8H7(NO2)3O5 = 14.14 ,, ,,
But gun-cotton is now regarded as the hexa-nitrate, and
collodion-cotton as a mixture of all the other nitrates.
In fact, chemists are now more inclined to divide nitro-
cellulose into the soluble and insoluble forms, the reason
being that it is quite easy to make a nitro-cellulose entirely
soluble in a mixture of ether-alcohol, and yet containing
as high a percentage of nitrogen as 12.6 ; whereas the di-
nitrate* should theoretically only contain ii.n per cent.
On the other hand, it is not possible to make gun-cotton
with a higher percentage of nitrogen than about 13.7, even
when it does not contain any nitro-cotton that is soluble
in ether-alcohol.f The fact is that it is not at present
possible to make a nitro-cellulose which shall be either
entirely soluble or entirely insoluble, or which will contain
the theoretical content of nitrogen to suit any of the above
formulae for the cellulose nitrates. Prof. G. Lunge gives
the following list of nitration products of cellulose : —
* The penta-nitrate Ci2H1BO6(NO3)g= 12.75 Per cent- nitrogen.
t In the Cordite Trial (1894) Sir ' F. A.Abel said, " Before 1888
there was a broad distinction between soluble and insoluble nitro-
cellulose, collodion-cotton being soluble (in ether-alcohol) and gun-
cotton insoluble." Sir H. E. Roscoe, " That he had been unable to
make a nitro-cotton with a higher nitrogen content than 13.7." And
Professor G. Lunge said, " Gun-cotton always contained soluble
cotton, and "vice versa" These opinions were also generally con-
firmed by Sir E. Frankland, Sir W. Crookes, Dr Armstrong, and
others.
52 NITRO-EXPLOSIVES.
Dodeca-nitro-cellulose - - C24H28Oo0(NO2)12 = 14.16 per cent, nitrogen.
( = old tri-nitro-cellulose)
Endeca-nitro-cellulose - - . Co4H29Oo0(NO2)n =13.50 ,, ,,
Deca-nitro-cellulose - C24H30O20(NO.2)10 =12.78 ,, ,,
Ennea-nitro-cellulose - - Co4H31(X0(NO.>)9 = 11.98 ,, ,,
Octo-nitro-cellulose - C24H32Oo0(NO.2)8 =11.13
( = old di-nitro-cellulose)
Hepta-nitro-cellulose - - C^H^O.^NOo)- = 10.19 ., ,,
Hexa-nitro-cellulose - - C.74H34O2o(NOo)r) = 9.17 ,. ,,
Penta-nitro-cellulose - C24H85O20(NO2):; = 8.04 ,, „
Tetra-nitro-cellulose - C24H36Oo0(NC>2)4 ^-6.77 ,,
( = old mono-nitro-cellulose)
It is not unlikely that a long series of nitrates exists. It
is at any rate certain that whatever strength of acids may
be used, and whatever temperature or other conditions may
be present during the nitration, that the product formed
always consists of a mixture of the soluble and insoluble
nitro-cellulose.
Theoretically 100 parts of cotton by weight should
produce 218.4 parts of gun-cotton, but in practice the
yield is a good deal less, both in the case of gun-cotton or
collodion-cotton. In speaking of soluble and insoluble
nitro-cellulose, it is their behaviour, when treated with a
solution consisting of 2 parts ether and I of alcohol, that
is referred to. There is, however, another very important
difference, and that is their different solubility in nitro-
glycerine. The lower nitrates or soluble form is soluble in
nitro-glycerine under the influence of heat, a temperature
of about 50° C. being required. At lower temperatures
the dissolution is very imperfect indeed ; and after the
materials have been left in contact for days, the threads of
the cotton can still be distinguished. The insoluble form
or gun-cotton is entirely insoluble in nitro-glycerine. It
can, however, be made to dissolve* by the aid of acetone or
acetic ether. Both or rather all the forms of nitro-cellulose
can be dissolved in acetone or acetic ether. They also
* Or rather to form a transparent jelly.
NITRO-CELLULOSES. 53
dissolve in concentrated sulphuric acid, and the penta-nitrate
in nitric acid at about 80° or 90° C.
The penta-nitrate may be obtained in a pure state by
the following process, devised by Eder : — The gun-cotton
is dissolved in concentrated nitric acid at 90° C., and re-
precipitated by the addition of concentrated sulphuric
acid. After cooling to o° C., and mixing with a larger
volume of water, the precipitated nitrate is washed with
water, then with alcohol, dissolved in ether-alcohol, and
again precipitated with water, when it is obtained pure.
This nitrate is soluble in ether-alcohol, and slightly in
acetic acid, easily in acetone, acetic ether, and methyl-
alcohol, insoluble in alcohol. Strong potash (KOH)
solution converts into the di-nitrate C12H18O8(NO3)2. The
hexa-nitrate is not soluble in acetic acid or methyl-alcohol.
The lower nitrates known as the tetra- and tri-nitrates
are formed together when cellulose is treated with a
mixture of weak acids, and allowed to remain in contact
with them for a very short time (twenty minutes). They
cannot be separated from one another, as they all dissolve
equally in ether-alcohol, acetic ether, acetic acid, methyl-
alcohol, acetone, amyl acetate, &c.
As far as the manufacture of explosive bodies is con-
cerned, the two forms of nitro-cellulose used and manu-
factured are gun-cotton or the hexa-nitrate (once regarded
as tri-nitro-cellulose), which is also known as insoluble gun-
cotton, and the soluble form of gun-cotton, which is also
known as collodion, and consists of a mixture of several of
the lower nitrates. It is probable that it chiefly consists,
however, of the next highest nitrate to gun-cotton, as the
theoretical percentage of nitrogen for this body, the
penta-nitrate, is 12.75 per cent, and analyses of com-
mercial collodion-cotton, entirely soluble in ether-alcohol,
often give as high a percentage as 12.6.
We shall only describe the manufacture of the two
forms known as soluble and insoluble, and shall refer to
them under their better known names of gun-cotton and
54 NITRO-EXPLOSIVES.
collodion-cotton. The following would, however, be the
formulae* and percentage of nitrogen of the complete
series : —
Hexa-nitro- cellulose CwH14D4(NOj)a 14. 14 per cent, nitrogen.
Penta-nitro-cellulose - ClaH18O5(NOs)6 12.75 » »
Tetra-nitro-cellulose C1:,H16O6(NO3)4 n.ii ,, ,,
Tri-nitro -cellulose C12H17O7(NO3)3 9.13 ,, ,,
Di-nitro-cellulose C12H18O8(NO3)a 7.65
Mono-nitro-cellulose C12Hj9O9(NO3) 3.80
Properties of Gun-Cotton. — The absolute density of
gun-cotton is 1.5. When in lumps its apparent density
is o.i ; if twisted into thread, 0.25 ; when subjected, in the
form of pulp, to hydraulic pressure, i.o to 1.4. Gun-cotton
preserves the appearance of the cotton from which it is
made. It is, however, harsher to the touch ; it is only
slightly hygroscopic (dry gun-cotton absorbs 2 per cent,
of moisture from the air). It possesses the property of
becoming electrified by friction. It is soluble in acetic
ether, amyl acetate, and acetone, insoluble in water, alcohol,
ether, ether-alcohol, methyl-alcohol, &c. It is very explo-
sive, and is ignited by contact with an ignited body, or by
shock, or when it is raised to a temperature of 172° C.
It burns with a yellowish flame, almost without smoke,
and leaves little or no residue. The volume of the gases
formed is large, and consists of carbonic acid, carbonic
oxide, nitrogen, and water gas. Compressed gun-cotton
when ignited often explodes when previously heated to
100° C.
Gun-cotton kept at 80° to 100° C. decomposes slowly,
and sunlight causes it to undergo a slow decomposition.
It can, however, be preserved for years without under-
going any alteration. It is very susceptible to explosions
by influence. For instance, a torpedo, even placed at a
* Berthelot takes C^H^O^o as the formula of cellulose ; and M.
Vieille regards the highest nitrate as (Co4H18(NO3H)1]O9). Compt.
Rend., 1882, p. 132.
PROPERTIES OF GUN-COTTON. 55
long distance, may explode a line of torpedoes charged
with gun-cotton. The velocity of the propagation of the
explosion in metallic tubes rilled with pulverised gun-
cotton has been found to be from 5,000 to 6,000 mms. per
second in tin tubes, and 4,000 in leaden tubes (Sebert).
Gun-cotton loosely exposed in the open air burns
eight times as quickly as powder (Piobert). A thin disc
of gun-cotton may be fired into from a rifle without
explosion ; but if the thickness of the disc be increased,
an explosion may occur. The effect of gun-cotton in
mines is very nearly the same as that of dynamite for
equal weights. It requires, however, a stronger detonator,
and it gives rise to a larger quantity of carbonic oxide
gas. Gun-cotton should be neutral to litmus, and should
stand the Government heat test — temperature of 150° F.
for fifteen minutes (see page 249). In the French Navy
gun-cotton is submitted to a heat test of 65° C. (= 149° F.)
for eleven minutes. It should contain as small a per-
centage of soluble nitro-cotton and of non-nitrated cotton
as possible.
The products of perfectly detonated gun-cotton may
be expressed by the following equation : —
2C12H1404(N03)6 = i8CO + 6C02+ i4H2O+ I2N.
It does not therefore contain sufficient oxygen for the
complete combustion of its carbon. It is for this reason
that when used for mining purposes a nitrate is gene-
rally added to supply this defect (as, for instance, in
tonite). It tends also to prevent the evolution of the
poisonous gas, carbonic oxide. The success of the various
gelatine explosives is due to this fact, viz., that the nitro-
glycerine has an excess of oxygen, and the nitro-cotton
too little, and thus the two explosives help one another.
In practice the gases resulting from the explosion of
gun-cotton are — Carbonic oxide, 28.55 ; carbonic acid,
19.11 ; marsh gas (CH4), 11.17; nitric oxide, 8.83; nitro-
gen, 8.56; water vapour, 21.93 per cent. The late Mr
56 NITRO-EXPLOSIVES.
E. O. Brown, of Woolwich Arsenal, discovered that per-
fectly wet and uninflammable compressed gun-cotton
could be easily detonated by the detonation of a priming
charge of the dry material in contact with it. This ren-
dered the use of gun-cotton very much safer for use as a
military or mining explosive.
As a mining explosive, however, gun-cotton is now
chiefly used under the form of tonite, which is a mixture
of half gun-cotton and half barium nitrate. This material
is sometimes spoken of as " nitrated gun-cotton." The
weight of gun-cotton required to produce an equal effect
either in heavy ordnance or in small arms is to the weight
of gunpowder in the proportion of I to 3, t.e.y an equal
weight of gun-cotton would produce three times the effect
of gunpowder. Its rapidity of combustion, however,
requires to be modified for use in firearms. Hence the
lower nitrates are generally used, or such compounds as
nitro-lignose, nitrated wood, &c., are used.
The initial pressure produced by the explosion of gun-
cotton is very large, equal to 18,135 atmospheres, and 8,740
kilogrammes per square centimetre for I kilo., the heat
liberated being 1,075 calories (water liquid), or 997.7 cals.
(water gaseous), but the quantity of heat liberated changes
with the equation of decomposition. According to Berthe-
lot,* the heat of formation of collodion-cotton is 696 cals.
for 1,053 grms-> or 66 1 cals. for I kilo. The heat liberated
in the total combustion of gun-cotton by free oxygen at
constant pressure is 2,633 cals. for 1,143 grms., or for I kilo,
gun-cotton 2,302 cals. (water liquid), or 2,177 C3^s- (water
gaseous). The heat of decomposition of gun-cotton in a
closed vessel, found by experiment at a low density of
charge (0.023), amounts to 1,071 cals. for I kilo, of the
substance, dry and free from ash. To obtain the maximum
effect of gun-cotton it must be used in a compressed state,
for the initial pressures are thereby increased. Wet gun-
*" Explosives and their Power," trans, by Hake and M'Nab.
MANUFACTURE OF GUN-COTTON. 57
cotton is much less sensitive to shock than dry. Paraffin
also reduces its liability to explode, so also does camphor.
The substance known as celluloid, a variety of nitro-
cellulose nearly corresponding to the formula C24H24
(NO8H)8O12, to which camphor and various inert sub-
stances are added, so as to render it non-sensitive to shock,
may be worked with tools, and turned in the lathe in the
same manner as ivory, instead of which material celluloid
is now largely used for such articles as knife handles,
combs, &c. Celluloid is very plastic when heated towards
150° C., and tends to become very sensitive to shock, and
in large quantities might become explosive during a fire,
owing to the general heating of the mass, and the con-
sequent evaporation of the camphor. When kept in the
air bath at 135° C., celluloid decomposes quickly. In an
experiment (made by M. Berthelot) in a closed vessel at
135° C., and the density of the charge being 0.4, it ended in
exploding, developing a pressure of 3,000 kilos. A large
package of celluloid combs also exploded in the guard's
van on one of the German railways a few years ago.
Although it is not an explosive under ordinary circum-
stances, or even with a powerful detonator, considerable
care should be exercised in its manufacture.
The Manufacture of Gun-Cotton. — The method used
for the manufacture of gun-cotton is that of Abel (Spec.
No. 1102, 20. 4. 65). It was worked out chiefly at Stow-
market* and Waltham Abbey,f but has in the course of
time undergone several alterations. These modifications
have taken place, however, chiefly upon the Continent, and
relate more to the apparatus and machinery used than to
any alteration in the process itself. The form of cellulose
used is cotton -waste,J which consists of the clippings and
* The New Explosive Co. Works.
t Royal Gunpowder Factory.
I Costs from ^10 to ^25 a ton. In his description of the "Pre-
paration of Cotton-waste for the Manufacture of Smokeless Powder,'
58 NITRO-EXPLOSIVES.
waste material from cotton mills. After it has been cleaned
and purified from grease, oil, and other fatty substances by
treatment with alkaline solutions, it is carefully picked over,
and every piece of coloured cotton rag or string carefully
removed. The next operation to which it is submitted has
for its object the opening up of the material. For this
purpose it is put through a carding machine, and afterwards
through a cutting machine, whereby it is reduced to a state
suitable for its subsequent treatment with acids, that is,
it has been cut into short lengths, and the fibres opened
up and separated from one another.
Drying the Cotton. — This operation is performed in
either of two ways. The cotton may either be placed upon
shelves in a drying house, through which a current of hot
air circulates, or dried in steam-jacketed cylinders. It is
very essential that the cotton should be as dry as possible
before dipping in the acids, especially if a wholly "insoluble"
nitro-cellulose is to be obtained. After drying it should
not contain more than 0.5 per cent, of moisture, and less
than this if possible. The more general method of drying
the cotton is in steam-jacketed tubes, '/'.£., double cylinders
of iron, some 5 feet long and U foot wide. The cotton is
placed in the central chamber (Fig. 10), while steam is
made to circulate in the surrounding jacket, and keeps the
whole cylinder at a high temperature (steam pipes may be
A. Hertzog states that the German military authorities require a
cotton which when thrown into water sinks in two minutes ; when
nitrated, does not disintegrate ; when treated with ether, yields only
0.9 per cent, of fat ; and containing only traces of chlorine, lime,
magnesia, iron, sulphuric acid, and phosphoric acid. If the cotton is
very greasy, it must be first boiled with soda-lye under pressure,
washed, bleached with chlorine, washed, treated with sulphuric acid or
HC1, again washed, centrifugaled, and dried ; if very greasy indeed a
preliminary treatment with lime-water is desirable. See also " Inspec-
tion of Cotton-Waste for Use in the Manufacture of Gun-cotton," by
C. E. Munro,/0«r. Am. Chem. Soc., 1895, :7> 783-
DRYING THE COTTON.
59
coiled round the outside of an iron tube, and will answer
equally well). By means of a pipe which communicates
with a compressed air reservoir, a current of air enters at the
bottom, and finds its way up through the cotton, and helps
to remove the moisture that it contains. The raw cotton
generally contains about 10 per cent, of moisture and
should be dried until it contains only <\ fl /?
J per cent, or less. For this it will
generally have to remain in the dry-
ing cylinder for about five hours. At
the end of that time a sample should
be taken from the top of the cylinder,
and dried in the water oven(ioo° C.*)
for an hour to an hour and a half, and
re-weighed, and the moisture then re-
maining in it calculated.
It is very convenient to have a
large copper water oven, containing a
lot of small separate compartments,
large enough to hold about a handful
of the cotton, and each compartment
numbered, and corresponding to one of the drying cylinders.
The whole apparatus should be fixed against the wall of
the laboratory, and may be heated by bringing a small
steam pipe from the boiler-house. It is useful to have a
series of copper trays, about 3 inches by 6 inches, numbered
to correspond to the divisions in the steam oven, and exactly
fitting them. These trays can then be taken by a boy to
the drying cylinders, and a handful of the cotton from each
placed in them, and afterwards brought to the laboratory
and weighed (a boy can do this very well), placed in their
respective divisions of the oven, and left for one to one and
a half hours, and re-weighed.
When the cotton is found to be dry the bottom of the
•«=5
FIG. 10. — COTTON DRIER.
* It is dried at 180° C. at Waltham Abbey, in a specially con-
structed drying chamber.
60 NITRO-EXPLOSIVES.
drying cylinder is removed, and the cotton pushed out
from the top by means of a piece of flat wood fixed on a
broom-handle. It is then packed away in galvanised-iron
air-tight cases, and is ready for the next operation. At
some works the cotton is dried upon shelves in a drying
house through which hot air circulates, the shelves being of
canvas or of brass wire netting. The hot air must pass
under the shelves and through the cotton, or the process
will be a very slow one.
Dipping" and Steeping. — The dry cotton has now to
be nitrated. This is done by dipping it into a mixture of
nitric and sulphuric acids. The acids used must be strong,
that is, the nitric acid must be at least of a gravity of 1.53
to 1.52, and should contain as little nitric oxide as possible.
The sulphuric acid must have a specific gravity of 1.84 at
15° C, and contain about 97 per cent, of the mono-hydrate
(H2SO4). In fact, the strongest acids obtainable should be
used when the product required is gun-cotton, i.e., the
highest nitrate.
The sulphuric acid takes no part in the chemical re-
action involved, but is necessary in order to combine with
the water that is liberated in the reaction, and thus to main-
tain the strength of the nitric acid. The reaction which
takes place is the following : —
324 378 = 594 1 08.
Cellulose. Gun-Cotton.
Theoretically,* therefore, I part of cellulose should form
1.8 part of gun-cotton. Practically, however, this is never
obtained, and 1.6 Ib. from I Ib. of cellulose is very good
working. The mixture of acids used is generally I to 3,
or 25 per cent, nitric acid to 75 per cent, sulphuric acid.
* 594X1=I.83.
324 J
STEEPING THE COTTON.
6l
The dipping is done in cast-iron tanks (Fig. 1 1), a series
of which is arranged in a row, and cooled by a stream of
FIG. ii.— TANK FOR DIPPING COTTON.
cold water flowing round them. The tanks hold about
12 gallons, and the cotton is dipped in portions of I Ib. at
a time. It is thrown into the acids, and the workman
FIG. i2.— THE COOLING PITS.
moves it about for about three minutes with an iron rabble.
At the end of that time he lifts it up on to an iron grating,
62
NITRO-EXPLOSIVES.
just above the acids, fixed at the back of the tai)k, where
by means of a movable lever he gently squeezes it, until it
contains about ten times its weight of acids (the I Ib. weighs
10 Ibs.). It is then transferred to earthenware pots to steep.
Steeping. — The nitrated cotton, when withdrawn from
the dipping tanks, and still containing an excess of acids,
is put into earthenware pots of the shape shown in Figs.
12 and 13. The lid is put on, and the pots placed in rows
in large cooling pits, about a foot deep,
through which a stream of water is con-
stantly flowing. These pits form the floor
of the steeping house. The cotton remains
in these pots for a period of forty-eight
hours, and must be kept cool. Between
FIG. 13. — COTTOX
STEEPING POT. i g° and 19° C. is the highest temperature
desirable, but the cooler the pots are kept the better. At
the end of forty-eight hours the chemical reaction is com-
EERS
INCHAM
FIG. 14. — HYDRO-EXTRACTOR.
plete, and the cotton is or should be wholly converted into
nitro-cellulose ; that is, there should be no unnitrated cotton.
Whirling1 Out the Acid. — The next operation is to
remove the excess of acid. This is done by placing the
WASHING GUN-COTTON. 63
contents of two or three or more pots into a centrifugal
hydro-extractor (Fig. 14), making 1,000 to 1,500 revolutions
per minute. The hydro-extractor consists of a machine
with both an inner cylinder and an outer one, both revolv-
ing in concert and driving outwardly the liquid to the
chamber, from which it runs away by a discharge pipe.
The wet cotton is placed around the inner cone. The
cotton, when dry, is removed, and at once thrown into a
large tank of water, and the wraste acids are collected in
a tank.*
Washing1. — The cotton has now to be carefully washed.
This is done in a large wooden tank filled with water. If,
however, a river or canal runs through the works, a series
of wooden tanks, the sides and bottoms of which are pierced
with holes, so as to allow of the free circulation of water,
should be sunk into a wooden platform that overhangs
the surface of the river in such a way that the tanks are
immersed in the water, and of course always full. During
the time that the cotton is in the water a workman turns it
over constantly with a wooden paddle. A stream of water,
in the form of a cascade, should be allowed to fall into
these tanks. The cotton may then be thrown on to this
stream of water, which, falling some height, at once carries
the cotton beneath the surface of the water. This pro-
ceeding is necessary because the cotton still retains a large
excess of strong acids, and when mixed with water gives
rise to considerable heat, especially if mixed slowly with
water. After the cotton has been well washed, it is again
* Care must be taken in hot weather that the gun-cotton does not
fire, as it does sometimes, directly the workman goes to remove it
after the machine is stopped. It occurs more often in damp weather.
Dr Schiipphaus, of Brooklyn, U.S.A., proposes to treat the waste
acids from the nitration of cellulose by adding to them sulphuric
anhydride and nitric acid. The sulphuric anhydride added converts
the water liberated from the cellulose into sulphuric acid.
64
NITRO-EXPLOSIVES.
wrung out in a centrifugal machine, and afterwards allowed
to steep in water for some time.
Boiling. — The washed cotton is put into large iron
boilers with plenty of water, and boiled for some time at
1 00° C. In some works lead-lined tanks are used, into
which a steam pipe is led. The soluble impurities of un-
FIG. 15/2. — THE BEATER FOR GUN-COTTON.
stable character, to which Sir F. A. Abel traced the liability
of gun-cotton to instability, are thereby removed. These
impurities consist of the products formed by the action of
nitric acid on the fatty and resinous substances contained
in the cotton fibres. The water in the tanks should be
every now and again renewed, and after the first few
boilings the water should be tested with litmus paper until
they are no longer found to be acid.
PULPING GUN-COTTON. 65
Pulping. — The idea of pulping is also due to Abel. By
its means a very much more uniform material is obtained.
The process is carried out in an apparatus known as a
" Beater" or " Hollander" (Fig. 15, a, b). It consists of a
kind of wooden tank some 2 or 3 feet deep of an oblong
shape, in which a wheel carrying a series of knives is made
to revolve, the floor of the tank being sloped up so as to
almost touch the revolving wheels. This part of the floor,
known as the " craw," is a solid piece of oak, and a box of
knives is fixed into it, against which
the knives in the revolving wheel are
pressed. The beater is divided into
two parts — the working side, in which
the cotton is cut and torn between the Fl& X^_WHEEL OF BEATER.
knife edges in the revolving cylinder
and those in the box ; and the running side, into which the
cotton passes after passing under the cylinder. The wheel
is generally boxed in to prevent the cotton from being
thrown out during its revolution. The cotton is thus in
constant motion, continually travelling round, and passing
between the knives in the revolving cylinder and those in
FIG. i6a. — POACHER FOR WASHING GUN-COTTON.
the box fixed in the wooden block beneath it. The beater
is kept full of water, and the cotton is gradually reduced to
a condition of pulp. The wheel revolves at the rate of 100
to 150 times a minute.
When the gun-cotton is judged to be sufficiently fine,
the contents of the beater are run into another very similar
piece of machinery, known as the " poacher " (Fig. 16, a, £, c\
E
66
NITRO-EXPLOSIVES.
in which the gun-cotton is continuously agitated together
with a large quantity of water, which can be easily run off
and replaced as often as required. When the material is
first run into the poacher from the beater, the water with
FIG. i63. — PLAN OF THE POACHER.
which it is then mixed is first run away and clean water
added. The paddle wheel is then set in motion, and at
intervals fresh water is added. There is a strainer at the
bottom of the poacher which enables the water to be drawn
off without disturbing the cotton pulp. After the gun-
FIG. i6c. — ANOTHER FORM OF POACHER.
cotton has been in the poacher for some time, a sample
should be taken by holding a rather large mesh sieve in
the current for a minute or so. The pulp will thus partly
pass through and partly be caught upon the sieve, and an
average sample will be thus obtained. The sample is
COMPRESSING GUN-COTTON. 67
squeezed out by hand, bottled, and taken to the laboratory
to be tested by the heat test for purity. It first, however,
requires to be dried. This is best done by placing the
sample between coarse filter paper, and then putting it
under a hand-screw press, where it can be subjected to a
tolerably severe pressure for about three minutes. It is
then rubbed up very finely with the hands, and placed upon
a paper tray, about 6 inches by 4-| inches, which is then
placed inside a water oven upon a shelf of coarse wire
gauze, the temperature of the oven being kept as near as
possible to 120° F. (49° C.), the gauze shelves in the oven
being kept about 3 inches apart. The sample is allowed
to remain at rest for fifteen minutes in the oven, the door
of which is left wide open. After the lapse of fifteen minutes
the tray is removed and exposed to the air of the laboratory
(away from acid fumes) for two hours, the sample being at
some point within that time rubbed upon the tray with the
hand, in order to reduce it to a fine and uniform state of
division. Twenty grains (1.296 grm.) are used for the
test. (See Heat Test, page 249.)
If the gun-cotton sample removed from the poacher
stands the heat test satisfactorily, the machine is stopped,
and the water drained off. The cotton is allowed some
little time to drain, and is then dug out by means of
wooden spades, and is then ready for pressing. The
poachers hold about 2,000 Ibs. of material, and as this
represents the products of many hundred distinct nitrating
operations, a very uniform mixture is obtained. Two
per cent, of carbonate of soda is sometimes added, but
it is not really necessary if the cotton has been properly
washed.
Compressing Gun-Cotton. — The gun-cotton, in the
state in which it is removed from the poacher, contains
from 28 to 30 per cent, of water. In order to remove this,
the cotton has to be compressed by hydraulic power. The
dry compressed gun-cotton is packed in boxes containing
68
NITRO-EXPLOSIVES.
2,500 Ibs. of dry material. In order to ascertain how much
of the wet cotton must be put into the press, it is necessary
to determine the percentage of water. This may be done
by drying 2,000 grains upon a paper tray (previously dried
at 1 00° C.) in the water oven at 100° C. for three hours,
and re-weighing and calculating the percentage of water.
It is then easy to calculate how much of the wet gun-cotton
must be placed in the hopper of the press in order to
obtain a block of compressed cotton of the required weight.
FIG. 17. — OLD METHOD. 100 PIECES.
FIG. 18. — NEW METH6o. ONE SOLID F>LOCIC.
Various forms of presses are used, and gun-cotton is sent
out either as solid blocks, compressed discs, or in the form
of an almost dry powder, in zinc-lined, air-tight cases. The
discs are often soaked in water after compression until they
have absorbed 25 per cent, of moisture.
At the New Explosives Company's Stowmarket Works
large solid blocks of gun-cotton are pressed up under a new
process, whereby blocks of gun-cotton, for use in submarine
mines or in torpedo warheads, are produced. Large charges
COMPRESSING GUN-COTTON. 69
of compressed gun-cotton have hitherto been built up from
a number of suitably shaped charges of small dimensions
(Fig. 17), as it has been impossible to compress large
charges in a proper manner. The formation of large-sized
blocks of gun-cotton was the invention of Mr A. Rollings.
Prior to the introduction of this method, 8 or 9 Ibs. had
been the limit of weight for a block. This process has
been perfected at the Stowmarket factory, where blocks
varying from the armour-piercing shell charge of a few
ounces up to blocks of compressed gun-cotton mechanically
true, weighing 4 to 5 cwts. for torpedoes or submarine mines,
are now produced. At the same time the new process
ensures a uniform density throughout the block, and per-
mits of any required density, from 1.4 downwards, being
attained ; it is also possible exactly to regulate the per-
centage of moisture, and to ensure its uniform distribution.
The maximum percentage of moisture depends, of course,
upon the density. By the methods of compression gun-
cotton blocks hitherto employed, blocks of a greater thick-
ness than 2 inches, or of a greater weight than 9 Ibs., could
not be made, but with the new process blocks of any shape,
size, thickness, or weight that is likely to be required can
be made readily and safely. The advantages which are
claimed for the process may be enumerated as follows : —
(i.) There is no space wasted, as in the case with built-up
charges, through slightly imperfect contact between the
individual blocks, and thus either a heavier charge — i.e.,
about 15 per cent, more gun-cotton — can be got into the
same space, or less space will be occupied by a charge of a
given weight. (2.) The metallic cases for solid charges may
be much lighter than for those built-up, since with the
former their function is merely to prevent the loss of
moisture from wet gun-cotton, or to prevent the absorption
of moisture by dry gun-cotton. They can thus be made
lighter, as the solid charge inside will prevent deformation
during transport. With built-up charges the case must be
strong enough to prevent damage, either to itself or to the
7O NITRO-EXPLOSIVES.
charge it contains. For many uses a metal case, however
light, may be discarded, and one of a thin waterproof
material substituted. (3.) The uniform density of charges
made by this process is very favourable to the complete
and effective detonation of the entire mass, and to the
presence of the uniform amount of moisture in every part of
the charge. (4.) Any required density, from the maximum
FIG. 19. — A 4-Cwr. BLOCK OF GUN-COTTON BEING TAKEN FROM HYDRAULIC PRESS.
downwards, may be obtained with ease, and any required
amount of moisture left in the charge. These points are of
great importance in cases where, like torpedo charges, it is
essential to have the centre of gravity of the charge in a
predetermined position both vertically and longitudinally,
and the charge so fixed in its containing case that the
centre of gravity cannot shift. The difficulty of ensuring
this with a large torpedo charge built up from a number
WALTHAM ABBEY PROCESS. /I
of discs and segments is well known. Even with plain
cylindrical or prismatic charges a marked saving in the
process of production is effected by this new system. The
charges being in one block they are more easily handled
for the usual periodical examination, and they do not break
or chafe at the edges, as in the case of discs and cubes in
built-up charges. A general view of the press is given in
Fig. 19. The gun-cotton in a container is placed on a
cradle fixed at an angle to the press. The mould is
swivelled round, and the charge pushed into it with a
rammer, and it is then swivelled back into position. The
mould is made up of a number of wedge pieces which close
circumferentially on the enclosed mass, which is also sub-
jected to end pressure. Holes are provided for the escape
of water.
The Waltham Abbey Process.— At the Royal Gun-
powder Factory, Waltham Abbey, the manufacture of gun-
cotton has been carried out for many years. The process
used differs but little from that used at Stowmarket. The
cotton used is of a good quality, it is sorted and picked
over to remove foreign matters, &c., and is then cut up by
a kind of guillotine into 2-inch lengths. It is then dried in
the following manner. The cotton is placed upon an end-
less band, which conducts it to the stove, or drying closet,
a chamber heated by means of hot air and steam traps to
about 1 80° F. ; it falls upon a second endless band, placed
below the first ; it travels back again the whole length of
the stove, and so on until delivered into a receptacle at the
bottom of the farther end, where it is kept dry until
required for use. The speed at which the cotton travels
is 6 feet per minute, and as the length of the band travelled
amounts to 1 26 feet, the operation of drying takes twenty-
one minutes. One and a quarter Ib. are weighed out and
placed in a tin box ; a truck, fitted to receive a number of
these boxes, carries it along a tramway to a cool room,
where it is allowed to cool.
72 NITRO-EXPLOSIVES.
Dipping. — Mixed acids are used in the proportion of
i to 3, specific gravity nitric acid 1.52, and sulphuric acid
1.84. The dipping tank is made of cast iron, and holds
220 Ibs. of mixed acids, and is surrounded on three sides
by a water space in order to keep it cool. The mixed acids
are stored in iron tanks behind the dipping tanks, and are
allowed to cool before use. During the nitration, the
temperature of the mixed acids is kept at 70° R, and the
cotton is dipped in quantities of I J Ib. at a time. It is put
into a tin shoot at the back of the dipping tank, and raked
into the acids by means of a rabble. It remains in the
acids for five or six minutes, and is then removed to a
grating at the back, pressed and removed. After each
charge of cotton is removed from the tank, about 14 Ibs. of
fresh mixed acids are added, to replace amount removed
by charge. The charge now weighs, with the acids retained
by it, 1 5 Ibs. ; it is now placed in the pots, and left to steep
for at least twenty-four hours, the temperature being kept
as low as possible, to prevent the formation of soluble
cotton, and also prevent firing. The proportion of soluble
formed is likely to be higher in hot weather than cold.
The pots must be covered to prevent the absorption of
moisture from the air, or the accidental entrance of water,
which would cause decomposition, and consequent fuming
off, through the heat generated by the action of the water
upon the strong acids.
The excess of acids is now extracted by means of
hydro-extractors, as at Stowmarket. They are worked at
1,200 revolutions per minute, and whirled for five minutes
(io| Ibs. of waste acids are removed from each charge
dipped). The charge is then washed in a very similar
manner to that previously described, and again wrung out
in a centrifugal extractor (1,200 revolutions per minute).
The gun-cotton is now boiled by means of steam in wooden
tanks for eight hours ; it is then again wrung out in the
extractors for three minutes, boiled for eight hours more,
and again wrung out ; it is then sent to the beater and
THOMSON'S GUN-COTTON PROCESS. 73
afterwards to the poacher. The poachers hold 1,500 gals,
each, or 18 cwt. of cotton. The cotton remains six hours
in the poachers. Before moulding, 500 gals, of water are
run into the poacher, and 500 gals, of lime water containing
9 Ibs. of whiting and 9 gals, of a caustic soda solution.
This mixture is of such a strength that it is calculated to
leave in the finished gun-cotton from I to 2 per cent, of
alkaline matter.
By means of vacuum pressure, the pulp is now drawn
off and up into the stuff chest — a large cylindrical iron
tank, sufficiently elevated on iron standards to allow room
for the small gauge tanks and moulding apparatus below.
It holds the contents of one poacher (18 cwt.), and is
provided with revolving arms to keep the pulp stirred
up, so that it may be uniformly suspended in water.
Recently a new process, invented by J. M. and W. T.
Thomson (Eng. Pat. No. 8,278, 1903), has been introduced
at the Waltham Abbey Factory. The object of this inven-
tion is the removal of the acids of nitration from the nitrated
material after the action has been completed, and without the
aid of moving machinery,such as presses, rollers, centrifugals,
and the like. The invention consists in the manufacture
of nitrated celluloses by removing the acids from the nitrated
cellulose directly by displacement without the employment
of either pressure or vacuum or mechanical appliances of
any kind, and at the same time securing the minimum
dilution of the acids. It was found that if water was care-
fully run on to the surface of the acids in which the nitro-
cellulose is immersed, and the acids be slowly drawn off at
the bottom of the vessel, the water displaces the acid from
the interstices of the mtro-cellulose without any undesirable
rise in temperature, and with very little dilution of the acids.
By this process almost the whole of the acid is recovered
in a condition suitable for concentration, and the amount
of water required for preliminary washing is very greatly
reduced. The apparatus which is used for the purpose
consists of a cylindrical or rectangular vessel constructed
74
NITRO-EXPLOSIVES.
with a perforated false bottom and a cock at its lowest
point for running off the liquid. Means are also provided
to enable the displacing water to be run quietly on to the
surface of the nitrating acids.*
The apparatus is shown in Fig. 20, side elevation, and
in Fig. 21 a plan of the nitrating vessel and its accessories
FIG. 20. — SECTIONAL ELEVATION OF THOMSON'S APPARATUS, a, Tank ; b, False
Bottom ; c, Bottom ; c ', Ribs ; d, Draining Outlet ; c, Grid ; /, Troughs, with
Aprons £•; h, Pipe, with Branches h', leading to Troughs/"; &', Outlet Pipe of the
Sulphuric Acid Tank k ; /, Water Supply Pipe ; m, Pipe to supply of Nitrating
Acids ; o, Perforations of Trough/; /, Cock to remove Acid.
is given. In Fig. 20 is shown in sectional elevation one
of the trough devices for enabling liquids to be added to
those in the nitrating vessel without substantial disturbance.
In carrying out this invention a rectangular lead-lined
or earthenware tank a is employed, having a false bottom
b, supported by ribs c\ over the real bottom c, which slopes
down to a draining outlet pipe d, provided with a perforated
* In a further patent (Eng. Pat. 7,269, 1903, F. L. Natham), J. M.
Thomson and W. T. Thomson propose by use of alcohol to replace
the water, used in washing nitro-cellulose, and afterward to remove
the alcohol by pressing and centrifuging.
THOMSON'S APPARATUS.
75
grid or plate <?, adapted to prevent choking of the outlet.
Suitably supported near the top of the vessel a are pro-
vided two troughs/; having depending aprons g, a pipe h
has two branches h\ leading to the troughs/] This pipe h
is adapted to be connected by a rubber pipe either to the
outlet pipe k' of the sulphuric acid tank k or the water
supply pipe /. The nitrating acids are supplied through
the pipe m. A charge of mixed nitrating acids is introduced
into the vessel a say up to the level n, and the dry cellulose
FIG. 21.— PLAN OF THOMSON'S APPARATUS, a, Tank ; £, False Bottom ; c', Ribs ; e,
Grid;/", Troughs;^-, Aprons; h and h', Pipes to Troughs/"; /£, Sulphuric Acid
Tank ; m, Pipe to Nitrating Acids Tank ; o, Perforations of Troughs ; /, Cock to
remove Acid.
thrown into the acids in small quantities at a time, being
pushed under the surface in the usual way.
A thin layer, say half an inch, of a suitable liquid,
preferably sulphuric acid, of a gravity not exceeding that
of the waste acid to be produced, is run carefully on the
top of the acids by means of the troughs f, which are
perforated as shown at 0, so that the sulphuric acid runs
down the aprons g, and floats on the nitrating acids. The
76 NITRO-EXPLOSIVES.
whole is then allowed to stand till nitration has been com-
pleted. Water is then supplied to the troughs by way of
the pipes /, ^, and //, and is allowed to float very gently
over the surface of the sulphuric acid, and when a sufficient
layer has been formed, the cock p at the bottom of the
apparatus is opened, and the acid slowly drawn off, water
being supplied to maintain the level constant. It is found
that the rate of displacement of the acids is a factor which
exerts a considerable influence on the properties of the
resulting nitro-cellulose, and affords a means of regulating
the temperature of displacement. A rate of displacement
which has been found suitable is about two inches in depth
of the vessel per hour when treating highly nitrated cellu-
loses, but this rate may, in some cases, be considerably
increased. The flow of water at the top of the apparatus
is regulated so that a constant level is maintained. By
this means the water gradually and entirely displaces the
acids from the interstices of the nitro-cellulose, the line of
separation between the acids and the water being fairly
sharply defined throughout. The flow of water is continued
until that issuing at the bottom is found to be free from all
trace of acid. The purification of the nitro-cellulose is then
proceeded with as usual, either in the same vessel or another.
In the process above described, the object of the intro-
duction of a small layer of sulphuric acid is mainly to
prevent the fuming which would otherwise take place, and
is not essential, as it is found it can be omitted without any
deleterious effect. In order to use the mixed acids in the
most economical manner, the waste acid from a previous
operation may be used for a first nitration of the cellulose ;
being afterwards displaced with fresh acids which carry the
nitration to the required degree before they are in turn
displaced by water. The apparatus may be used merely
for the removal of the acid, in which case the nitration is
carried out in other vessels in the usual way, and the nitro-
cellulose removed to the displacement apparatus where it
is just covered with waste acid, and the displacement then
MOULDING AND COMPRESSING GUN-COTTON. 77
proceeded with as above described. In some cases the
process is carried out in an ordinary nitrating centrifugal,
using the latter to effect preliminary drying after acid
extraction. This gives a great advantage over the usual
method of working ordinary centrifugal nitrating apparatus,
because the acid being removed before the centrifugal is
run, practically all danger of firing therein disappears, and
a greater proportion of the waste acid is recovered.
In some cases the acids and water may be supplied
by perforated pipes, lying along the edges of the nitrating
vessel, and these edges may, if desired, be themselves made
inclined, like the sides of the troughs f. In the case of
effecting nitration in centrifugals as above, the displacing
sulphuric acid and water may thus be supplied round the
edges of the machines, or removal troughs such as /"may
be used. It will be obvious that any inert liquid of suitable
specific gravity may be used instead of sulphuric acid, as a
separation layer.
Moulding1. — By means of the small measuring tank
above referred to, the gun-cotton pulp is drawn ofif from
the stuff chest, and run into moulds of the shapes and sizes
required. Thence a large proportion of the water is drawn
off by means of tubes connected with the vacuum engine,
the moulds having bottoms of fine wire gauze, in order to
prevent the pulp from passing through. Hydraulic pressure
of about 34 Ibs. on the square inch is then applied, which
has the effect of compressing the pulp into a state in which
it has sufficient consistency to enable it to be handled with
care, and also expels a portion of the remaining water.
Compressing. — The moulded gun-cotton is now taken
to the press house, which is situated at some distance from
the rest of the factory. Here the moulds are subjected to
powerful hydraulic pressure, from 5 to 6 tons per square
inch, and is compressed to one-third of its previous bulk.
The slabs or discs thus formed are kept under pressure for
a short time, not exceeding a minute and a half, to give the
78 NITRO-EXPLOSIVES.
requisite density. It should, when removed, be compact,
and just sink in water, and should perceptibly yield to the
pressure of the fingers. There are perforations in the press
blocks, to allow of the escape of gases, if formed, by reason
of sufficient heat being generated. The men working the
press are placed under cover, behind strong rope mantlets
having eye tubes which command a view of the press.
Packing". — The finished slabs and discs are dipped into
a solution of soda and carbolic acid, and packed in special
wood metal-lined cases. When it is to be sent abroad, the
metal lining, which is made of tinned copper, is soldered
down, but both the outer wooden and inner metal cases are
fitted with air-tight screw-plugs, so that when necessary
water can be added without unfastening the cases.
Reworked gun-cotton does not make such good discs
as new pulped gun-cotton, probably because the fibrous
tenacity of the gun-cotton has been destroyed by the
amount of pressure it has previously undergone, so that
when repulped it resembles fine dust, and a long time is
required to press it into any prescribed form. It is generally
boiled for eight hours to open up the fibre and remove
alkali, then broken up by hand with wooden mallets,
pulped, and then used with fresh gun-cotton in the pro-
portion of I to 5 parts.
Manufacture at Le Bouchet. — At Le Bouchet gun-
cotton was made thus : — 200 grms. of cotton were steeped
for an hour in 2 litres of a mixture of I volume concentrated
nitric and 2 volumes sulphuric acid. The cotton was then
removed and pressed, whereby T7oths of the waste acids
was recovered. After this it was washed for one to one
and a half hours in running water, strongly pressed again ;
allowed to lie for twenty-four hours in wood-ash lye ; then
well washed in running water ; pressed, and finally dried
on a wide linen sheet, through which was forced air heated
to 60° C. The average yield from 100 parts of cotton was
GRANULATION OF GUN-COTTON. 79
165 parts of gun-cotton. The strong pressings of the gun-
cotton, while still impregnated with acids, caused sub-
sequent washings to be difficult and laborious.
Granulation of Gun-Cotton. — Gun-cotton is often
required in the granulated form for use either alone or with
some form of smokeless powder. This is done under the
patent of Sir Frederick Abel in the following manner : —
The gun-cotton from the poacher is placed in a centrifugal
machine, very similar to the hydro-extractors before men-
tioned, and used for wringing out the acids. In this
machine it loses water until it only contains 33 per cent.,
and is at the same time reduced to a more or less fibrous
state. It is then taken to the granulating room, where it is
first passed through sieves or perforations, which break up
the mass into little pieces like shot The material is then
transferred to a revolving drum made of wood or stout
leather, which is kept constantly revolving for some time.
The material is occasionally sprinkled with water. The
drum in turning, of course, carries the granules partially
round with it, but the action of gravity causes them to
descend constantly to the lowest point, and thus to roll
over one another continually. The speed of the drum
must not be too rapid. None of the granules must be
carried round by centrifugal force, but it must be fast
enough to carry them some little distance up the side of
the .drum. After removal from the drum the granules are
dried upon shelves in the drying house.
Gun-cotton is also dissolved in acetone or acetic ether
until it has taken the form of a jelly. It is then rolled into
thin sheets, and when dry cut up into little squares. In
the manufacture of smokeless powders from nitro-cellulose,
nitro-lignine, &c., the various substances are mixed with
the gun-cotton or collodion-cotton before granulating.
Collodion-Cotton. — In the manufacture of collodion or
soluble cotton the finer qualities of cotton-waste are used
80 NITRO-EXPLOSIVES.
and the acids used in the dipping tanks are much weaker.
The manufacture of collodion-cotton has become of more
importance than gun-cotton, by reason of its use for the
manufacture of the various forms of gelatine, such as
gelatine dynamite, gelignite, forcite, &c., and also on account
of its extensive use in the manufacture of many of the
smokeless powders. It is also used for the manufacture
of " collodion," which is a solution of collodion-cotton in
ether-alcohol ; for the preparation of celluloid, and many
other purposes. It is less explosive than gun-cotton, and
consists of the lower nitrates of cellulose. It is soluble in
nitro -glycerine, and in a mixture of 2 parts of ether and I
of alcohol ; also in acetone, acetic ether, and other solvents.
MM. Menard and Domonte were the first to prepare a
soluble gun-cotton, and its investigation was carried on by
Bechamp, who showed that its properties and composition
were different to those of gun-cotton.
Manufacture. — The cotton used is cotton-waste.* It
is thought by some that Egyptian cotton is preferable,
and especially long fibre varieties. The strength of the
acids used is, however, of more importance than the quality
of the cotton. The percentage composition of the acid
mixture which gives the best results is as follows : — Nitric
acid, 23 per cent. ; sulphuric acid, 66 per cent. ; and water,
II per cent ; and has a specific gravity of 1.712 (about).
It can be made by mixing sulphuric acid of specific gravity
1.84 with nitric acid of specific gravity 1.368 in the pro-
portions of 66 per cent, and 34 per cent, respectively.
(The production of the penta-nitro-cellulose is aimed at if
the collodion-cotton is for use as an explosive.) If the
acids are much weaker than this, or potassium nitrate and
sulphuric acid is used, the lower nitrates will be formed.
The product, while being entirely soluble in ether-alcohol
or nitro-glycerine, will have a low nitrogen content, whereas
* Raw cotton is often used.
COLLODION-COTTON. i
a material with as high a nitrogen as 12 or 12.6 is to be
aimed at.
The cotton should not be allowed to remain in the
dipping tanks for more than five minutes, and the acid
mixture should be kept at a temperature of 28° C. or
thereabouts ; and the cotton should be removed after a few
minutes, and should not be pressed out, as in the case of
gun-cotton, but at once transferred to the pots and allowed
to steep for forty-eight hours. (Some prefer twenty-four
hours, but there is more chance in this case of the product
containing non-nitrated cellulose.) When the nitration is
complete, the collodion-cotton is removed from the pots,
and treated in exactly the same manner as described under
gun-cotton. The produce should be entirely soluble in
ether-alcohol and nitro-glycerine, and contain as near
12.7 per cent, of nitrogen as possible. The theoretical
nitrogen is for the penta-nitro-cellulose 12.75 Per cent
This will, however, seldom if ever be obtained. The
following are some of the results I have obtained from
different samples : —
Nitrogen.
(I-) (2.) (3.)
German make 11.64 11.48 11.49 per cent.
Stowmarket - 12.57 12.60 11.22 „
Walsrode 11.61 12.07 H-99 „
Faversham - 12.14 n-7o n.6o „
and the following was the analysis of a sample (No. i) of
German-made collodion -cotton, which made very good
blasting gelatine : —
Soluble cotton (collodion) 99., ,8 per cent. ) m =
Gun-cotton - - - 0.642 „ )
Non-nitrated cotton - 0.240 „
Total ash - - - 0.25 „
It should contain as little non-nitrated or unconverted
cotton and as little gun-cotton as possible, as they are both
insoluble in nitro-glycerol. The quality and composition
of any sample of collodion-cotton can be quickly inferred
F
82 NITRO-EXPLOSIVES
by determining the percentage of nitrogen by means of the
nitrometer and the use of the solubility test.* A high
nitrogen content coupled with a high solubility is the end
to be aimed at ; a high nitrogen with a low solubility shows
the presence of gun-cotton, and a low nitrogen, together
with a low solubility, the presence of unnitrated cotton.
Where complete solubility is essential and the percentage
of nitrogen less important, Dr Lunge recommends nitra-
tion with a mixture of equal parts of sulphuric and nitric
acids containing from 19 to 20 per cent, of water.
Mr T. R. France claims to have invented some im-
provements in the manufacture of soluble nitro-cellulose.
His object has been to produce an article as uniform as
possible. His explanation of the imperfect action of the
acids is that, however uniform the mixed acids may be in
strength and proportions, and however carefully the opera-
tions of nitrating, &c., may be conducted, there are variable
elements found in different samples of cotton. The cotton
fibre has for its protection a glazed surface. It is tubular
and cellular in structure, and contains a natural semi-fluid
substance composed of oil or gum, which varies in nature
according to the nature of the soil upon which the cotton is
grown. The tubes of the fibre seem to be open at one end
only when the fibre is of normal length. When, therefore,
the cotton is subjected to the action of the mixed acids, the
line of least resistance seems to be taken by them, viz., the
insides of the tubes constituting the fibre of the cotton, into
which they are taken by capillary attraction, and are subject
to change as they progress, and to the increased resistance
from the oil or gum,. &c., in their progress, and therefore to
modified action, the result of which is slower and slower
action, or chemical change. He also thinks it is possible
that the power of capillary attraction is balanced in the
tubes by air contained therein, after a little, sufficiently so
to prevent the acids from taking full effect. To get over
See Analysis of Explosives.
NITRATED GUN-COTTON. 83
this, Mr France uses his cotton in a fine state, almost dust,
in fact, and then nitrates in the usual mixture of acids at
40° to 90° F., the excess of acids being removed by pressure.
He says he does not find it necessary to wash this fine
cotton dust in an alkaline solution previous to nitration.
His mixed acids consist of 8 parts HNO8 = 42° B., and 12
parts H2SO4 = 66° B., and he stirs in the dipping tank for
fifteen minutes, the temperature being 50° F. to 100° F.,
the temperature preferred being 75° F.
"Nitrated" Gun-Cotton.— The nitrates that are or
have been mixed with gun-cotton in order to supply
oxygen are potassium nitrate, ammonium nitrate, and
barium nitrate (tonite). The total combustion of gun-
cotton by potassium nitrate corresponds to the equation : —
or 828 grms. of nitrate for 1,143 gnus, of gun-cotton, or
42 per cent, nitrate and 58 per cent, gun-cotton. The
explosive made at Faversham by the Cotton Powder
Company, and known as tonite No. I, consists of very
nearly half gun-cotton and half barium nitrate. The
relations by weight of total combustion would be $1.6 of
gun-cotton to 48.4 of barium nitrate. The average com-
position of tonite I have found by analysis to be 51 per
cent, gun-cotton to 49 per cent, barium nitrate. The heat
liberated is practically the same as for an equivalent weight
of KNO3 ; but the barium nitrate mixture weighs 2,223
grms. instead of 1,971 grms., or one-eighth more. The
advantage in mixing a nitrate with gun-cotton is that it
supplies oxygen, and by converting all the carbon into
carbonic acid, prevents the formation of the poisonous gas
carbonic oxide (CO). The nitrates of potassium and barium
are also used admixed with nitro-cellulose in several of the
sporting smokeless powders.
84 NITRO-EXPLOSIVES.
The Manufacture of Tonite. — The explosive tonite
was patented by Messrs Trench, Faure, and Mackie, and
is manufactured at Faversham and Melling at the works of
the Cotton Powder Company, and at San Francisco by the
Tonite Powder Company. It consists of finely divided and
macerated gun-cotton incorporated with finely ground
nitrate of barium which has been carefully recrystallised.
It is made by acting upon carbonate of barium* with nitric
acid. The wet and perfectly purified, finely pulped gun-
cotton is intimately mixed up between edge runners with
about the same weight of nitrate, and the mixing and
grinding continued until the whole has become an intimately
mixed paste. This paste is then compressed into cartridges,
formed with a recess at one end for the purpose of inserting
the detonator. The whole is then covered with paraffined
paper.
The tonite No. 2 consisted of gun-cotton, nitrates of
potash and soda, charcoal and sulphur. Tonite No. 3 f is
composed as follows : — Gun-cotton, 19 per cent. ; di-nitro-
benzol, 13 per cent. ; and barium nitrate, 68 per cent, or
similar proportions. It is a yellowish colour, and being
slower in its explosive action, is better adapted for blasting
soft rock.
Tonite is extensively used in torpedoes and for sub-
marine blasting, also for quarries, &c. Large quantities
were used in the construction of the Manchester Ship Canal.
Among its advantages are, that the English railways will
take tonite on the same footing as gunpowder ; it is a very
dense material ; if wetted it can easily be dried in the sun ;
it very readily explodes by the use of a proper detonator ;
while it burns very slowly and without the least danger ;
the cartridges being waterproofed, it can be employed in
wet bore holes, and it can be tamped with water ; and
* VVitherite, BaCO8-faHNO$«Ba(NO»)g4-CO8-f H,O,
t Tonite No. i was patented by Messrs Trench, Faure, and
Mackie, and tonite Nos. 2 and 3 by Trench alone.
DANGERS WITH GUN-COTTON. 85
finally, as it contains sufficient oxygen to oxidise the
carbon, no carbonic oxide (CO) gas is formed, i.e., its
detonation is perfect. It is a very safe explosive to use,
being little susceptible to either blows or friction.
Not long ago, a committee, composed of Prof. P.
Bedson, Drs Drummond and Hume, Mr T. Bell, one of
H.M. Inspectors of Coal Mines, and others, in considering
the problem whether the fumes produced by the combustion
of tonite were injurious to health, carried out a series of
experiments in coal mines for this purpose. The air at the
" intake " was analysed, also the air of the " return," and
the smoky air in the vicinity of the shot holes. The
cartridge was surrounded by the flame-extinguishing mix-
ture, and packed in a brown paper bag. During the first
experiment nineteen shots were fired ( = 6.29 Ibs. tonite).
The " return " air showed only a trace of carbonic oxide gas
(CO). At the second experiment thirteen shots were fired
( = 4.40 Ibs. tonite), and analysis of the air of the "return "
showed that CO was present in traces only, whilst the fumes
contained only 1.9 to 4.8 parts per 10,000.
Dangers in connection with the Manufacture of Gun-
cotton, &c. — Of all the nitro compounds, the least dangerous
to manufacture are gun-cotton and collodion-cotton. The
fact that the Stowmarket Factory is within five minutes'
walk of the town shows how safe the manufacture of this
explosive is regarded. With the exception of the nitration
and the compression into blocks or discs, the whole process
is worked with a large excess of water, and the probability
of an explosion is thus reduced to a minimum. Among
the precautions that should, however, be taken, are— first,
the careful extraction of the resinous and soluble substances
from the cotton before nitration, as it was shown many
years ago by Sir F. A. Abel that the instability of the gun-
cotton first manufactured in England and Austria was
chiefly due to these compounds. They are generally re-
moved by boiling the cotton in a soda solution.
86 NITRO-EXPLOSIVES.
The actual nitration of cotton is not a dangerous
operation, but the operations of wringing in the hydro-
extractors, and washing the nitre-cotton after it leaves the
first centrifugal machine, are somewhat so. Great care
should be taken that the wrung-out nitro-cotton at once
comes in contact with a large excess of water, *>., is at
once immersed entirely in the water, since at this stage
it is especially liable to decomposition, which, once started,
is very difficult to stop. The warmer the mixture and the
less water it contains, the more liable it is to decomposition ;
hence it is that on warm and damp days the centrifugal
machines are most likely to fire. The commencement of
decomposition may be at once detected by the evolution
of red fumes. Directly the gun-cotton is immersed in the
large quantity of water in the beater and poacher it is safe.
In order that the final product may be stable and have
good keeping qualities, it is necessary that it should be
washed completely free from acid. The treatment in the
beater and poacher, by causing the material to assume the
state of a fine pulp, in contact with a large quantity of
water, does a good deal to get rid of the free acid, but the
boiling process is absolutely necessary. It has been pro-
posed to neutralise the free acid with a dilute solution of
ammonia ; and Dr C. O. Weber has published some experi-
ments bearing upon this treatment. He found that after
treatment with ammonia, pyroxyline assumed a slightly
yellowish tinge, which was a sure sign of alkalinity. It
was then removed from the water, and roughly dried
between folds of filter paper, and afterwards dried in an
oven at 70° C. After three hours, however, an explosion
took place, which entirely destroyed the strong copper
oven in which the nitro-cotton (about one oz.) had been
drying. The explosion was in some respects remarkable.
The pyroxyline was the di-nitro-cellulose (or possibly the
penta-nitro ?), and the temperature was below the igniting
point of this material (40° C. would have been a better
temperature). Dr Weber determined the ignition point of
DANGERS WITH GUN-COTTON. 8/
his di-nitro-cellulose, and found it to be 194° to 198° C,
and he is therefore of opinion that the explosion was due
to the treatment of the partially washed material with
ammonia. A certain quantity of ammonium nitrate was
probably formed, and subsequently dried upon the nitro-
cellulose, in a state of very fine subdivision. The faintest
trace of acid would then be sufficient to bring about the
explosive ignition of the ammonium nitrate.
The drying of gun-cotton or collodion-cotton is also a
somewhat dangerous operation. A temperature of 40°
C. (104° F.) should not be exceeded, and thermometers
should be placed in the nitro-cotton, and the temperature
frequently observed. An electric alarm thermometer is
also a useful adjunct to the cotton drying house. Great
care must also be taken that there are no exposed hot-
water pipes or stoves in the drying house, as the fine gun-
cotton dust produced by the turning or moving of the
material upon the shelves would settle upon such pipes or
stoves, and becoming hot, would be very sensitive to the
least friction. The floor also should be covered with
linoleum or indiarubber. When hot currents of air are
made to pass over the surface of gun-cotton, the gun-cotton
becomes electrified. It is important, therefore, to provide
some means to carry it away. Mr W. F. Reid, F.I.C.,
was the first to use metal frames, carriers, and sieves, upon
which is secured the cloth holding the gun-cotton, and to
earth them.
The compression of gun-cotton into blocks, discs, &c.,
is also attended with considerable risk. Mr O. Guttmann,
in an interesting paper upon " The Dangers in the Manu-
facture of Explosives " (Jour. Soc. Chem. Ind., No. 3, vol.
xi., 1892), says: "The compression of gun-cotton into
cartridges requires far more care than that of gunpowder,
as this is done in a warm state, and gun-cotton even when
cold, is more sensitive than gunpowder. When coming
out of the centrifugal machines, the gun-cotton should
always pass first through a sieve, in order to detect nails
88 NITRO-EXPLOSIVES.
or matches which may by chance have got into it. What
has been said as to gunpowder presses applies still more
to those for gun-cotton, although the latter are always
hydraulic presses. Generally the pistons fit the mould per-
fectly, that is to say, they make aspiration like the piston
of a pump. But there is no metal as yet known which for
any length of time will stand the constant friction of com-
pression, and after some time the mould will be wider in
that part where the greatest compression takes place. The
best metal for this purpose has proved to be a special steel
made by Krupp, but this also is only relatively better ; for
pistons I prefer hard cast iron. If the position of the
moulds and pistons is not exactly the same in all cases,
what the Germans call ' Ecken ' (English ' binding ') will
take place, viz., the mould will stand obliquely to the
piston, and a dangerous friction will result." " Of course,
it is necessary to protect the man working the hydraulic
valves during compression. At Waltham Abbey they
have a curtain made of ship's hawsers, which is at the same
time elastic and resistant." Mr Guttmann has found that
a partition wall 12 inches thick, made of 2-inch planks, and
filled with ground cinders, gives very effective protection.
A door in this partition enables the workman to get to the
press, and a conical tube penetrates the wall, enabling the
man to see the whole work from a safe standpoint. The
roof, or one side of the building, should be of glass, so as to
give the explosion a direction.
Trench's Fire-extinguishing Compound is manu-
factured by the Cotton Powder Company at Faversham,
and is the invention of Mr George Trench, F.C.S., the
manager of the Company. The object of the invention
is to surround the cartridges of tonite, when used in coal
mines, with a fire-extinguishing compound. If a charge of
tonite, dynamite, or gelatine dynamite is put inside a few
ounces of this mixture, and then fired, not the least trace
of flame can be observed, and experiments appear to show
FIRE-EXTINGUISHING COMPOUND.
89
that there is no flame at all. The compound consists of
sawdust impregnated with a mixture of alum and chlorides
of sodium and ammonia. Fig. 22 shows the manner of
placing the tonite cartridge in the paper bag, and surround-
ing it with the fire-extinguishing compound, a a. The
attachment of the fuse and detonator is also shown.
The following report (taken from the Favershain News,
22nd Oct. 1887) of experiments conducted in the presence
of several scientific and mining men will show its value : —
" A large wrought-iron tank, of 45 cubic feet capacity, had
been sunk level with the ground in the middle of the yard ;
FIG. 22. — TRENCH'S FIRE-EXTINGUISHING CARTRIDGE.
to this tank the gas had been laid on, for a purpose that
will be explained later on. The charges were fired by
means of electricity, a small dynamo firing machine being
placed from 30 to 40 yards away from the ' mine.' " Opera-
tions were commenced by the top of the tank being covered
over and plastered down in order to make it air-tight ; then
a sufficient quantity of coal gas was placed in it to make it
highly inflammable and explosive, the quantity being ascer-
tained by a meter which had been fixed specially for the
purpose. Whilst the gas was being injected the cartridge
was prepared.
The first experiment was to try whether a small charge
of tonite — fired without the patent extinguisher — would
ignite the gas. The gas having been turned on, a miner's
lamp was placed in the " tank," but this was extinguished
before the full quantity of gas had gone through the meter.
However, the gas being in, the charge of i\ oz. tonite was
90 NITRO-EXPLOSIVES.
placed in the " mine," the detonator was connected by
means of long wires to the dynamo machine, and the word
was given to " fire." With a tremendous report, and a flash
of fire, the covering of the mine flew in all directions, clearly
showing that the gas had exploded. The next cartridge (a
similar charge) was prepared with the patent compound.
First of all a brown paper case of about 2 inches diameter
was taken, and one of the tonite cartridges was placed in
the centre of it, the intervening space between the charge
and the case being packed with the " fire-extinguishing
compound." The mine having had another supply of gas
injected, the protected cartridge was placed inside and
fired. The result was astonishing, the explosion not being
nearly so loud, whilst there was not the least flash of fire.
" Protected " and " unprotected " charges were fired at
intervals, gas being turned into the tank on each occasion.
Charges of tonite varying from I to 6 oz. were also used
with the compound. The report was trifling, whilst no
flash could be seen.
Uses of Collodion-Cotton. — The collodion or soluble
gun-cotton is used for a variety of purposes. The chief use
is, however, for the manufacture of the various explosive
gelatine compounds, of which blasting gelatine is the type.
It is also very extensively used in the manufacture of
smokeless powders, both military and sporting — in fact,
very few of them do not contain it. In some, however,
nitro-lignose or nitrated wood is used instead. This, how-
ever, is chemically the same thing, viz., nitro-cellulose, the
cellulose being derived from the wood fibre. It is more
used in this connection than the higher nitrate gun-cotton.
Another use to which it has been applied very extensively,
of recent years, is in the manufacture of " celluloid." It is
used in photography for the preparation of the films on the
sensitised plates, and many other purposes. Dissolved in
a solution of two parts ether and one of alcohol, it forms
the solution known as collodion, used for a variety of
CELLULOID. 91
purposes, such as a varnish, as a paint for signals ; in
surgery, for uniting the edges of wounds.
Quite lately, Mr Alfred Nobel, the well-known inventor
of dynamite, has patented the use of nitro-cellulose, hydro-
or oxy-cellulose, as an artificial substitute for indiarubber.
For this purpose it is dissolved in a suitable non-volatile or
slightly volatile " solvent," such as nitro-naphthalene, di-
nitro-benzene, nitro-toluene, or its homologues ; products
are obtained varying from a gelatinous consistency to the
hardness of ebonite. The proportions will vary from about
20 per cent, of nitro-cellulose in the finished product, form-
ing a soft rubber, to 50 per cent, nitrating celluloid, and the
" solvent " chosen will depend on the use to which the
rubber substitute is to be put, the liquids giving a more
elastic substance, whilst mixtures of solids and liquids may
be employed when the product is to be used at high tem-
peratures. By means of rollers steam heated, the incor-
poration may be accomplished without the aid of a volatile
liquid, or the nitro-cellulose may be employed wet, the
water being removed after " solution."
It is advisable to use the cellulose nitrated only just
enough to render it suitable, in order to reduce the
inflammability of the finished product. Mr W. Allen,
M.P., of Gateshead, proposed to use celluloid for cartridge
cases, and thus to lighten ammunition, and prevent jamb-
ing, for the case will be resolved into gases along with the
powder. Extractors will also be done away with.
Celluloid is an intimate mechanical mixture of pyr-
oxyline (gun-cotton or collodion-cotton) with camphor, first
made by Hyatt, of Newark, U.S.A., and obtained by adding
the pyroxyline to melted camphor, or by strongly com-
pressing the two substances together, or by dissolving the
constituents in an appropriate solvent, e.g., alcohol or ether,
and evaporating to dryness. A combination of the two latter
methods, i.e., partial solution, with pressure, is now usually
adapted. The pyroxyline employed is generally the tetra-
92 NITRO-EXPLOSIVES.
and penta-nitrated cellulose, the hexa-nitrate (gun-cotton)
being but seldom used on account of its explosive properties.
Care is taken to prevent the formation of the hexa-
nitrate by immersing the cellulose in only moderately
strong nitric acid, or in a warm mixture of nitric and
sulphuric acids. The paper, either in small pieces or in
sheets, is immersed for about twenty-five minutes in a
mixture of 2 parts of nitric acid and 5 parts of sulphuric
acid, at a temperature of about 30° C., after which the nitrated
cellulose is thoroughly washed with water to remove the
last traces of free acid, pressed, and whilst still moist, mixed
with the camphor.
In the process of Trebouillet and De Besancele, the
cellulose, which may be in the form of paper, cotton, or
linen, is twice nitrated — first in the acid mixture employed
in a previous operation ; and secondly, in a fresh mixture
of 3 parts sulphuric acid of 1.83 specific gravity, and 2 parts
concentrated nitric acid containing nitrous acid. After
each nitration the mass is subjected to pressure, and is then
carefully washed with water, to which, at the last, a small
quantity of ammonia or caustic soda is added to remove
the final traces of acid. The impregnation of the pyroxyline
with the camphor is effected in a variety of ways.
The usual proportion of the constituents is 2 parts
pyroxyline and I part camphor. In Trebouillet and De
Besancele's process, 100 parts of pyroxyline are intimately
mixed with from 40 to 50 parts camphor, and moulded
together by strong pressure in a hot press, and afterwards
dried by exposure to air, desiccated by calcium chloride or
sulphuric acid. The usual method is, however, to dissolve
the camphor in the least possible quantity of alcohol, and
sprinkle the solution over the dry pyroxyline, which is then
covered with a second layer of pyroxyline, and the whole
again treated with the camphor solution, the addition of
pyroxyline and camphor solution being repeated alternately
until the requisite amount of celluloid mixture is obtained.
The mass, which sinks together in transparent lumps, is
CELLULOID. 93
worked for about an hour between cold iron rollers, and
then for the same period between rollers which can be
gently heated by steam. The layer of celluloid surround-
ing the rollers is then cut away and again pressed, the
resulting cake, which is now about I cm. thick, being cut
into plates of about 70 cm. long and 30 cm. broad. These
are placed one above the other, and strongly pressed together
by hydraulic pressure at a temperature of about 70° for
twenty-four hours. The thick cakes are once more cut
into plates of the desired thickness, and placed in a chamber
heated from 30° to 40° for eight to fourteen days, whereby
they become thoroughly dry, and are readily made into
various articles either by being moulded while warm under
pressure, cut, or turned. Occasionally other liquids, e.g.,
ether and wood spirit, are used in place of alcohol as
solvents for the camphor.
Celluloid readily colours, and can be marbled for
manufacturing purposes, Sec. It is highly inflammable
and not explosive even under pressure, and may be worked
under the hammer or between rollers without risk. It
softens in boiling water, and may be moulded or pressed.
Its specific gravity varies slightly with its composition and
with the degree of pressure it has received. It is usually
1.35. It appears to be merely a mixture of its components,
since by treatment with appropriate solvents the camphor
may be readily extracted, and on heating the pyroxyline
burns away while the camphor volatilises.
The manufacture of pyroxyline for the purpose of
making celluloid has very much increased during recent
years, and with this increase of production improved
methods of manufacture have been invented. A series of
interesting papers upon the manufacture of pyroxyline
has been published by Mr Walter D. Field, of New York,
in the Journal of the American Chemical Society* from
which the following particulars are taken : —
* Vol. xv., No. 3, 1893 ; Vol. xvi., No. 7, 1894 ; Vol. xvi., No/ 8, 1894.
Figs. 19, 20, 21, 22, and 23 are taken from Mr Field's paper.
94 NITRO-EXPLOSIVES.
Selection of the Fibre.— Cotton fibre, wood fibre, and
flax fibre in the form of raw cotton, scoured cotton, paper,
and rags are most generally used, and give the best results.
As the fibres differ greatly in their structure, they require
different methods of nitrating. The cotton fibre is a
flattened hollow ribbon or collapsed cylindrical tube,
twisted a number of times, and closed at one end to form
a point. The central canal is large, and runs nearly to
the apex of the fibre. Its side walls are membraneous,
and are readily penetrated by the mixed acids, and conse-
quently the highest nitration results. In the flax fibre the
walls are comparatively thick, the central canal small ;
hence it is to be presumed that the nitration must proceed
more slowly than in the case of cotton. The New Zealand
flax gives the most perfectly soluble nitrates of any of the
flaxes. Cotton gives a glutinous collodion, and calico a
fluid collodion. One of the largest manufacturers of
pyroxyline in the States uses the " Memphis Star " brand
of cotton. This is an upland cotton, and its fibres are very
soft, moist, and elastic. Its colour is light creamy white,
and is retained after nitration. The staple is short, and the
twist inferior to other grades, the straight ribbon-like
filaments being quite numerous. This cotton is used
carded, but not scoured. This brand of cotton contains a
large quantity of half and three-quarter ripe fibre, which is
extremely thin and transparent, distributed throughout the
bulk of the cotton (Monie., Cotton Fibre, 67). Mr Field says,
" This is a significant fact when it is known that from this
cotton an extremely soluble pyroxyline can be produced."
Pyroxyline of an inferior grade as regards colour only
can be produced from the cotton wastes of the trade.
They must be scoured before they are fit for nitrating.
Paper made from the pulps of sulphite and sulphate
processes is capable of yielding a very soluble pyroxyline.
It can be nitrated at high temperatures and still yield good
results. Tissue paper made from flax fibre is also .used
after being cut into squares.
NITRATION OF FIBRE. 95
Mowbray (U.S.P., No. 443, 105, 3rd December 1890)
says that a pure cotton tissue paper less than g-J^ inch
in thickness, thin as it is, takes on a glutinous or colloid
surface, and thus requires some thirty minutes to enable
the nitration to take place. With a thicker paper only the
surface would be nitrated. He therefore uses a fibre that
has been saturated with a solution of nitrate of soda, and
afterwards dried slowly, claiming that the salt crystallises
in the fibre, or enters by the action termed osmose, and
opens up the fibre to the action of the acid. This process
would only be useful when the cotton is to be nitrated at a
low temperature. At a high temperature it would be
unnecessary.
Dietz and Wayne (U.S. P., No. 133, 969) use ramie,
rheca, or China grass for producing a soluble pyroxyline.
That made from ramie is always of uniform strength and
solubility, and requires a smaller quantity of solvent to
dissolve it than that made from cotton. Mr Field's
experience, however, is entirely contrary to this statement.
Such is the influence of the physical form of the fibre on the
process of nitration, that when flax fibre and cotton fibre
are nitrated with acid mixtures of exactly the same
strength, and at the same temperature, the solution of the
first is glutinous or thick, and the second fluid or thin.
By simply nitrating at a higher temperature than the
cotton, the flax will yield a pyroxyline giving an equally
fluid collodion.
The presence of chlorine in the fibre must be carefully
avoided, as such a fibre will yield an acid product which
cannot be washed neutral. The fibre must be dry before
nitration ; and this is best done, according to Mr Field, by
using the form of drier used in drying wool.
Nitration of the Fibre. — Mixed cotton and flax fibre
in the form of paper, from T^j-o- to WW mcn thick, and cut
into i -inch squares, is nitrated by the Celluloid Manufac-
turing Company, and the same paper, left in long strips,
96 NlTRO-EXPLOSiVES.
I inch wide, is used for nitration by the Xylonite Manu-
facturing Company, of North Adams, Mass. (U.S.A.).
The Celluloid Company introduce the cut paper into
the mixed acids by means of a hollow, rapidly revolving
tube, flared at the lower end, and immersed in the mixed
acids. The centrifugal force of the revolving tube throws
the paper towards the sides of the vessel, leaving the
centre of the vessel ready for fresh paper.
The Xylonite Company simply cut the paper into long
strips, and introduce it into the mixed acids by means of
forks. The arrangement used by this Company for holding
the mixed acids is a cylindrical vessel divided into a number
of sections, the whole revolving like a turntable, thus
allowing the workman to nitrate successively each lot of
paper at a given point. This Company did not remove
the acid from the paper after its immersion, but plunged it
immediately into the water, thus losing a large proportion
of the waste acid. The Celluloid Company, by using the
paper in smaller pieces, and more paper to a pound of acid,
and wringing the mixed acid from the paper before immer-
sion in water, had a better process of nitration.
Other manufacturers use earthenware vessels, and glass
or steel rods, hooked at one end, having small pieces of
rubber hose pulled over the
other end to prevent the hand
from slipping. The form of
vessel in general use is that
given in Fig. 23. It is large
FIG. 23.— VESSEL FOR NITRATING
COTTON OR PAPER. CllOUgh to nitrate I lb. of
cotton at a time. The hook at one end of the rod enables
the workman to pull the pyroxyline apart, and thus en-
sures saturation of the fibre. In the winter the room in
which the nitrating is done must be kept at a temperature
of about 70° F. in order to secure equality in the batches.
The nitrating apparatus of White and Schupphaus
(U.S.P., No. 418, 237, 89) Mr Field considers to be, both
novel and excellent. The cage (Fig. 24), with its central
CELLULOID — APPARATUS USED. 0?
perforated cylinder (Fig. 25), is intended to ensure the
rapid and perfect saturation of the tissue paper used for
nitrating. The patentees say that no stirring is required
with their apparatus. This, says Mr Field, might be true
when paper is used, or even cotton, when the temperature
FIG. 24.— CENTRAL PERFORATED FIG. 25. — THE CAGE.
CYLINDER.
WHITE AND SCHUPPHAUS' NITRATING APPARATUS.
of nitration is from 30° to 35° C, but would not be true if
the temperature were raised to 50° to 55° C. The process
is as follows : — The paper is nitrated in the cage (Fig. 25),
the bottom of which is formed by the flanged plate C, fastened
FIG. 26. — CELLULOID NITRATING POT.
FIG. 27. — ANOTHER VIEW.
to the bottom of the internal cylinder B. After nitration
the cage is carried to a wringer, which forms the basket,
and the acids removed. Finally, the cage is taken to a
plunge tank, where the paper is removed from the cage by
simply pulling out the central perforated cylinder B. Fig.
G
98 fclTRO-EXPLOSlVES.
26 shows the nitrating pot, with its automatic cover. The
plunge tank is shown in plan and section in Figs. 28 and 29.
This apparatus is suitable for the nitration of cotton fibre
in bulk at high or low temperatures. Other methods that
FIGS. 28, 29. — PLUNGE TANK, IN PLAN AND SECTION.
have been patented are Mowbray's (U.S.?., No. 434, 287),
in which it is proposed to nitrate paper in continuous
lengths, and Hyatt's (U.S.P., No. 210, 611).
The Acid Mixture. — Various formulae have been pub-
lished for producing soluble nitro-cellulose. In many
instances, although the observations were correct for the
single experiment, a dozen experiments would have pro-
duced a dozen different products. The composition of
the acids used depends upon the substance to be nitrated,
and the temperature at which the nitration will be worked.
Practically there are three formulae in general use — the one
used by the celluloid manufacturers ; another in which the
cotton is nitrated at high temperatures ; and a third in
which the temperature of the immersion is low, and the
time of nitration about six hours. Of the three, the best
method is the last one, or the one in which the cotton is
immersed at a low temperature, and then the reaction
allowed to proceed in pots holding from 5 to 10 Ibs.
of cotton. The formula used by the celluloid manu-
facturers for the production of the low form of nitrated
product which they use is : —
ACID MIXTURE. 99
Sulphuric acid 66 parts by weight.
Nitric acid - - 17 „ „
Water 17
Temperature of immersion, 30° C. Time, twenty to
thirty minutes.
The cellulose is used in the form of tissue paper TIRJTT
inch thick, I Ib. to 100 of acid mixture. The nitro-
cellulose produced by this formula is very insoluble in the
compound ethers and other solvents of pyroxyline, and is
seemingly only converted or gelatinised by the action of
the solvent. The next formula produces a mixture of
tetra- and penta-nitro-celluloses hardly soluble in methyl-
alcohol (free from acetone), but very soluble in anhydrous
compound ethers, ketones, and aldehydes : —
Nitric acid, sp. gr. 1.435 - - 8 Ibs.
Sulphuric acid, sp. gr. 1.83 - - 15! „
Cotton - 14 oz.
Temperature of nitration, 60° C. Time of immersion,
forty-five minutes.
The 60° of temperature is developed by mixing the acids
together. The cotton is allowed to remain in the acid
until it feels " short " to the rod.
The following table, due to Mr W. D. Field, shows
very plainly the great variation in the time of the immer-
sion and the temperature by seemingly very slight causes.
It extends over fourteen working days, during which time
it rained four days. The formula used is that given above,
except that the specific gravity of the nitric acid is some-
what lower. The product obtained differs only from that
produced by using nitric acid of specific gravity 1.43
in being soluble in methyl-alcohol. From 30 to 35 Ibs.
of pyroxyline were produced in each of the fourteen days.
A careful examination of this table will prove* very
instructive. The increase in yield varies from 31 per cent,
to nothing, and the loss runs as high as 10 per cent, yet
care was taken to make the product uniform in quality.
On the days it rained there was a loss, with the exception
100
NITRO-EXPLOSIVES.
of the fourth day, when there was neither a loss nor a gain.
On the days it was partly clear, as just before or after rain,
the table shows a loss in product. We can explain this
fact by reason of the moisture-absorbing qualities of the
cotton. On the rainy days it would absorb the moisture
from the air until, when immersed in the acids, they were
weakened, and the fibre dissolved more or less in weakened
acid, producing what is known as " burning " in the batch.
Specific Gravity.
Time. Jemp^ Percentage
H2S04.
HNO3.
i
1
ai
g
. 1
i : E
C o
; g
• 8
r~ U
i
S3
3
X
8 ** 1 S 1 i3
3
.
i Clear
8^8
A2AQ
20
£-7°
62° 71
2 ....
8^7
A.2AQ
20
2
3/
• 60°
62° ' 18
• • *
3. Cloudy
•837
.4226
45
2
... 60°
62° 7
...
4. Rain
.837
.420
20
I
2O j 60°
67° ! O
o
5 Clear
8^.77
d.2
I c
2
<;80
62° i c
6. Rainy
7. Cloudy
.8391
.835
.422
.4226
-•
35
20
40 i 5«°
TC 62°
62° i ...
64.°
2 I
IO
8 Clear
ST;
422
-sc
10 60°
62° c
9. Partly clear
•"JD
.824
.4271
20
!
... 50°
* o •>
60 ...
3
10. ,,
.83
.4271 ..
IO
25 580
60° ...
IO
ii. Cloudy
.872 42S
IO
50 58° 60° 8
12. Rainy .
1.822 .42?
IO
20 58° | 60°
IO
13. Partly clear
1.8378 .4257 1 ..
50
I
40 50° 58° 20
14. Cloudy
1.837 i .4257 ( I
56 i 4
40 50° ! 60° 1 6
...
It will also be noticed that on days which show a loss, the
time of the immersion was correspondingly short, as on the
tenth, twelfth, and seventh days.
The lesson this table teaches is, that it is almost im-
possible to nitrate cellulose in small quantities, and get
uniform results, when the nitration is carried on at high
temperatures. As regards the solubility of pyroxyline,
Parks found that nitro-benzene, aniline, glacial acetic acid,
and camphor, dissolved in the more volatile solvents
methyl-alcohol and alcoho.-etner, were much the .best
solvents for producing a plastic, as they are less volatile,
ACID MIXTURE. IOI
and develop greater solvent action under the influence of
heat. Nitro-benzene gives a solution that is granular ; it
seems to merely convert the pyroxyline, and not to dissolve
it ; but on the addition of alcohol, a solution is at once
obtained, and the granular appearance disappears, and the
solution becomes homogeneous. The acid mixture and
the method of nitrating have much to do with the action
of the various solvents, so also has the presence of water.
Dr Schupphaus found that propyl and isobutyl alcohols
with camphor were active solvents, and the ketones, palmi-
tone, and stearone in alcohol solution, also alpha- and beta-
naphthol, with alcohol and anthraquinone (diphenylene
diketone) in alcoholic solution, and also iso- valeric aldehyde
and its derivatives, amyliden-dimethyl and amyliden-diethyl
ethers.
August Sayer (U.S.P., No. 470, 45 i) finds diethyl-ketone,
dibutyl-ketone, di-pentyl-ketone, and the mixed ketones,*
methyl-ethyl, methyl-propyl, methyl-butyl, methyl-amyl,
and ethyl-butyl ketones are active solvents of pyroxyline ;
and Paget finds that although methyl-amyl oxide is a
solvent, that ethyl-amyl oxide is not.
The solvents of pyroxyline can be divided into general
classes — First, those which are solvents without the aid of
heat or solution in alcohol ; second, those that are solvents
when dissolved in alcohol. These solvents are those which
also develop a solvent action when heated to their melting
point in combination with pyroxyline.
Mr W. D. Field groups the solvents of pyroxyline into
classes thus : Two of the monohydric alcohols ; compound
* Ketones are derived from the fatty acids by the substitution of
tire hydroxyl of the latter by a monad positive radical. They thus re-
semble aldehydes in constitution. The best-known ketone is acetone
CH3.CO.CHo. Mixed ketones are obtained by distilling together
salts of two different fatty acids. Thus potassic butyrate and potassic
acetate form propyl-methyl-ketone —
|C(C,H5)H,1
\CO.CH3 I
102 NITRO-EXPLOSIVES.
ethers of the fatty acids with monohydric alcohols, alde-
hydes ; simple and mixed ketones of the fatty acid series.
These four classes include the greater number of the
solvents of pyroxyline. Those not included are as follows :
— Amyl-nitrate and nitrite, methylene-di-methyl ether,
ethidene-diethyl ether, amyl-chloracetate, nitro-benzeneand
di-nitro-benzene, coumarin, camphor, glacial acetic acid,
and mono-, di-, and tri-acetin.
Richard Hale uses the following solvent : — Amyl-
acetate, 4 volumes ; petroleum naphtha, 4 volumes ; methyl -
alcohol, 2 volumes ; pyroxyline, 4 to 5 ounces to the gallon
of solvent. Hale used petroleum naphtha to hasten the
drying qualities of the varnish, so that it would set on the
article to be varnished before it had a chance to run off.
It is, however, the non-hygroscopic character of the solvent
that makes the varnish successful. This formula is very
largely used for the production of pyroxyline varnish, which
is used for varnishing pens, pencils, &c., also brass-work
and silver-ware.
The body known as oxy-cellulose* is formed by the
action of nitric acid upon cellulose when boiled with it.
The quantity formed is about 30 per cent, of cellulose acted
upon. When washed free from acid, it gelatinises. It is
then soluble in dilute alkalies, and can be reprecipitated
from solution by alcohol, acids, or saline solutions. Messrs
Cross and Bevan assign to it the formula C18H26O16. It
dissolves in concentrated sulphuric acid, and with nitric
acid forms a nitro body of the formula C18H23O1G3(NO2),
which is prepared as follows : — The gelatinous oxy-cellulose
is washed with strong nitric acid until free from water, and is
then diffused through a mixture of equal volumes of strong
sulphuric and nitric acids, in which it quickly dissolves.
The solution, after standing for about an hour, is poured
in a fine stream into a large volume of water, by which the
* " On the Oxidation of Cellulose," by C. F. Cross and E. J. Bevan,
Jour. Chem. Soc., 1883, p. 22.
NITRO-STARCH. 103
unitro" body is precipitated as a white flocculent mass.
The product, after drying at 110° C, was found upon
analysis to contain 6.48 per cent nitrogen.
MISCELLANEOUS NITRO-EXPLOSIVES.
Nitro-Starch. — It is only recently that, by means of
the process introduced by the " Actiengesellschaft Dyna-
mit Nobel," it has been possible to make this explosive
upon the manufacturing scale. Nitro-starch has been
known since 1883, when Braconnot discovered it, and
called it xyloidine. Its formula is C6H8O3(NO3)2, but Dr
Otto Miihlhausen has lately succeeded in preparing higher
nitrated compounds, viz. : —
(a.) C6H7t02i(N03)2i.
(/>.) C6H704(N03)3.
Or doubling the molecule of starch : —
Nitrogen.
i. Tetra-nitro-starch C12H16Ofi(ONO.,)1 - - - u. u per cent,
ii. Penta-nitro-starch QoH^OrXONCy-, - - - 12.75 »
iii. Hexa-nitro-starch C12H14O4(ONOo)fi - - - - 14.14 ,,
He regards them as true ethers (esters) of nitric acid.
Thus on treatment with sulphuric acid, these compounds
yield NO3H, the residue O.NO2 thus appearing to be re-
placed by the sulphuric acid residue. On treatment with
a solution of ferrous chloride, nitric oxide and "soluble"
starch are regenerated. On shaking with sulphuric acid
over mercury, all the nitrogen is split off as NO.
Tetra-nitro-starch is prepared upon the large scale as
follows : — A quantity of potato-starch is taken and exposed
in some suitable desiccating apparatus at a temperature of
100° C. until all the moisture which it contains is com-
pletely driven off. It is then reduced to a fine powder by
grinding, and dissolved in nitric acid of specific gravity
1.501. The vessel in which this solution is accomplished
is made of lead, and must be provided with two jackets,
cooled by means of water. It should further be fitted with
104 NITRO-EXPLOSIVES.
a screw-agitator, in order to keep the nitric acid circulat-
ing freely. The charge of starch is introduced through an
opening in the cover of this digesting vessel, and the pro-
portions of acid to starch are 10 kilogrammes of starch to
100 kilos, of acid. The temperature is kept within the
limits 20° to 25° C. When the solution of the starch is
complete, the liquid is conducted into a precipitating ap-
paratus, which is also provided with a cooling jacket, for
the purpose of regulating the temperature. The bottom of
this vessel is double and perforated, and here is placed a
layer of gun-cotton to act as a filter. This vessel is filled
with spent nitro-sulphuric acid obtained as a waste product
from the nitro-glycerine manufactory, and the solution of
starch in nitric acid is sprayed into it through an injector
worked by compressed air, whereby the nitro-starch is
thrown down in the form of a fine-grained powdery
precipitate.
In order to precipitate 100 kilos, of the acid solution of
starch, it is necessary to employ 500 kilos, of spent nitro-
sulphuric acid. As it is precipitated the nitro-starch
collects on the gun-cotton filter, and the acid liquor is run
off through a tap placed beneath the perforated double
bottom of the vessel, and of course below the filter pad.
The precipitated starch is further cleansed from acid by
repeated washings and by pressure, until all trace of acidity
has been eliminated, and the substance exhibits a neutral
reaction. The next step is to treat the nitro-starch with a
5 per cent, solution of soda, in contact with which it is
allowed to stand for at least twenty-four hours. The pro-
duct is then ground up until a sort of " milk " or emulsion
is obtained, and lastly treated with a solution of aniline, so
that when pressed into cake, it contains about 33 per cent,
of water, and I per cent, of aniline.
Dr Miihlhausen, working on these lines in the laboratory,
prepared nitro-starch which contained 10.96 and 11.09 per
cent, of nitrogen. When in the state of powder it is snow-
white in colour ; it becomes electrified when rubbed ; it is
NITRO-STARCH. IO5
very stable, and soluble even in the cold in nitro-glycerine.
He has also prepared a tetra-nitro-starch containing 10.58
and 10.50 per cent, of nitrogen, by pouring water into a
solution of starch in nitric acid which had stood for several
days. The substance thus produced in the laboratory had
all the properties of that prepared by the other process.
The production of penta-nitro-starch is effected by
adding 20 grms. of rice-starch — previously dried at a tem-
perature of 100° C, in order to eliminate all moisture — to a
mixture of 100 grms. of nitric acid, specific gravity 1.501,
and 300 grms. of sulphuric acid, specific gravity 1.8 (some
tetra-nitro-starch is also formed at the same time). After
standing in contact with these mixed acids for one hour
the starch has undergone a change, and the mass may now
be discharged into a large quantity of water, and then
washed, first with water, and finally with an aqueous solu-
tion of soda. The yield in Dr Miihlhausen's experiments
was 147.5 Per cent.
The substance thus formed is now heated with ether-
alcohol, the ether is distilled off, and the penta-nitro-starch
appears as a precipitate, whilst the tetra-nitro-starch, which
is formed simultaneously, remains in solution in the alcohol.
As obtained by this process, it contained 12.76 and 12.98
per cent, nitrogen, whilst the soluble tetra-nitro-starch
contained 10.45 Per cent.
Hexa-nitro-starch is the product chiefly formed when
40 grms. of dry starch are treated with 400 grms. of nitric
acid, specific gravity 1.501, and allowed to stand in contact
for twenty-four hours ; 200 grms. of this mixture are then
poured into 600 c.c. of sulphuric acid of 66° B. The result
of this manipulation is a white precipitate, which contains
13.52-13.23 and 1322 per cent, nitrogen; and consists,
therefore, of a mixture of penta- and hexa-nitro-starch.
The experiments undertaken with these substances
demonstrated that those prepared by precipitating the
nitro-starch with strong sulphuric acid were less stable in
character or properties than those which were precipitated
io6
NITRO-EXPLOSIVES.
by water or weak sulphuric acid. Dr Miihlhausen is of
opinion that possibly in the former case a sulpho-group
may be formed, which in small quantity may occasion this
instability.
The following table shows the behaviour of these
substances prepared in different ways and under various
conditions : —
SAMPLES.
A.
B.
C.
D.
E.
Ignition-point -
175° C.
170° C.
152° C.
121° C.
155° C.
Stability
Stable
Stable
Unstable
Unstable
Unstable
Per cent, of N. -
11.02
10.54
12.87
12.59
13-52
96 per cent, al-
cohol
Sol.
Sol.
Insol.
Insol.
Insol.
Ether
Insol.
Insol.
Insol.
Insol.
Insol.
Ether-alcohol -
Sol.
Sol.
Sol.
Sol.
Sol.
Acetic Ether
Sol.
Sol.
Sol.
Sol.
Sol.
These samples were prepared as follows : —
A. From I part nitric acid and 2 parts sulphuric acid
(containing 70 per cent. H2O).
B. From I part nitric acid and water.
C. From I part nitric and 3 parts H2SO4 (con.).
D. From I part nitric and 3.5 parts con. H2SO4.
E. From I part nitric and 3 parts con. H2SO4.
Dr Miihlhausen is of opinion that these compounds
may be turned to practical account in the production of
good smokeless powder. He recommends the following
proportions and method. Six grms. of nitro-jute and
2 grms. of nitro-starch are mixed together, and moistened
with acetic ether. These ingredients are then worked
together into a uniform mass, and dried at a temperature
ranging between the limits 50° to 60° C. He has himself
prepared such a smokeless powder, which proved to contain
11.54 per cent, of nitrogen, and was very stable. Further
details of Dr Miihlhausen's work upon nitro-starch can be
found in Dingier s Polytechnisches Journal, paper ".Die
hohren Salpetersaureather der Starke," 1892, Band 284,
NITRO-JUTE. TO/
s. 137-143, and a Bibliography up to 1892 in Arms and
Explosives, December 1892.
M. Berthelot gives the heat of formation of nitro-starch
as 812 cals. for I grm., and the heat of total combustion as
equal to 706.5 cals. for 207 grms., or for I grm. 3,413 cals.
The heat of decomposition could only be calculated if the
products of decomposition were given, but they have not
as yet been studied, and the quantity of oxygen contained
in the compound is far from being sufficient for its com-
plete combustion. Berthelot and Vieille found the average
velocities for nitro-starch powder, density of charge about
1.2, in a tin tube 4 mm. external diameter, to be, in two
experiments, 5,222 m. and 5,674 m. In a tin tube 5.5 mm.
external diameter, the velocity was 5,816 m., and in lead
tube 5,006 m. (density i.i to 1.2). The starch powder is
hygroscopic, and is insoluble in water and alcohol. When
dry it is very explosive, and takes fire at about 350° F.
Mr Alfred Nobel has taken out a patent (Eng. Pat. No.
6,560, 88) for the use of nitro-starch. His invention relates
to the treatment of nitro-starch and nitro-dextrine, for the
purpose of producing an explosive powder, to be used in
place of gunpowder. Fie incorporates these materials with
nitro-cellulose, and dissolves the whole in acetone, which is
afterwards distilled off. A perfect incorporation of the
ingredients is thus brought about.
Nitro-Jute. — It is obtained by treating jute with nitric
acid. Its properties have been studied by Messrs Cross
and Bevan (Jour. Ckem. Soc., 1889, 199), and by Miihlhausen.
The latter used for its nitration an acid mixture composed
of equal parts of nitric and sulphuric acids, which was
allowed to act upon the jute for some time. He found
that with long exposure, z>., from three to four hours in
the acids, there was a disintegrating of the fibre-bundles,
and the nitration was attended by secondary decomposition
and conversion into products soluble in the acid mixture.
Cross and Sevan's work upon this subject leads them to
108 NITRO-EXPLOSIVES.
conclude that the highest yield of nitrate is represented by
an increase of weight of 51 per cent. They give jute the
empirical formula C12H18O9 (C==47 per cent, H = 6 per
cent., and O = 4/ per cent.), and believe its conversion into
a nitro compound to take place thus : —
C1,H1S0 + 3HN03=C12H1S06(N03)3+3H:,0.
This is equivalent to a gain in weight of 44 per cent, for
the tri-nitrate, and of 58 per cent, for the tetra-nitrate.
The formation of the tetra-nitrate appears to be the limit
of nitration of jute-fibre. In other words, if we represent
the ligno-cellulose molecule by a C19 formula, it will con-
tain four hydroxyl (OH) groups, or two less than cellulose
similarly represented. The following are their nitration
results : —
Acids used. — I. HNQ., sp. gr. 1.43, and H.2SO4=i.84 equal parts.
II. i vol.'(HNOoi.5), i vol. H2SO4(i.84).
III. i vol. HNO3(i.5), 75 vols. H2SO4(i.84).
I. = 144.4; H- = i53.3; III. = 154.4 grms. ; 100 grms. of fibre being
used in all three cases.
Duration of exposure, thirty minutes at 18° C.
The nitrogen was determined in the products, and
equalled 10.5 per cent. Theory for C12Hir>O6(NO3)3 = 9.5
per cent, and for C12H15O6(NO3)4= 1 1.5 per cent. These
nitrates resemble those of cellulose, and are in all essential
points nitrates of ligno-cellulose.
Muhlhausen obtained a much lower yield, and probably,
as pointed out by Cross and Bevan, a secondary decom-
position took place, and his products, therefore, probably
approximate to the derivatives of cellulose rather than to
those of ligno-cellulose, the more oxidisable, non-cellulose,
or lignone constituents having been decomposed. In fact,
he regards his product as cellulose penta-nitrate (C12H15O5
(ONO.?)5). The Chemiker Zeitung, xxi., p. 163, contains a
further paper by Muhlhausen on the explosive nitre-jute.
After purifying the jute-fibre by boiling it with a i per
cent, solution of sodium carbonate, and washing with water,
NITRO-MANNITE. IO9
he treated I part of the purified jute with 15 parts of nitro-
sulphuric acid, and obtained the following results with
different proportions of nitric to sulphuric acids : —
Experiment I.— i. HNO3 I. H2SO4 129.5 T7o° C. 11.96%
II. „ 2. „ 132.2 167° C. 12.15%
III. „ 3- „ 135-8 169° C. 11.91%
An experiment made with fine carded jute and the
same mixture of acids as in No. II. gave 145.4 per cent.
nitro-jute, which ignited at 192° C., and contained 12 per
cent, nitrogen. This explosive is not at present manu-
factured upon the large scale, and Messrs Cross and Bevan
are of opinion that there is no very obvious advantage in
the use of lignified textile fibre as raw materials for explosive
nitrates, seeing that a large number of raw materials con-
taining cellulose (chiefly as cotton) can be obtained at a
cheaper rate, and yield also 150 to 170 per cent, of
explosive material when nitrated, and are in many ways
superior to the products obtained hitherto from jute.
Nitro-mannite is formed by the action of nitric acid on
mannite, a hex-acid alcohol closely related to sugar. It
occurs abundantly in manna, which is the partly dried sap
of the manna-ash (Fraxinus ornus}. It is formed in the
lactic acid fermentation of sugar, and by the action of
nascent hydrogen on glucose and cellulose, or on invert
sugar. Its formula is C6H8(OH)6 and that of nitro-mannite
C6H8(NO3)6. Mannite crystallises in needles or rhombic
prisms, which are soluble in water and alcohol, and have a
sweet taste. Nitro-mannite forms white needle-shaped
crystals, insoluble in water, but soluble in ether or alcohol.
When rapidly heated, they ignite at about 374° F., and
explode at about 590° F. It is more susceptible to friction
and percussion than nitre-glycerine, and unless pure it is
liable to spontaneous decomposition. It is considered as
the nitric ether of the hexatomic alcohol mannite. It is
IIO NITRO-EXPLOSIVES.
formed by the action of a mixture of nitric and sulphuric
acids upon mannite —
C.H,(OH),+6HNO,-C.H/N01,),+6H20.
Its products of explosion are as shown in the following
equation : —
Its percentage composition is as follows : — Carbon, 15.9 per
cent; hydrogen, 1.8 per cent; nitrogen, 18.6 per cent;
and oxygen, 63.7 per cent. Its melting point is 1 12 to 113°
C., and it solidifies at 93°. When carefully prepared and
purified by recrystallisation from alcohol, and kept pro-
tected from sunlight, it can be kept for several years without
alteration.
Nitro-mannite is more dangerous than nitro-glycerine,
as it is more sensitive to shock. It is intermediate in its
shattering properties between nitro-glycerine and fulminate
of mercury. It explodes by the shock of copper on iron or
copper, and even of porcelain on porcelain, provided the,
latter shock be violent Its heat of formation from its
elements is +156.1 calories. It is not manufactured upon
the commercial scale.
Besides the nitro compounds already described, there
are many others, but they are of little importance, and are
none of them made upon the large scale. Among such
substances are nitro-coal^ which is made by the action of
nitric acid on coal ; nitro-colle, a product which results from
the action of nitric acid on isinglass or gelatine, soaked in
water. It is then treated with the usual acids.
Another method is to place strong glue in cold water
until it has absorbed the maximum amount of the latter.
The mixture is solidified by the addition of nitric acid,
nitrated in the usual way, and well washed. Abel's Gly-
oxiline is only nitrated gun-cotton impregnated with nitro-
glycerine. Nitro-lignine is only nitro-cellulose made from
wood instead of cotton ; and nitro-straw is also only nitro-
NITRO-MOLASSES, ETC. Ill
cellulose. The explosive known as KeiL's Explosive con-
tains nitro-glucose. Nitro-molasses, which is a liquid
product, has also been proposed, and nitro-saccharose, the
product obtained by the nitration of sugar. It is a white,
sandy, explosive substance, soluble in alcohol and ether.
When made from cane sugar, it does not crystallise ; but
if made from milk sugar, it does. It has been used in
percussion caps, being stronger and quicker than nitro-
glycerine. It is, however, very sensitive and very hygro-
scopic, and very prone to decomposition. Nitro-tar, made
from crude tar-oil, by nitration with nitric acid of a specific
gravity of 1.53 to 1.54. Nitro-toluol is used, mixed with
nitre-glycerine. This list, however, does not exhaust the
various substances that have been nitrated and proposed as
explosives. Even such unlikely substances as horse dung
have been experimented with. None of them are very
much used, and very few of them are made upon the manu-
facturing scale.
CHAPTER IV.
DYNAMITE AND GELATINES.
Kieselguhr Dynamite — Classification of Dynamites — Properties and Efficiency
of Ordinary Dynamite — Other Forms of Dynamite — Gelatine and Gelatine
Dynamites, Suitable Gun-Cotton for, and Treatment of — Other Materials
used — Composition of Gelignite — Blasting Gelatine — Gelatine Dynamite
— Absorbing Materials — Wood Pulp — Potassium Nitrate, &c. — Manu-
facture and Apparatus used, and Properties of Gelatine Dynamites —
Cordite — Composition and Manufacture.
Dynamite. — Dynamite consists of nitro-glycerine either
absorbed by some porous material, or mixed with some
other substance or substances which are either explosives
or merely inert materials. Among the porous substances
used is kieselguhr, a silicious earth which consists chiefly
of the skeletons of various species of diatoms. This earth
occurs in beds chiefly in Hanover, Sweden, and Scotland.
The best quality for the purpose of manufacturing dynamite
is that which contains the largest quantity of the long
tubular bacillarice, and less of the round and lancet-shaped
forms, such as pleurosigmata and dictyochea, as the tube-
shaped diatoms absorb the nitro-glycerine better, and it
becomes packed into the centre of the silicious skeleton of
the diatoms, the skeleton acting as a kind of tamping, and
increasing the intensity of the explosion.
Dynamites are classified by the late Colonel Cundill,
R.A., in his " Dictionary of Explosives " as follows :—
1. Dynamites with an inert base, acting merely as an
absorbent.
2. Dynamites with an active base, /'.£., an explosive base.
KIESELGUHR DYNAMITE. 113
No. 2 may be again divided into three minor classes, which
contain as base —
(a.) Charcoal.
(&) Gunpowder or other nitrate, or chlorate mixture.
(c.} Gun-cotton or other nitro compound (nitro-benzol,
&c.).
The first of these, viz., charcoal, was one of the first
absorbents for nitro-glycerine ever used ; the second is
represented by the well-known Atlas powder ; and the last
includes the well-known and largely used gelatine com-
pounds, viz., gelignite and gelatine dynamite, and also tonite
No. 3, &c.
In the year 1867 Nobel produced dynamite by absorbing
the nitro-glycerine in an inert substance, forming a plastic
mass. In his patent he says : " This invention relates to
the use of nitro-glycerine in an altered condition, which
renders it far more practical and safe for use. The altered
condition of the nitro-glycerine is effected by causing it to
be absorbed in porous unexplosive substances, such as
charcoal, silica, paper, -or similar materials, whereby it is
converted into a powder, which I call dynamite, or Nobel's
safety powder. By the absorption of the nitro-glycerine in
some porous substance it acquires the property of being in
a high degree insensible to shocks, and it can also be burned
over a fire without exploding."
Ordinary dynamite consists of a mixture of 75 per cent,
of nitro-glycerine and 25 per cent, of kieselguhr. The guhr
as imported (Messrs A. Haake & Co. are the chief importers)
contains from 20 to 30 per cent, of water and organic matter.
The water may be very easily estimated by drying a weighed
quantity in a platinum crucible at 100° C. for some time
and re-weighing, and the organic matter by igniting the
residue strongly over a Bunsen burner. Before the guhr
can be used for making dynamite it must be calcined, in
order not only to get rid of moisture, but also the organic
matter.
A good guhr should absorb four times its weight of
H
1 14 NITRO-EXPLOSIVES.
nitro-glycerine, and should then form a comparatively dry
mixture. It should be pale pink, red brown, or white.
The pink is generally preferred, and it should be as free as
possible from grit of all kinds, quartz particles, &c., and
should have a smooth feeling when rubbed between the
finger and thumb, and should show a large quantity of
diatoms when viewed under the microscope. The following
was the analysis of a dried sample of kieselguhr : — Silica,
94.30; magnesia, 2.10; oxide of iron and alumina, 1.3;
organic matter, 0.40; moisture, 1.90 per cent.
The guhr is generally dried in a reverberatory muffle
furnace. It is spread out on the bottom to the thickness
of 3 or 4 inches, and should every now and then be turned
over and raked about with an iron rabble or hoe. The
temperature should be sufficiently high to make the guhr
red hot, or the organic matter will not be burnt off. The
time occupied in calcining will depend of course upon the
quality of the guhr being operated upon. Those containing
a high percentage of water and organic matter will of course
take longer than those that do not. A sample of the
calcined guhr should not contain more than 0.5 per cent,
of moisture and organic matter together.
After the guhr is dry it requires to be sifted and crushed.
The crushing is done by passing it between iron rollers
fixed at the bottom of a cone or hopper, and revolving at a
moderate speed. Beneath the rollers a fine sieve should be
placed, through which the guhr must be made to pass.
The kieselguhr having been dried, crushed, and sifted,
should be packed away in bags, and care should be taken
that it does not again absorb moisture, as if it contains
anything above about five-tenths per cent, of water it will
cause the dynamite made with it to exude. The guhr thus
prepared is taken up to the danger area, and mixed with
nitro-glycerine. The nitro-glycerine used should be quite
free from water, and clear, and should have been standing
for a day or two in the precipitating house. The guhr'and
nitro-glycerine are mixed in lead tanks (about ii foot deep,
MANUFACTURING DYNAMITE. 115
and 2 to 3 feet long), in the proportions of 75 of the nitro-
glycerine to 25 of the guhr, unless the guhr is found to be
too absorbent, which will cause the dynamite to be too dry
and to crumble. In this case a small quantity of barium
sulphate, say about I per cent, should be added to the
guhr. This will lessen its absorbing powers, or a highly
absorptive sample of guhr may be mixed with one of less
absorptive power, in the proportions found by experiment
to be the best suited to make a fairly moist dynamite, but
one that will not exude.
The mixing itself is generally performed in a separate
house. In a series of lead-lined tanks the guhr is weighed,
placed in a tank, and the nitro-glycerine poured on to it.
The nitro-glycerine may be weighed out in indiarubber
buckets. The whole is then mixed by hand, and well
rubbed between the hands, and afterwards passed through
a sieve. At this stage the dynamite should be dry and
powdery, and of a uniform colour.
It is now ready to be made up into cartridges, and
should be taken over to the cartridge huts. These are
small buildings surrounded with mounds, and contain a
single cartridge machine. Each hut requires three girls —
one to work the press, and two to wrap up the cartridges.
The cartridge press consists of a short cylinder of the
diameter of the cartridge that it is intended to make. Into
this cylinder a piston, pointed with ivory or lignum vitae
wood, works up and down from a spring worked by a lever.
Round the upper edge of the cylinder is fastened a canvas
bag, into which the powdery dynamite is placed by means
of a wooden scoop, and the descending piston forces the
dynamite down the cylinder and out of the open end, where
the compressed dynamite can be broken off at convenient
lengths. The whole machine should be made of gun-metal,
and should be upright against the wall of the building.
The two girls, who sit at tables placed on each side of the
press, wrap the cartridges in parchment paper. From these
huts the cartridges are collected by boys every ten minutes
Il6 NITRO-EXPLOSIVES.
or a quarter of an hour, and taken to the packing room,
where they are packed in 5-lb. cardboard boxes, which are
then further packed in deal boxes lined with indiarubber,
and fastened down air tight. The wooden lids are then
nailed down with brass or zinc nails, and a label pasted on
the outside giving the weight and description of the contents.
The boxes should, then be removed to the magazines. It
is well to take a certain number of cartridges from the
packing house at different times during the day, say three
or four samples, and to test them by the heat test. A
sample cut from a cartridge, about I inch long, should be
placed under a glass shade, together with water (a large
desiccator, in fact), and left for some days. A good dynamite
should not, under these conditions, show any signs of
exudation, even after weeks.*
Properties of Kieselguhr Dynamite. — One cubic foot
of dynamite weighs 76 Ibs. 4 oz. The specific gravity
of 75 per cent, dynamite is, however, 1.50. It is a red or
grey colour, and rather greasy to the touch. It is much
less sensitive to shock than nitro-glycerine, but explodes
occasionally with the shock of a rifle bullet, or when struck.
The addition of a few per cent, of camphor will considerably
diminish its explosive qualities to such an extent that
it can be made non-explosive except to a very strong
fulminate detonator. The direct contact of water dis-
integrates dynamite, separating the nitro-glycerine, hence
great caution is necessary in using it in wet places. It
freezes at about 40° Fahr. (4° C.), and remains frozen at
temperatures considerably exceeding that point. When
frozen, it is comparatively useless as an explosive agent,
and must be thawed with care. This is best done by
placing the cartridges in a warming pan, which consists of
a tin can, with double sides and bottom, into which hot
* For analysis of dynamite, see chapter on " Analysis," and author's
article .in Chem. News, 23rd September 1892.
PROPERTIES OF DYNAMITE. 117
water (130° Fahr.) can be poured. The dynamite will
require to be left in for some considerable time before it
becomes soft. On no account must it be placed on a hot
stove or near a fire, as many serious accidents have occurred
in this way.
Frozen dynamite is a hard mass, with altered properties,
and requires 1.5 grm. of fulminate instead of 0.5 grm. to
explode it. Thawing may also cause exudation of the
nitro-glycerine, which is much more sensitive to shock, and
if accidentally struck with an iron tool, may explode. It
is a dangerous thing to cut a frozen cartridge with a knife.
Ramming is even more dangerous ; in fact it is not only
dangerous, but wasteful, to use dynamite when in a frozen
state.
Dynamite explodes at a temperature of 360° Fahr., and
is very sensitive to friction when hot. In hot countries it
should never be exposed to the rays of the sun. It should,
however, not be kept in a damp or moist place, as this is
liable to cause exudation. Sunlight, if direct, can cause a
slow decomposition, as with all nitro and nitric compounds.
Electric sparks ignite, without exploding it, at least when
operating in the open air.
Dynamite, when made with neutral nitro-glycerine,
appears to keep indefinitely. Sodium or calcium carbonate
to the extent of I per cent, is often added to dynamite to
ensure its being neutral. If it has commenced to undergo
change, however, it rapidly becomes acid, and sometimes
explodes spontaneously, especially if contained in resisting
envelopes. Nevertheless, neutral and well-made dynamite
has been kept for years in a magazine without loss of its
explosive force. If water is brought into contact with it,
the nitro-glycerine is gradually displaced from the silica
(guhr). This action tends to render all wet dynamite
dangerous.
It has been observed that a dynamite made with wood
sawdust can be moistened and then dried without marked
alteration, and from 15 to 20 per cent, of water m-ay be
UNIVERSITY
1 1 8 NITRO-EXPLOSIVES.
added to cellulose dynamite without depriving it of the
power of exploding by strong detonator (this is similar to
wet gun-cotton). It is, however, rendered much less
sensitive to shock. With regard to the power of No. I
dynamite, experiments made in lead cylinders give the
relative value of No. I dynamite, i.o ; blasting gelatine, 1.4 ;
and nitro-glycerine, 1.4. The heat liberated by the sudden
explosion of dynamite is the same as its heat of com-
bustion,* and proportionate to the weight of nitro-glycerine
contained in the mixture. The gases formed are carbonic
acid, water, nitrogen, and oxygen.
The " explosive wave " (of Berthelot) for dynamite is
about 5,000 metres per second. At this rate the explosion
of a cartridge a foot long would only occupy O^JITO part of
a second, while a ton of dynamite cartridges about |
diameter, laid end to end, and measuring one mile in length,
would be exploded in one-quarter of a second by detonating
a cartridge at either end.f Mr C. Napier Hake, F.I.C., the
Inspector of Explosives for the Victorian Government, in
his paper, " Notes on Explosives," says : " The theoretical
efficiency of an explosive cannot in practice be realised in
useful work for several reasons, as for instance in blasting
rock —
" i. Incomplete combustion.
" 2. Compression and chemical changes induced in
surrounding material.
" 3. Energy expended in cracking and heating of the
material which is not displaced.
" 4. The escape of gas through the blast-hole and the
fissures caused by the explosion.
" The useful work consists partly in displacing the
shattered masses. The proportion of useful work obtain-
able has been variously estimated at from 14 to 33 per
cent, of the theoretical maximum potential."
* Berthelot, " Explosives and their Power."
t C. N. Hake, "Notes on Explosives," Jour, Soc, Chem. hid., 1889.
BLASTING GELATINE AND GELATINE DYNAMITE. I IQ
Among the various forms of dynamite that are manu-
factured is carbo-dynamite, the invention of Messrs Walter
F. Reid and W. D. Borland. The base is nitro-glycerine,
and the absorbent is carbon in the form of burnt cork. It
is as cheap as ordinary dynamite, and has greater explosive
force, seeing that 90 per cent, of the mixture is pure nitro-
glycerine, and the absorbent itself is highly combustible.
It is also claimed that if this dynamite becomes wet, no
exudation takes place.
Atlas powder is a dynamite, chiefly manufactured in
America at the Repanno Chemical Works, Philadelphia.
It is a composition of nitro-glycerine, wood-pulp, nitrate of
soda, and carbonate of magnesia. This was the explosive
used in the outrages committed in London, by the so-called
"dynamiters." Different varieties contain from 20 to 75
per cent, of nitro-glycerine.
The Rhenish dynamite, considerably used in the mines
of Cornwall, is composed of 70 parts of a solution of 2 to 3
per cent, of naphthalene in nitro-glycerine, 3 parts of chalk,
7 parts of sulphate of barium, and 20 of kieselguhr.
Kieselguhr dynamites are being largely given up in
favour of gelatine explosives. The late Colonel Cundill,
in his " Dictionary of Explosives," gives a list of about 125
kinds of dynamites. Many of these, however, are not
manufactured. Among the best known after the ordinary
No. i dynamite are forcite, ammonia dynamite, litho-
fracteur, rendock, Atlas powder, giant powder, and the
various explosive gelatines. They all contain nitro-
glycerine, mixed with a variety of other substances, such
as absorbent earths, wood-pulp, nitro-cotton, carbon in
some form or other, nitro-benzol, paraffin, sulphur, nitrates,
or chlorates, &c. &c.
Blasting Gelatine and Gelatine Dynamite. — The
gelatine explosives chiefly in use are known under the
names of blasting gelatine, gelatine dynamite, and gelignite.
They all consist of the variety of nitre-cellulose known as
I2O NITRO-EXPLOSIVES.
collodion-cotton, i.e., a mixture of the penta- and tetra-
nitrates dissolved in nitro-glycerine, and made up with
various proportions of wood-pulp, and some nitrate, or
other material of a similar nature. As the gun-cotton
contains too little oxygen for complete combustion, and
the nitro-glycerine an excess, a mixture of the two
substances is very beneficial.
Blasting gelatine consists of collodion-cotton and nitro-
glycerine without any other substance, and was patented
by Mr Alfred Nobel in 1875. It is a clear, semi-transparent,
jelly-like substance, of a specific gravity of 1.5 to 1.55,
slightly elastic, resembling indiarubber, and generally
consists of 92 per cent, to 93 per cent, of nitro-glycerine,
and 7 to 8 per cent, of nitro-cotton. The cotton from
which it is made should be of good quality. The following
is the analysis of a sample of nitro-cellulose which made
very good gelatine : —
Soluble cotton - - 99.118 per cent.
Gun-cotton - - - 0.642 „
Non-nitrated cotton - - 0.240 „
Nitrogen ----- 11.64 »
Total ash - 0.25 „
The soluble cotton, which is a mixture of the tetra-
and penta-nitrates, is soluble in ether-alcohol, and also in
nitro-glycerine, and many other solvents, whereas the hexa-
nitrate (gun-cotton), C12H14O4(ONO2)6, is not soluble in the
above liquids, although it is soluble in acetone or acetic
ether. It is very essential, therefore, that the nitro-cotton
used in the manufacture of the gelatine explosives should
be as free as possible from gun-cotton, otherwise little
lumps of undissolved nitro-cotton will be left in the
finished gelatine. The non-nitrated or unconverted cotton
should also be very low, in fact considerably under J per
cent.
The nitro-cotton and the nitro-glycerine used should
always be tested before use by the heat test, because if
they do not separately stand this test, it cannot be expected
NITRO-COTTON USED FOR GELATINES. 121
that the gelatine made from them will do so. It often
occurs, however, that although both the ingredients stand
this test separately before being mixed, that after the
process of manufacture one or other or both fail to do so.
The nitro-cotton most suitable for gelatine making is
that which has been finely pulped. If it is not already fine
enough, it must be passed through a fine brass wire sieve.
It will be found that it requires to be rubbed through by
hand, and will not go through at all if in the least degree
damp. It is better, therefore, to dry it first. The per-
centage of nitrogen in the nitrated cotton should be over
1 1 per cent. It should be as free as possible from sand or
grit, and should give but little ash upon ignition, not more
than 0.25 per cent. The cotton, which is generally packed
wet in zinc-lined wooden boxes, will require to be dried, as
it is very essential indeed that none of the materials used
in the manufacture of gelatine should contain more than
the slightest trace of water. If they do, the gelatine sub-
sequently made from them will most certainly exude, and
become dangerous and comparatively valueless. It will
also be much more difficult to make the nitro-cotton
dissolve in the nitro-glycerine if either contains water.
In order to find out how long any sample of cotton
requires to be dried, a sample should be taken from the
centre of several boxes, well mixed, and about 1,000 grms.
spread out on a paper tray, weighed, and the whole then
placed in the water oven at 100° C, and dried for an hour
or so, and again weighed, and the percentage of moisture
calculated from the loss in weight. This will be a guide to
the time that the cotton will probably require to be in the
drying house. Samples generally contain from 20 to 30
per cent, of water. After drying for a period of forty-eight
hours, a sample should be again dried in the oven at 100° C ,
and the moisture determined, and so on at intervals until
the bulk of the cotton is found to be dry, i.e., to contain
from 0.25 to 0.5 per cent, of moisture. It is then ready to
be sifted. During the process of removing to the sifting
122 NITRO-EXPLOSIVES.
house and the sifting itself, the cotton should be exposed
to the air as little as possible, as dry nitro-cotton absorbs
as much as 2 per cent, of moisture from the air at 'ordinary
temperatures and average dryness.
The drying house usually consists of a wooden building,
the inside of which is fitted with shelves, or rather frame-
work to contain drawers, made of wood, with \ brass or
copper wire netting bottoms. A current of hot air is made
to pass through the shelves and over the surface of the
cotton, which is spread out upon them to the depth of
about 2 inches. This current of air can be obtained in any
way that may be found convenient, such as by means of a
fan or Root's blower, the air being passed over hot bricks,
or hot-water pipes before entering the building. The
cotton should also be occasionally turned over by hand in
order that a fresh surface may be continually exposed to
the action of the hot air. The building itself may be
heated by means of hot-water pipes, but on no account
should any of the pipes be exposed. They should all be
most carefully covered over with wood-work, because when
the dry nitro-cotton is moved, as in turning it over, very
fine particles get into the air, and gradually settling on the
pipes, window ledges, &c., may become very hot, when the
slightest friction might cause explosion. It is on this
account that this house should be very carefully swept out
every day. It is also very desirable that the floor of this
house should be covered with oilcloth or linoleum, as being
soft, it lessens the friction.
List shoes should always be worn in this building, and
a thermometer hung up somewhere about the centre of the
house, and one should also be kept in one of the trays to
give the temperature of the cotton, especially the bottom of
the trays. The one nearest to the hot air inlet should be
selected. If the temperature of the house is kept at about
40° C. it will be quite high enough. The building must
of course be properly ventilated, and it will be found very
useful to have the walls made double, and the intervening
COMPOSITION OF GELATINE COMPOUNDS. 123
space filled with cinders, and the roof covered with felt, as
this helps to prevent the loss of heat through radiation, and
to preserve a uniform temperature, which is very desirable.
The dry cotton thus obtained, if not already fine
enough, should be sifted through a brass sieve, and packed
away ready for use in zinc air-tight cases, or in indiarubber
bags. The various gelatine compounds, gelignite, gelatine
dynamite, and blasting gelatine, are manufactured in exactly
the same way. The forms known as gelatine dynamite
differ from blasting gelatine in containing certain pro-
portions of wood-pulp and potassium nitrate, &c. The
following are analyses of some typical samples of the three
compounds : —
Gelatine
Blasting
Gelignite.
Dynamite.
Gelatine.
Nitro-glycerine -
60.514
71.128
92.94 per cent
Nitrocellulose -
4.888
7.632
7.06
Wood-pulp
7.178
4.259
... ,,
Potassium nitrate
27420
16.720
... ,,
Water
0.26l
... ,,
The gelignite and gelatine dynamites consist, therefore,
of blasting gelatine, thickened up with a mixture of absorb-
ing materials. Although the blasting gelatine is weight for
weight more powerful, it is more difficult to make than
either of the other two compounds, it being somewhat
difficult to make it stand the exudation and melting tests.
The higher percentage of nitro-cotton, too, makes it
expensive.
When the dry nitro-cotton, which has been carefully
weighed out in the proportions necessary either for blasting
gelatine or any of the other gelatine explosives, is brought
to the gelatine making house, it is placed in a lead-lined
trough, and the necessary quantity of pure dry nitro-
glycerine poured upon it. The whole is then well stirred
up, and kept at a temperature of from 40° to 45° C. It
should not be allowed to go much above 40° C. ; but
higher temperatures may be used if the nitro-cotton is very
I24
NITRO-EXPLOSIVES.
obstinate,* and will not dissolve. Great caution must,
however, be observed in this case. The mixture should
be constantly worked about by the workman with a wooden
paddle for at least half an hour. At a temperature of 40°
to 45° the nitro-glycerine acts upon the nitro-cotton and
forms a jelly. Without heat the gelatinisation is very im-
perfect indeed, and at temperatures under 40° C. takes
place very slowly.
FIG. 30. — WERNER, PFLEIDEREK, & PERKINS' MIXING MACHINE.
The limit of temperature is 50° C. or thereabouts.
Beyond this the jelly should never be allowed to go, and
to 50° only under exceptional circumstances.
The tank in which the jelly is made is double-lined, in
order to allow of the passage of hot water between its inner
and outer linings. A series of such tanks are generally
built in a wooden framework, and the double linings are
* Generally due to the nitro-cotton being damp.
MIXING JELLY WITH WOOD PULP.
125
made to communicate, so that the hot water can flow from
one to the other consecutively. The temperature of the
water should be about 60" C. if it is intended to gelatinise
at 45° C., and about 80° if at 50° C. ; but this point must,
of course, be found by experiment for the particular plant
used. An arrangement should be made to enable the
FIG. 31. — MR M'RoBERTs' MIXER FOR GELATINE EXPLOSIVES.
workman to at once cut off the supply of hot water and
pass cold water through the tanks in case the explosive
becomes too hot.
The best way to keep the temperature of the water
constant is to have a large tank of water raised upon a
platform, some 5 or 6 feet high, outside the building, which
126 NITRO-EXPLOSIVES.
is automatically supplied with water, and into which steam
is turned. A thermometer stuck through a piece of cork
and floated upon the surface of the tank will give the means
of regulating the temperature.
When the jelly in the tanks has become semi-transparent
and the cotton has entirely dissolved, the mixture should be
transferred to the mixing machine. The mixing machines
are specially designed for this work, and are built in iron,
with steel or bronze kneading- and mixing-blades, according
to requirements.
A suitable machine for the purpose is that known as
the Nito-Universal Incorporator, shown in Fig. 30, which
has been specially constructed by Messrs Werner, Pfleiderer,
& Perkins, Ltd., after many years' experience in the mixing
of explosive materials, and is now almost exclusively adopted
in both Government and private factories. Mr George
M'Roberts'* mixing machine, however, which is shown in
Fig. 31, is still used in some factories for dynamite jelly.
If it is intended to make gelignite, or gelatine dyna-
mite, it is at this point that the proper proportions of
wood-pulpy and potassium nitrate should be added, and
the whole well mixed for at least half an hour, until
the various ingredients are thoroughly incorporated.
* See Jour. Soc. Chem. Ind.^ 1890, 267.
t Most of the wood-pulp used in England is obtained from pine-
trees, but poplar, lime, birch, and beech wood are also used. It is
chiefly imported as wood-pulp. The pulp is prepared as follows : —
The bark and roots are first removed, and the logs then sawn into
boards, from which the knots are removed. The pieces of wood are
afterwards put through a machine which breaks them up into small
pieces about an inch long, which are then crushed between rollers.
These fragments are finally boiled with a solution of sodium bisul-
phite, under a pressure of about 90 Ibs. per square inch, the duration
of the boiling being from ten to twelve hours. Sulphurous acid has
also been used. Pine-wood yields about 45 per cent, and birch
about 40 per cent, of pulp when treated by this process. The pulp is
afterwards bleached and washed, &c.
The following analysis of woods is by Dr H. Miiller : —
MIXING MACHINES FOR GELATINE DYNAMITE. 127
These mixing machines can either be turned by hand,
or a shaft can be brought into the house and the machine
worked by means of a belt at twenty to thirty revolutions
Ufe
T
FIG. 32. — PLAN OF THE Box CONTAINING THE EXPLOSIVE,
IN M'RoBERTs' MACHINE.
per minute. The bearings should be kept constantly
greased and examined, and the explosive mixture care-
fully excluded. When the gelatine mixture has been
thoroughly incorporated, and neither particles of nitrate or
wood meal can be detected in the mass, it should be trans-
ferred to wooden boxes and carried away to the cartridge-
making machines to be worked up into cartridges.
The application of heat in the manufacture of the jelly
from collodion-cotton and nitro-glycerine is absolutely
necessary, unless some other solvent is used besides the
nitro-glycerine, such as acetone, acetic ether, methyl, or
ethyl-alcohol. (They are all too expensive, with the ex-
ception of acetone and methyl-alcohol, for use upon the
large scale.) These liquids not only dissolve the nitro-
Birch.
Beech.
Lime.
Pine.
Poplar.
Cellulose - -
55
•52
4547
53-09
56.99
62.77 per
cent.
Resin - ~ • -
I
.14
0.41
3-93
0.97
1.37
>5
Aqueous extract
2
.65
2.47
3.56
1.26
2.88
55
Water - - -
12
.48
12.57
10.10
13.87
12. IO
55
Lignine -
28.21 39.14 29.32 26.91 20.88
128
NITRO-EXPLOSIVES.
cellulose in the cold, but render the resulting gelatine
compound less sensitive to concussion, and reduce its
quickness of explosion (as in cordite). They also lower
the temperature at which the nitro-glycerine becomes con-
gealed, i.e., they lower the freezing point* of the resulting
gelatine.
The finished gelatine paste, upon entering the cartridge
huts, is at once transferred to the cartridge-making machine,
which is very like an ordinary sausage-making machinef
(Fig. 33). The whole thing must be made of gun-metal
FIG. 33. — CARTRIDGE-MAKING MACHINE FOR GELATINE EXPLOSIVES.
or brass, and it consists of a conical case containing a
shaft and screw. The revolutions of the shaft cause the
thread of the screw to push forward the gelatine introduced
by the hopper on the top to the nozzle, the apex of the
cone-shaped case, from whence the gelatine issues as a con-
tinuous rope. The nozzle is of course of a diameter accord-
ing to the size of cartridge required.
The issuing gelatine can of course be cut off at any
length. This is best done with a piece of hard wood
planed down to a cutting edge, i.e., wedge-shaped. Mr
Trench has devised a kind of brass frame, into which the
gelatine issuing from the nozzle of the cartridge machine
is forced, finding its way along a series of grooves. When
* It has been proposed to mix dynamite with amyl alcohol for
this purpose. Di-nitro-mono-chlorhydrine has also been proposed.
t G. M* Roberts, Jour. Soc. Chem. Ind., 3151 March 1890, p. 266.
CARTRIDGE-MAKING MACHINE. 129
the frame is full, a wooden frame, which is hinged to one
end of the bottom frame, and fitted with a series of brass
knives, is shut down, thereby cutting the gelatine up into
lengths of about 4 inches.
It is essential that the cartridge machines should have
no metallic contacts inside. The bearing for the screw
shaft must be fixed outside the cone containing the
gelatine. One of these machines can convert from 5 to
10 cwt. of gelatine into cartridges per diem, depending
upon the diameter of the cartridges made.
After being cut up into lengths of about 3 inches, the
gelatine is rolled up in cartridge paper. Waterproof paper
is generally used. The cartridges are then packed away
in cardboard boxes, which are again packed in deal boxes
lined with indiarubber, and screwed down air tight, brass
screws or zinc or brass nails being used for the purpose.
These boxes are sent to the magazines. Before the boxes
are fastened down a cartridge or so should be removed
and tested by the heat test, the liquefaction test, and the
test for liability to exudation. (Appendix, p. 6, Explo-
sives Act, 1875.) A cartridge also should be stored in the
magazine in case of any subsequent dispute after the
bulk of the material has left the factory.
The object of the liquefaction test is to ensure that
the gelatine shall be able to withstand a fairly high tem-
perature (such as it might encounter in a ship's hold)
without melting or running together. The test is carried
out as follows: — A cylinder of the gelatine dynamite is
cut from the cartridge of a length equal to its diameter.
The edges must be sharp. This cylinder is to be placed
on end on a flat surface (such as paper), and secured by
a pin through the centre, and exposed for 144 consecutive
hours to a temperature of 85° to 90° F., and during such
time the cylinder should not diminish in height by more
than one-fourth of an inch, and the cut edges should
remain sharp. There should also be no stain of nitro-
glycerine upon the paper.
I
130 NITRO-EXPLOSIVES.
The exudation test consists in freezing and thawing
the gelatine three times in succession. Under these con-
ditions there should be no exudation of nitro-glycerine.
All the materials used in the manufacture of gelatine ex-
plosives should be subjected to analytical examination
before use, as success largely depends upon the purity of
the raw materials. The wood-pulp, for instance, must be
examined for acidity.
Properties of the Gelatine Compounds. — Blasting
gelatine is generally composed of 93 to 95 parts nitro-
glycerine, and 5 to 7 parts of nitre-cellulose, but the
relative proportions of explosive base and nitro-glycerine,
&c., in the various forms of the gelatine explosives do not
always correspond to those necessary for total combustion,
either because an incomplete combustion gives rise to a
greater volume of gas, or because the rapidity of decomposi-
tion and the law of expansion varies according to the
relative proportions and the conditions of application. The
various additions to blasting gelatine generally have the
effect of lowering the strength by reducing the amount of
nitro-glycerine, but this is sometimes done in order to
change a shattering agent into a propulsive force. If this
process be carried too far, we of course lose the advantages
due to the presence of nitro-glycerine. There is therefore
a limit to these additions.*
The homogeneousness and stability of the mixture are
of the highest importance. It is highly essential that the
nitro-glycerine should be completely absorbed by the
substances with which it is mixed, and that it should not
subsequently exude when subjected to heat or damp. It
is also important that there should be no excess of nitro-
glycerine, as this may diminish instead of augment the
strength, owing to a difference in the mode of the propaga-
* Mica is said to increase the rapidity of explosion when mixed
with gelatine.
PROPERTIES OF GELATINE COMPOUNDS. 131
tion of the explosive wave in the liquid and in the mixture.
Nitro-glycerine at its freezing point has a tendency to
separate from its absorbing material, in fact to exude.
When frozen, too, it requires a more powerful detonation
to explode it, but it is less sensitive to shock. The specific
gravity of blasting gelatine is 1.5 (i.e., nearly equal to that
of nitro-glycerol) ; that of gun-cotton (dry) is i.o.
Blasting gelatine burns in the air when unconfined
without explosion, at least in small quantities and when
not previously heated, but it is rather uncertain in this
respect. It can be kept at a moderately high temperature
(70° C.) ^without decomposition. At higher temperatures
the nitro-glycerine will partially evaporate. When slowly
heated, it explodes at 204° C. If, however, it contains as
much as 10 per cent, of camphor, it burns without exploding.
According to Berthelot,* gelatine composed of 91.6 per
cent nitro-glycerine and 8.4 per cent, of nitro-cellulose,
which are the proportions corresponding to total combus-
tion, produces by explosion I77CO2+ I43H2O + 8N2.
He takes C24H22(NO3H)9O11 as the formula of the
nitro-cellulose, and 5iC3H2(NO8H)3 + C24H22(NO3H)9On as
the formula of the gelatine itself, its equivalent weight being
12,360 grms. The heat liberated by its explosion is equal
to 19,381 calories, or for I kilo. 1,535 calories. Volume of
gases reduced temperature equals 8,950 litres. The relative
value f of blasting gelatine to nitro-glycerne is as 1.4 to 1.45,
kieselguhr dynamite being taken as i.o.
* Berthelot, " Explosives and their Powers."
t Roux and Sarran.
CHAPTER V.
NITRO-BENZOL, ROBURITE, BELLITE,
PICRIC ACID, crv.
Explosives derived from Benzene — Toluene and Nitro-Benzene — Di- and Tri-
nitro-Benzene — Roburite : Properties and Manufacture — Bellite : Proper-
ties, &c. — Securite — Tonite No. 3. — Nitro-Toluene— Nitro-Naphthalene
— Ammonite — Sprengel's Explosives — Picric Acid — Picrates — Picric
Powders — Melinite — Abel's Mixture — Brugere's Powders — The Fulmin-
ates— Composition, Formula, Preparation, Danger of, &c. — Detonators :
Sizes, Composition, Manufacture — Fuses, &c.
The Explosives derived from Benzene. — There is a large
class of explosives made from the nitrated hydro-carbons —
benzene, C6H6; toluene, C7H8 ; naphthalene, C10HS ; and also
from phenol (or carbolic acid), CCH5OH. The benzene
hydro-carbons are generally colourless liquids, insoluble in
water, but soluble in alcohol and ether. They generally distil
without decomposition. They burn with a smoky flame,
and have an ethereal odour. They are easily nitrated and
sulphurated ; mono, di, and tri derivatives are readily
prepared, according to the strength of the acids used. It
is only the H-atoms of the benzene nucleus which enter
into reaction.
Benzene was discovered by Faraday in 1825, and
detected in coal-tar by Hofmann in 1845. It can be
obtained from that portion of coal-tar which boils at 80°
to 85° by fractionating or freezing.* The ordinary benzene
of commerce contains thiophene (C4H4S), from which it
may be freed by shaking with sulphuric acid. Its boiling
* It may be prepared chemically pure by distilling a mixture of
benzoic acid and lime.
NITRO-BENZENES.
133
point is 79° C. ; specific gravity at o° equals 0.9. It burns
with a luminous smoky flame, and is a good solvent for
fats, resins, sulphur, phosphorus, &c. Toluene was dis-
covered in 1837, and is prepared from coal-tar. It boils
at 110° C., and is still liquid at 28° C.
The mono-, chloro-, bromo-, and iodo-benzenes are
colourless liquids of peculiar odour. Di-chloro-, di-bromo-
benzenes, tri- and hexa-chloro- and bromo-benzenes, are
also known ; and mono-chloro-, CGH4C1(CH3), and bromo-
toluenes, together with di derivatives in the ortho, meta,
and para modifications. The nitro-benzenes and toluenes
are used as explosives. The following summary is taken
from Dr A. Bernthsen's " Organic Chemistry " : —
SUMMARY.
C(iH5(NOo) CGH4(N02)2 CBHs(NOs)8
Nitrobenzene. Ortho-, meta-, and para- S.-Tri-nitro-benzene.
Liq. E.Pt. 206° C. di-nitro-benzenes. Solid. Solid. M.P. 121° C.
M.P. ii8°, 90°, and 172° C.
C6H4(CH,)N02
Ortho-, meta-, and para-
nitro-toluenes.
B.P. 218°, 230% and 234° C.
Para compound solid.
C6H3(CHs)(NOa),
Di-nitro-toluenes.
C6H3(CH3)N0.2
Nitro-xylene.
Liquid.
C0H2(CH3)3N02
Nitro-mesitylene.
Solid.
C6H4C1(N02) C(iBr4(N02)2
Nitro-chloro-benzenes. Tetra-bromo-di-nitro-
benzene.
The nitro compounds are mostly pale yellow liquids,
which distil unchanged, and volatilise with water vapour,
or colourless or pale yellow needles or prisms. Some of
them, however, are of an intense yellow colour. Many of
them explode upon being heated. They are heavier than
water, and insoluble in it, but mostly soluble in alcohol,
ether, and glacial acetic acid.
Nitro-benzene, CGH5(NO2), was discovered in 1834 by
Mitscherlich. It is a yellow liquid, with a melting point
of +3° C. It has an intense odour of bitter almonds. It
1 34 NITRO-EXPLOSIVES.
solidifies in the cold. In di-nitro-benzene, the two nitro
groups may be in the meta, ortho, or para position, the
meta position being the most general (see fig., page 4).
By recrystallising from alcohol, pure meta-di-nitro-benzene
may be obtained in long colourless needles. The ortho
compound crystallises in tables, and the para in needles.
They are both colourless. When toluene is nitrated, the
para and ortho are chiefly formed, and a very little of the
meta compound.
Nitro Compounds of Benzene and Toluene. — The
preparation of the nitro derivatives of the hydrocarbons
of the benzene series is very simple. It is only necessary
to bring the hydrocarbon into contact with strong nitric
acid, when the reaction takes place, and one or more of
the hydrogen atoms of the hydrocarbon are replaced by
the nitryl group (NO9). Thus by the action of nitric acid
on benzene (or benzol), mono-nitro-benzene is formed : —
CGH0+ HNO3 = CGH5.NO2+ H2O.
Mono-nitro-benzene.
By the action of another molecule of nitric acid, the di-
nitro-benzene is formed :—
C6H5.NO, + HN08 = CGH4(N02)2 + H2O.
Di-nitro-benzene.
These nitro bodies are not acids, nor are they ethereal
salts of nitrous acid, as nitro-glycerine is of glycerine.
They are regarded as formed from nitric acid by the
replacement of hydroxyl by benzene radicals.
Mono-nitro Benzene is made by treating benzene with
concentrated nitric acid, or a mixture of nitric and sulphuric
acids. The latter, as in the case of the nitration of glycerine,
takes no part in the reaction, but only prevents the dilution
of the nitric acid by the water formed in the reaction.
Small quantities may be made thus: — Take 150 c.c. of
H9SO4 and 75 c.c. HNO3, or I part nitric to 2 parts
DI-NITRO BENZENE. 135
sulphuric acid, and put in a beaker standing in cold water ;
then add 15 to 20 c.c. of benzene, drop by drop, waiting
between each addition for the completion of the reaction,
and shake well during the operation. When finished, pour
contents of beaker into about a litre of cold water ; the
nitro-benzol will sink to the bottom. Decant the water,
and wash the nitro-benzol two or three times in a separating
funnel with water. Finally, dry the product by adding a
little granulated calcium chloride, and allowing to stand for
some little time, it may then be distilled. Nitro-benzene
is a heavy oily liquid which boils at 205° C., has a specific
gravity of 1.2, and an odour like that of oil of bitter almonds.
In the arts it is chiefly used in the preparation of aniline.
Di-nitro Benzene is a product of the further action of
nitric acid on benzene or nitro-benzene. It crystallises in*
long fine needles or thin rhombic plates, and melts at 89.9°
C. It can be made thus : — The acid mixture used consists
of equal parts of nitric and sulphuric acids, say 50 c.c. of
each, and without cooling add very slowly 10 c.c. of benzene
from a pipette. After the action is over, boil the mixture
for a short time, then pour into about half a litre of water,
filter off the crystals thus produced, press between layers of
filter paper, and crystallise from alcohol. Di-nitro-benzene,
or meta-di-nitro-benzene, as it is sometimes called, enters
into the composition of several explosives, such as tonite
No. 3, roburite, securite, bellite.
Nitro-benzene is manufactured upon the large scale as
follows : — Along a bench a row of glass flasks, containing I
gallon each (i to 2 Ibs. benzene), are placed, and the acids
added in small portions at a time, the workmen com-
mencing with the first, and adding a small quantity to each
in turn, until the nitration was complete. This process was
a dangerous one, and is now obsolete. The first nitro-
benzene made commercially in England, by Messrs Simpson,
Maule, and Nicholson, of Kennington, in 1856, was by this
process. Now, however, vertical iron cylinders, made of
1 36 NITRO-EXPLOSIVES.
cast-iron, are used for the nitrating operation. They are
about 4 feet in diameter and 4 feet deep, and a series are
generally arranged in a row, at a convenient height from
the ground, beneath a line of shafting. Each cylinder is
covered with a cast-iron lid having a raised rim all round.
A central orifice gives passage to a vertical shaft, and two
or more other conveniently arranged openings allow the
benzene and the mixed acids to flow in. Each of these
openings is surrounded with a deep rim, so that the whole
top of the cylinder can be flooded with water some inches
in depth, without any of it running into the interior of the
nitrator. The lid overhangs the cylinder somewhat, and in
the outer rim a number of shot-holes or tubes allow the
water to flow down all over the outside of the cylinder into
a shallow cast-iron dish, in which it stands. By means of
a good supply of cold water, the top, sides, and bottom of
the whole apparatus is thus cooled and continually flooded.
The agitator consists of cast-iron arms keyed to a vertical
shaft, with fixed arms or dash-plates secured to the sides
of the cylinder. The shaft has a mitre wheel keyed on the
top, which works into a corresponding wheel on the hori-
zontal shafting running along the top of the converters.
This latter is secured to a clutch ; and there is a feather on
the shaft, so that any one of the converters can if necessary
be put either in or out of gear. This arrangement is neces-
sary, as riggers or belts of leather, cotton, or indiarubber
will not stand the atmosphere of the nitro-benzole house.
Above and close to each nitrator stands its acid store tank,
of iron or stoneware.
The building in which the nitration is carried out should
consist of one story, have a light roof, walls of hard brick,
and a concrete floor of 9 to 12 inches thick, and covered
with pitch, to protect its surface from the action of the
acids. The floor should be inclined to a drain, to save any
nitro-benzol spilt. Fire hydrants should be placed at con-
venient places, and it should be possible to at once fill the
building with steam. A 2-inch pipe, with a cock outside
MANUFACTURE OF NITROBENZENE. 137
the building, is advisable. The building should also be as
far as possible isolated.
The acids are mixed beforehand, and allowed to cool
before use. The nitric acid used has a specific gravity of
1.388, and should be as free as possible from the lower
oxides of nitrogen. The sulphuric acid has a specific
gravity of 1.845, and contains from 95 to 96 per cent, of
mono-hydrate. A good mixture is — 100 parts of nitric to
140 parts of sulphuric acid, and 78 parts of benzene ; or 128
parts HNO3, 179 of H2SO4, and 100 of benzene (C6H6).
The benzene having been introduced into the cylinder, the
water is turned on and the apparatus cooled, the agitators
are set running, and the acid cock turned on so as to allow
it to flow in a very thin stream into the nitrator.
Should it be necessary to check the machinery even for
a moment, the stream of acid must be stopped and the
agitation continued for some time, as the action proceeds
with such vigour that if the benzene being nitrated comes
to rest and acid continues to flow, local heating occurs, and
the mixture may inflame. Accidents from this cause have
been not infrequent. The operation requires between eight
to ten hours, agitation and cooling being kept up all the
time. When all the acid is added the water is shut off, and
the temperature allowed to rise a little, to about 100° C.
When it ceases to rise the agitators are thrown out of gear,
and the mixture allowed some hours to cool and settle,
The acid is then drawn off, and the nitro-benzene is well
washed with water, and sometimes distilled with wet steam,
to recover a little unconverted benzene and a trace of
paraffin (about .5 per cent, together). At many English
works, 100 to 200 gallons, or 800 to 1,760 Ibs., are nitrated
at a time, and toluene is often used instead of benzene,
especially if the nitro-benzene is for use as essence of
myrbane. The waste acids, specific gravity 1.6 to 1.7, con-
tain a little nitro-benzene in solution and some oxalic acid.
They are concentrated in cast-iron pots and used over
again.
138 NITRO-EXPLOSIVES.
Di-nitro Benzene is obtained by treating a charge of
the hydrocarbon benzene with double the quantity of mixed
acids in two operations, or rather in two stages, the second
lot of acid being run in directly after the first. The cooling
water is then shut ofif, and the temperature allowed to rise
rapidly, or nitro-benzene already manufactured is taken and
again nitrated with acids. A large quantity of acid fumes
come off, and some of the nitro- and di-nitro-benzol pro-
duced comes off at the high temperature which is attained,
and a good condensing apparatus of stoneware must be
used to prevent loss. The product is separated from the
acids, washed with cold water and then with hot. It is
slightly soluble in water, so that the washing waters must
be kept and used over again. Finally it is allowed to
settle, and run while still warm into iron trays, in which it
solidifies in masses 2 or 4 inches thick. It should not
contain any nitro-benzol, nor soil a piece of paper when
laid on it, should be well crystallised, fairly hard, and
almost odourless. The chief product is meta-di-nitro-
benzene, melting point 89.8, but ortho-di-nitro-benzene,
melting point 118°, and para-di-ditro, melting point 172°,
are also produced. The melting point of the commercial
product is between 85° to 87° C.
Di-nitro-toluene is made in a similar manner. The tri-
nitro-benzene can only be made by using a very large
excess of the mixed acids. Nitro-benzene, when reduced
with iron, zinc, or tin, and hydrochloric acids, forms aniline.
Roburite. — This explosive is the invention of a German
chemist, Dr Carl Roth (English patent 267 A, 1887), and is
now manufactured in England, at Gathurst, near Wigan.
It consists of two component parts, non-explosive in them-
selves (Sprengel's principle), but which, when mixed, form
a powerful explosive. The two substances are ammonium
nitrate and chlorinated di-nitro-benzol. Nitro-naphthalene
is also used. Nitrate of soda and sulphate of ammonium
are allowed to be mixed with it. The advantages claimed
/ V OF THE
// - 1 % i f* !O ^
•
ROBURITE. 139
for the introduction of chlorine into the nitro compound
are that chlorine exerts a loosening effect upon the NO2
groups, and enables the compound to burn more rapidly
than when the nitro groups alone are present
The formula of chloro-di-nitro-benzol is C0H3C1(NO2)2.
The theoretical percentage of nitrogen, therefore, is 13.82,
and of chlorine 17.53. Dr Roth states that, from experi-
ments he has made, the dynamic effect is considerably
increased by the introduction of chlorine into the nitro
compound. Roburite burns quickly, and is not sensitive
to shock ; it must be used dry ; it cannot be made to
explode by concussion, pressure, friction, fire, or lightning ;
it does not freeze ; it does not give off deleterious fumes,
and it is to all intents and purposes flameless ; and when
properly tamped and fired by electricity, can be safely used
in fiery mines, neither fine dust nor gases being ignited by
it. The action is rending and not pulverising. Compared
to gunpowder, it is more powerful in a ratio ranging from
2\ to 4 to I, according to the substance acted upon. It is
largely used in blasting, pit sinking, quarrying, &c., but
especially in coal mining. According to Dr Roth, the
following is the equation of its decomposition : —
In appearance roburite is a brownish yellow powder,
with the characteristic smell of nitro-benzol. Its specific
gravity is 1.40. The Company's statement that the fumes
of roburite were harmless having been questioned by the
miners of the Garswood Coal and Iron Works Colliery, a
scientific committee was appointed by the management
and the men jointly for the purpose of settling the question.
The members of this committee were Dr N. Hannah, Dr
D. J. Mouncey, and Professor H. B. Dixon, F.R.S., of
Owens College. After a protracted investigation, a long
and technical report was issued, completely vindicating the
innocuousness of roburite when properly used. In the
words of T/ie Iron arid Coal Trades' Review (May 24,
140 NITRO-EXPLOSIVES.
1889), "The verdict, though not on every point in favour
of the use in all circumstances of roburite in coal mines, is
yet of so pronounced a character in its favour as an ex-
plosive that it is impossible to resist the conclusion that
the claims put forward on its behalf rest on solid grounds."
Roburite was also one of the explosives investigated
by the committee appointed in September 1889 by the
Durham Coalowners' and Miners' Associations, for the
purpose of determining whether the fumes produced by
certain explosives are injurious to health. Both owners
and workmen were represented on the committee, which
elected Mr T. Bell, H.M. Inspector of Mines, as its chair-
man, with Professor P. P. Bedson and Drs Drummond and
Hume as professional advisers. The problem considered
was whether the fumes produced by the combustion of
certain explosives, one of which was roburite, were injurious
to health. The trial comprised the chemical analysis of
the air at the " intake," and of the vitiated air during the
firing of the shots at the " return," and also of the smoky
air in the vicinity of the shot-holes. Five pounds and a
half of roburite were used in twenty-three shots. It had
been asserted that the fumes from this explosive contained
carbon-monoxide, CO, but no trace of this gas could be
discovered after the explosion. On another occasion, how-
ever, when 4.7 Ibs. of roburite were exploded in twenty-
three shots, the air at the " return " showed traces of CO
gas to the extent of .042 to .019 per cent. The medical
report which Drs Hume and Drummond presented to the
committee shows that they investigated every case of sus-
pected illness produced by exposure to fumes, and they
could find no evidence of acute illness being caused. They
say, " No case of acute illness has, throughout the inquiry,
been brought to our knowledge, and we are led to the con-
clusion that such cases have not occurred."
Manufacture. — As now made, roburite is a mixture of
ammonium nitrate and chlorinated di-nitro-benzol. The
ROBURITE. 14!
nitrate of ammonia is first dried and ground, and then
heated in a closed steam-jacketed vessel to a temperature
of 80° C., and the melted organic compound is added, and
the whole stirred until an intimate mixture is obtained.
On cooling, the yellow powder is ready for use, and is
stored in straight canisters or made up into cartridges.
Owing to the deliquescent nature of the nitrate of ammonia,
the finished explosive must be kept out of contact with the
air, and for this reason the cartridges are waterproofed by
dipping them in melted wax. Roburite is made in Ger-
many, at Witten, Westphalia; and also at the English Com-
pany's extensive works at Gathurst, near Wigan, which have
been at work now for some eighteen years, having started
in 1888. These works are of considerable extent, covering
30 acres of ground, and are equal to an output of 10 tons
a day. A canal runs through the centre, separating the
chemical from the explosive portions of the works, and the
Lancashire and Yorkshire Railway runs up to the doors.
Besides sending large quantities of roburite itself abroad,
the Company also export to the various colonies the two
components, as manufactured in the chemical works, and
which separately are quite non-explosive, and which, having
arrived at their destination, can be easily mixed in the
proper proportions.
Among the special advantages claimed for roburite
are : — First, that it is impossible to explode a cartridge
by percussion, fire, or electric sparks. If a cartridge or
layer be struck with a heavy hammer, the portion struck is
decomposed, owing to the large amount of heat developed
by the blow. The remaining explosive is not in the least
affected, and no detonation whatever takes place. If
roburite be mixed with gunpowder, and the gunpowder
fired, the explosion simply scatters the roburite without
affecting it in the least. In fact, the only way to explode
roburite is to detonate it by means of a cap of fulminate,
containing at least I gramme of fulminate of mercury.
Secondly, its great safety for use in coal mines. Roburite
142 NITRO-EXPLOSIVES.
has the great advantage of exploding by detonation at a
very low temperature, indeed so low that a very slight
amount of tamping is required when fired in the most
explosive mixture of air and coal gas possible, and not at
all in a mixture of air and coal dust — a condition in which
the use of gunpowder is highly dangerous.
Mr W. J. Orsman, F.I.C., in a paper read at the Uni-
versity College, Nottingham, in 1893, gives the temperature
of detonation of roburite as below 2,100° C, and of ammo-
nium nitrated as 1,130° C., whereas that of blasting gelatine
is as much as 3,220° C. With regard to the composition
of the fumes formed by the explosion of roburite, Mr
Orsman says : " With certain safety explosives — roburite,
for instance — an excess of the oxidising material is added,
namely, nitrate of ammonia ; but in this case the excess of
oxygen here causes a diminution of temperature, as the
nitrate of ammonia on being decomposed absorbs heat
This excess of oxygen effectually prevents the formation of
carbon monoxide (CO) and the oxides of nitrogen."
The following table (A), also from Mr Orsman's paper,
gives the composition of five prominent explosives, and
shows the composition of the gases formed on explosion.
The gases were collected after detonating 10 grms. of each
in a closed strong steel cylinder, having an internal diameter
of 5 inches.
With respect to the influence of ammonium nitrate in
lowering the temperature of explosion of the various sub-
stances to which it is added, it was found by a French
Commission that, when dry and finely powdered, ammo-
nium nitrate succeeds in depreciating the heat of decom-
position without reducing the power of the explosive below
a useful limit. The following table (B) shows the composi-
tion of the explosives examined, and the temperatures
which accompanied their explosion.
Bellite is the patent of Mr Carl Lamm, Managing
Director of the Rotebro Explosive Company, of Stockholm,
COMPOSITION OF FIVE EXPLOSIVES.
Explosive.
Volume
of Gas
formed.
Composition of Gases.
CO2.
CO.
CH4&H.
N.
Per
Per
Per
Per
c.c.
cent.
cent.
cent.
cent.
Gunpowder — ^
Nitre - 75 parts |
Sulphur - - 10 ,, f
Charcoal - - 15 „ )
2,214
51-3
3-5
3-5
41.7
Gelignite — x
Nitro-glycerine 56.5 parts
Nitro-cotton - 3.5 „
Wood-meal - 8.0 „
4,980
25
7
...
67
KNO3 - - 32.0 „ J
Tonite— )
Nitro-Cotton
3,75°
30
8
62
Barium nitrate )
Roburite — \
Ammonium nitrate, 86 parts 1
Di-nitro-chloro- j
4,780
32
...
...
68
benzol - - 14 „;
Carbonite ^
Nitro-glycerine 25 parts |
Wood-meal - 40 „ f
2,100
19
15
26
Potas. nitrate - 34 „ J
B
Original
Percentage
Final
Explosive.
Temperature
NH4.N03
Temperature
Co-efficient.
added.
Co-efficient.
Nitro-glycerine
3,200
Blasting gelatine (8 per cent. 1
gun-cotton) - - - j
3,090
88
M93
Dynamite (25 per cent. \
silica) - - - J
2,940
80
1,468
Gun-cotton, i
2,650
2,060
90.5
1,450
Ammonium nitrate
1,130
144 NlTRO-EXPLOSIVES.
and is licensed for manufacture in England. It consists of
a mixture of nitrate of ammonia with di- or tri-nitro-benzol,
it has a specific gravity of 1.2 to 1.4 in its granulated state,
and I litre weighs 800 to 875 grms. Heated in an open
vessel, bellite loses its consistency at 90° C, but does not
commence to separate before a temperature of 200° C. is
reached, when it evaporates without exploding. If heated
suddenly, it burns with a sooty flame, somewhat like tar,
but if the source of heat is removed, it will cease burning,
and assume a caramel-like structure. It absorbs very little
moisture from the air after it has been pressed, and if the
operation has been performed while the explosive is hot,
the subsequent increase of weight is only 2 per cent. When
subjected to the most powerful blow with a steel hammer
upon an iron plate, it neither explodes nor ignites. A rifle
bullet fired into it at 50 yards' distance will not explode it.
Granulated bellite explodes fully by the aid of fulminating
mercury. Fifteen grms. of bellite fired by means of ful-
minate, projected a shot from an ordinary mortar, weigh-
ing 90 Ibs., a distance of 75 yards, 15 grms. of gunpowder,
under the same conditions, throwing it only 12 yards. A
weight of /J Ibs. falling 145 centimetres failed to explode
I grm. of bellite.
Various experiments and trials have been made with
this explosive by Professor P. T. Cleve, M. P. F. Chalon,
C. N. Hake, and by a committee of officers of the Swedish
Royal Artillery. It is claimed that it is a very powerful
and extremely safe explosive ; that it cannot be made to
explode by friction, shock, or pressure, nor by electricity,
fire, lightning, &c., and that it is specially adapted for use
in coal mines, &c. ; that it can only be exploded by means
of a fulminate detonator, and is perfectly safe to handle and
manufacture ; that it does not freeze, can be used as a
filling for shells, and lastly, can be cheaply manufactured.
Securite consists of 26 parts of meta-di-nitro-benzol
and 74 parts of ammonium nitrate. It is a yellow powder,
SECURITE AND KINETITE. 145
with an odour of nitro-benzol. It was licensed in 1886. It
sometimes contains tri-nitro-benzol, and tri-nitro-naphtha-
lene. The equation of its combustion is given as
C6H42NO2+io(NH4NO3) = 6CO2 + 22H2O + N2
and, like bellite and roburite, it is claimed to be perfectly
safe to use in the presence of fire damp and coal dust*
The variety known as Flameless Securite consists of a mix-
ture of nitrate and oxalate of ammonia and di-nitro-benzol.
Kinetite. — A few years ago an explosive called " Kine-
tite " f was introduced, but is not manufactured in England.
It was the patent of Messrs Petry and Fallenstein, and con-
sisted of nitro-benzol, thickened or gelatinised by the
addition of some collodion-cotton, incorporated with finely
ground chlorate of potash and precipitated sulphide of
antimony. An analysis gave the following percentages : —
Nitro-benzol, 19.4 per cent.
Chlorate of potash, 76.9 per cent.
Sulphide of antimony nitro-cotton, 3.7 per cent.
It requires a very high temperature to ignite it, and cannot,
under ordinary circumstances, when unconfined, be ex-
ploded by the application of heat. It is little affected by
immersion in water, unless prolonged, when the chlorate
dissolves out, leaving a practical inexplosive residue.^ It
was found to be very sensitive to combined friction and
percussion, and to be readily ignited by a glancing blow
of wood upon wood. It was also deficient in chemical
stability, and has been known to ignite spontaneously both
* See paper by S. B. Coxon, North of Ens;. Inst. Mining and Me ch.
Eng., 11,2, 87.
t V. Watson Smith, Jour. Soc. Chem. Ind., January 1887.
\ Col. Cundill, R.A., " Diet, of Explosives," says : "If, however, it
be exposed to moist and dry air alternately, the chlorate crystallises
out on the surfaces, and renders the explosive very sensitive."
K
146 NITRO-EXPLOSIVES.
in the laboratory and in a magazine. It is an orange-
coloured plastic mass, and smells of nitro-benzol.
Tonite No. 3 contains 10 to 14 per cent, of nitro-benzol
(see Tonite). Trench's Flameless Explosive contains 10
per cent, of di-nitro-benzol, together with 85 per cent, of
nitrate of ammonia, and 5 per cent, of a mixture of alum,
and the chlorides of sodium and ammonia.
Tri-nitro-Toluene. — Toluene, C7H8, now chiefly ob-
tained from coal-tar, was formerly obtained by the dry
distillation of tolu-balsam. It may be regarded as methyl-
benzene, or benzene in which one hydrogen is replaced by
methyl (CH3), thus (C6H5CH3), or as phenyl-methane, or
methane in which one hydrogen atom is replaced by the
radical phenyl (C6H5), thus (CH3C6H5). Toluene is a
colourless liquid, boiling at 1 10° C, has a specific gravity
of .8824 at o° C., and an aromatic odour. Tri-nitro-toluene
is formed by the action of nitric acid on toluene. Accord-
ing to Haussermann, it is more advantageous to start with
the ortho-para-di-nitro-toluene, which is prepared by allow-
ing a mixture of 75 parts of 91 to 92 per cent, nitric acid
and 1 50 parts of 95 to 96 per cent, sulphuric acid to run
in a thin stream into 100 parts of para-nitro-toluene, while
the latter is kept at a temperature between 60° to 65° C.,
and continually stirred. When the acid has all been run
in, this mixture is heated for half an hour to 80° C., and
allowed to stand till cold. The excess of nitric acid is then
removed. The residue after this treatment is a homogene-
ous crystalline mass of ortho-para-di-nitro-toluene, of which
the solidifying point is 69.5° C. To convert this mass into
tri-nitro derivative, it is dissolved by gently heating it with
four times its weight of sulphuric acid (95 to 96 per cent),
and it is then mixed with li times its weight of nitric acid
(90 to 92 per cent.), the mixture being kept cool. After-
wards it is digested at 90° to 95° C., with occasional stirring,
until the evolution of gas ceases. This takes place in about
four or five hours.
FAVERSHAM POWDER. 147
The operation is now stopped, the product allowed to
cool, and the excess of nitric acid separated from it. The
residue is then washed with hot water and very dilute soda
solution, and allowed to solidify without purification. The
solidifying point is 70° C., and the mass is then white, with
a radiating crystalline structure. Bright sparkling crystals,
melting at 81.5° C. may, however, be obtained by recrystal-
lisation from hot alcohol. The yield is from 100 parts di-
nitro-toluene, 1 50 parts of the tri-nitro derivative. Hausser-
mann states also that 1:2:4:6 tri-nitro-toluene can be
obtained from ordinary commercial di-nitro-toluene melt-
ing at 60° to 64° C. ; but when this is used, greater pre-
cautions must be exercised, for the reactions are more
violent. Moreover, 10 per cent, more nitric acid is required,
and the yield is 10 per cent. less. He also draws attention
to the slight solubility of tri-nitro-toluene in hot water, and
to the fact that it is decomposed by dilute alkalies and
alkaline carbonates — facts which must be borne in mind
in washing the substance. This material is neither difficult
nor dangerous to make. It behaves as a very stable sub-
stance when exposed to the air under varying conditions
of temperature (—10° to +50° C.) for several months. It
cannot be exploded by flame, nor by heating it in an open
vessel. It is only slightly decomposed by strong percus-
sion on an anvil. A fulminate detonator produces the
best explosive effect with tri-nitro-toluene. It can be used
in conjunction with ammonium nitrate, but such admixture
weakens the explosive power ; but even then it is stated to
be stronger than an equivalent mixture of di-nitro-benzene
and ammonium nitrate. Mowbray patented a mixture of
3 parts nitro-toluol to 7 of nitre-glycerine, also in the
proportions of I to 3, which he states to be a very safe
explosive.
Faversham Powder. — One of the explosives on the
permitted list (coal mines) is extensively used, and is
manufactured by the Cotton Powder Co. Ltd. at Faver-
148 NITRO-EXPLOSIVES.
sham. It is composed of tri-nitro-toluol 1 1 parts, ammo-
nium nitrate 93 parts, and moisture I part. This explosive
must be used only when contained in a case of an alloy of
lead, tin, zinc, and antimony thoroughly waterproof; it
must be used only with a detonator or electric detonator
of not less strength than that known as No. 6.
Nitro-Naphthalene. — Nitro-naphthalene is formed by
the action of nitric acid on naphthalene (C10H8). Its formula
is C10H7NO2, and it forms yellow needles, melting at 61° C. ;
and of di-nitro-naphthalene (C10H6(NO.2)2), melting point
216° C. There are also tri-nitro and tetra-nitro and a and /3
derivatives of nitro-naphthalene. It is the di-nitro-naphtha-
lene that is chiefly used in explosives. It is contained in
roburite, securite, romit, Volney's powder, &c. Fehven has
patented an explosive consistingof TO parts of nitro-naphtha-
lene mixed with the crude ingredients of gunpowder as
follows : — Nitro-naphthalene, 10 parts ; saltpetre, 75 parts ;
charcoal, 12.5 parts; and sulphur, 12.5 parts. He states
that he obtains a mono-nitro-naphthalene, containing a
small proportion of di-nitro-naphthalene, by digesting I part
of naphthalene, with or without heat, in 4 parts of nitric acid
(specific gravity 1.40) for five days.
Quite lately a patent has been taken out for a mixture
of nitro-naphthalene or di-nitro-benzene with ammonium
nitrate, and consists in using a solvent for one or other or
both of the ingredients, effected in a wet state, and then
evaporating off the solvent, care being taken not to melt
the hydrocarbon. In this way a more intimate mixture is
ensured between the particles of the components, and the
explosive thus prepared can be fired by a small detonator,
viz., by 0.54 grms. of fulminate. Favier's explosive also
contains mono-nitro-naphthalene (8.5 parts), together with
91.5 parts of nitrate of ammonia. This explosive is
made in England by the Miners' Safety Explosive Co.
A variety of roburite contains chloro-nitro-naphthalene.
Romit consists of 100 parts ammonium nitrate and 7 parts
AMMONITE. 149
potassium chlorate mixed with a solution of I part nitro-
naphthalene and 2 parts rectified paraffin oil.
Ammonite. — This explosive was originally made at
Vilvorde in Belgium, under the title of the Favier Ex-
plosive, consisting of a compressed hollow cylinder com-
posed of 91.5 per cent, of nitrate of ammonia, and 8.5 per
cent, of mono-nitro-naphthaline filled inside with loose
powder of the same composition. The cartridges were
wrapped in paper saturated with paraffin-wax, and after-
wards dipped in hot paraffin to secure their being water-
tight. The Miners' Safety Explosives Co., when making
this explosive at their factory at Stanford-le-Hope, Essex,
abandoned after a short trial the above composition, and
substituted di-nitro-naphthalene 11.5 per cent, for the
mono-nitro-naphthalene, and used thin lead envelopes
filled with loose powder slightly pressed in, in place of the
compressed cylinders containing loose powder. The
process of manufacture is shortly as follows: — 132! Ibs.
of thoroughly dried nitrate of ammonium is placed in a
mill pan, heated at the bottom with live steam, and ground
for about twenty minutes until it becomes so dry that a
slight dust follows the rollers; then I/-J Ibs. of thoroughly
dry di-nitro-naphthalene is added, and the grinding con-
tinued for about ten minutes. Cold water is then circu-
lated through the bottom of the pan until the material
appears of a lightish colour and falls to powder. (While the
pan is hot the whole mass looks slightly plastic and of
a darker colour than when cold.) A slide in the bottom
of the pan is then withdrawn, the whole mass working out
until the pan is empty ; it is now removed to the sifting
machine, brushed through a wire sieve of about 12 holes
to the inch, and is then ready for filling into cartridges.
The hard core is returned from the sifting machine and
turned into one of the pans a few minutes before the
charge is withdrawn.
The ammonite is filled into the metallic cartridges by
150 NITRO-EXPLOSIVES.
means of an archimedian screw working through a brass
tube, pushing off the cartridges as the explosive is fed into
them against a slight back pressure ; a cover is screwed on,
and they then go to the dipping room, where they are
dipped in hot wax to seal the ends ; they are then packed
in boxes of 5 Ibs. each and are ready for delivery. The
di-nitro-naphthalene is made at the factory. Mono-nitro-
naphthalene is first made as follows: — 12 parts of com-
mercial nitrate of soda are ground to a fine powder, and
further ground with the addition of 15 parts of refined
naphthalene until thoroughly incorporated ; it is then placed
in an earthenware pan, and 30 parts of sulphuric acid of
66° B. added, 2 parts at a time, during forty-eight hours
(the rate of adding H2SO4 depends on the condition of
the charge, and keeping it in a fluid state), with frequent
agitation, day and night, during the first three or four days,
afterwards three or four times a day. In all fourteen
days are occupied in the nitration process. It is then
strained through an earthenware strainer, washed with
warm water, drained, and dried. For the purpose of pro-
ducing this material in a granulated condition, which is
found more convenient for drying, and further nitrification,
it is placed in a tub, and live steam passed through, until
brought up to the boiling point (the tub should be about
half full), cold water is then run in whilst violently agitat-
ing the contents until the naphthalene solidifies ; it can
then be easily drained and dried. For the further treat-
ment to make di-nitro-naphthalene, 18 parts of nitro-
naphthalene are placed in an earthenware pan, together
with 39 parts of sulphuric acid of 66° B., then 1 5 parts of
nitric acid of 40° B. are added, in small quantities at a
time, stirring the mixture continually. This adding of
nitric acid is controlled by the fuming, which should be
kept down as much as possible. The operation takes ten
to twelve days, when 100 times the above quantities, taken
in kilogrammes, are taken. At the end of the nitration
the di-nitro-naphthalene is removed to earthenware
ELECTRONITE AND SPRENGEL'S EXPLOSIVES. 151
strainers, allowed to drain, washed with hot water and
soda until all acid is removed, washed with water and
dried. The di-nitro-naphthalene gives some trouble in
washing, as some acid is held in the crystals which is liable
to make its appearance when crushed. To avoid this it
should be ground and washed with carbonate of soda
before drying ; an excess of carbonate of soda should not,
however, be used.
Electronite. — This is a high explosive designed to
afford safety in coal getting. This important end has
been attained by using such ingredients, and so propor-
tioning them, as will ensure on detonation a degree of
heat insufficient under the conditions of a " blown-out "
shot, to ignite fire damp or coal dust. It is of the nitrate
of ammonium class of permitted explosives. It contains
about 75 per cent, of nitrate of ammonium, with the addi-
tion of nitrate of barium, wood meal, and starch. The
gases resulting from detonation are chiefly water in the
gaseous form, nitrogen, and a little carbon dioxide. It is
granulated with the object of preventing missfires from
ramming, to which nitrate of ammonium explosives are
somewhat susceptible. This explosive underwent some
exhaustive experiments at the experimental station near
Wigan in 1895, when 8 oz. or 12 oz. charges were fired
unstemmed into an admixture of coal dust and 10 per
cent, of gas, without any ignition taking place. It is
manufactured by Messrs Curtis's & Harvey Ltd. at their
factory, Tonbridge, Kent.
Sprengel's Explosives. — This is a large class of ex-
plosives. The essential principle of them all is the admix-
ture of an oxidising with a combustible agent at the time
of, or just before, being required for use, the constituents
of the mixture being very often non-explosive bodies.
This type of explosive is due to the late Dr Herman
Sprengel, F.R.S. Following up the idea that an ex-
152 NITROEXPLOSIVES.
plosion is a sudden combustion, he submitted a variety
of mixtures of oxidising and combustible agents to the
violent shock of a detonator of fulminate. These mix-
tures were made in such proportions that the mutual
oxidation or de-oxidation should be theoretically complete.
Among them are the following : —
1. One chemical equivalent of nitro-benzene to 5
equivalents of nitric acid.
2. Five equivalents of picric acid to 13 equivalents of
nitric acid.
3. Eighty-seven equivalents of nitro-naphthalene to
413 equivalents of nitric acid.
4. Porous cakes, or lumps of chlorate of potash, ex-
ploded violently with bisulphide of carbon, nitro-benzol.
carbonic acid, sulphur, benzene, and mixtures of these
substances.
No. I covers the explosive known as Hellhoffite, and
No. 2 is really oxonite, and No. 4 resembles rack-a-rock,
an explosive invented by Mr S. R. Divine, and consisting
of a mixture of chlorate of potash and nitro-benzol.
Roburite, bellite, and securite should perhaps be regarded
as belonging to the Sprengel class of explosives, other-
wise this class is not manufactured or used in England.
The principal members are known as Hellhoffite, consist-
ing of a mixture of nitro-petroleum or nitro-tar oils and
nitric acid, or of meta-di-nitro-benzol and nitric acid ;
Oxonite^ consisting of picric and nitric acids ; and Pan-
clastite, a name given to various mixtures, proposed by M.
Turpin, such as liquid nitric peroxide, with bisulphide of
carbon, benzol, petroleum, ether, or mineral oils.
Picric Acid, Tri-nitro-Phenol, or Carbazotic Acid. —
Picric acid, or a tri-nitro-phenol (C6H2 (NO2)3OH) [2:4: 6],
is produced by the action of nitric acid on many organic
substances, such as phenol, indigo, wool, aniline, resins,
&c. At one time a yellow gum from Botany Bay {Xan-
thorrhcea has tilts) was chiefly used. One part of phenol
PICRIC ACID OR TRI-NITRO-PHENOL. 153
(carbolic acid), C6H5OH, is added to 3 parts of strong
fuming nitric acid, slightly warmed, and when the violence
of the reaction has subsided, boiled till nitrous fumes are
no longer evolved. The resinous mass thus produced is
boiled with water, the resulting picric acid is converted
into a sodium salt by a solution of sodium carbonate,
which throws down sodium picrate in crystals.
Phenol-sulphuric acid is now, however, more generally
used, and the apparatus employed for producing it closely
resembles that used in making nitro-benzol. It is also
made commercially by melting carbolic acid, and mixing
it with strong sulphuric acid, then diluting the " sulpho-
carbolic " * acid with water, and afterwards running it
slowly into a stone tank containing nitric acid. This is
allowed to cool, where the crude picric acid crystallises
out, and the acid liquid (which contains practically no
picric acid, but only sulphuric acid, with some nitric acid)
being poured down the drains. The crude picric acid is
then dissolved in water by the aid of steam, and allowed to
cool when most of the picric acid recrystallises. The
mother liquor is transferred to a tank and treated with sul-
phuric acid, when a further crop of picric acid crystals is
obtained. The crystals of picric acid are further purified
by recrystallisation, drained, and dried at 100° F. on glazed
earthenware trays by the aid of steam. It can also be
obtained by the action of nitric acid on ortho-nitro-phenol,
para-nitro-phenol, and di-nitro-phenol (2 : 4 and 2 : 6), but
not from meta-nitro-phenol, a fact which indicates its
constitution, j-
Picric acid crystallises in yellow shining prisms or
laminae having an intensely bitter taste, and is poisonous.
It melts at 122.5" C., sublimes when cautiously heated,
* O. and p. phenolsulphonic acids.
C6H4(OH).SO3H + 3HNO3= C6H2(NO2)3OH + H2SO4 + 2H,O.
(Picric acid).
t Carey Lea, Amer. Jour. Set. (ii.), xxxii. 180.
154 NITRO-EXPLOSIVES.
dissolves sparingly in cold water, more easily in hot water,
still more in alcohol. It stains the skin an intense yellow
colour, and is used as a dye for wool and silk. It is a
strong acid, forming well crystallised yellow salts, which
detonate violently when heated, some of them also by
percussion. The potassium salt, C6H2(NO2)3OK, crystal-
lises in long needles very slightly soluble in water. The
sodium, ammonium, and barium salts are, however, easily
soluble in water. Picric acid, when heated, burns with a
luminous and smoky flame, and may be burnt away in
large quantity without explosion ; but the mere contact
of certain metallic oxides, with picric acid, in the presence
of heat, develops powerful explosives, which are capable of
acting as detonators to an indefinite amount of the acid,
wet or dry, which is within reach of their detonative
influence. The formula of picric acid is (C6H., ;~TT )
V I OH. /
which shows its formation from phenol (C6H5OH.), three
hydrogen atoms being displaced by the NO2 group. The
equation of its formation from phenol is as follows : —
C6H5.OH + 3HN03-CGH2(N02)3OH + 3H20.
According to Berthelot, its heat of formation from its ele-
ments equals 49.1 calories, and its heat of total combustion
by free oxygen is equal to +618.4 cals. It hardly contains
more than half the oxygen necessary for its complete
combustion.'
The percentage composition of picric acid is — Nitrogen,
18.34; oxygen, 49.22 ; hydrogen, i.oo ; and carbon, 31.44,
equal to 60.26 per cent, of NO2. The products of decom-
position are carbonic acid, carbonic oxide, carbon, hydrogen,
and nitrogen, and the heat liberated, according to Berthelot,
would be 130.6 cals., or 570 cals. per kilogramme. The
reduced volume of the gases would be 190 litres per
equivalent, or 829 litres per kilogramme. To obtain a total
combustion of picric acid it is necessary to mix with it an
PROPERTIES OF PICRIC ACID. 155
oxidising agent, such as a nitrate, chlorate, &C.I It has
been proposed to mix picric acid (10 parts) wtEn sodium
nitrate (10 parts) and potassium bichromate (8.3 parts).
These proportions would furnish a third of oxygen in
excess of the necessary proportion.
Picric acid was not considered to be an explosive,
properly so called, for a long time after its discovery, but
the disastrous accident which occurred at Manchester (vide
Gov. Rep. No. LXXXI, by Colonel (now Sir V. D.)
Majendie, C.B.), and some experiments made by Dr Dupre
and Colonel Majendie to ascertain the cause of the accident,
conclusively proved that this view was wrong. The experi-
ments of Berthelot (Bull, de la Soc. Chim. de Paris, xlix.,
p. 456) on the explosive decomposition of picric acid are
also deserving of attention in this connection. If a small
quantity of picric acid be heated in a moderate fire, in a
crucible, or even in an open test tube, it will melt (at 120°
C. commercial acid), then give off vapours which catch fire
upon contact with air, and burn with a sooty flame, without
exploding. If the burning liquid be poured out upon a
cold slab, it will soon go out. A small quantity carefully
heated in a tube, closed at one end, can even be completely
volatilised without apparent decomposition. It is thus
obvious that picric acid is much less explosive than the
nitric ethers, such as nitro-glycerol and nitro-cellulose, and
very considerably less explosive than the nitrogen com-
pounds and fulminates.
It would, however, be quite erroneous to assume that
picric acid cannot explode when simply heated. On the
contrary, Berthelot has proved that this is not the case. If
a glass tube be heated to redness, and a minute quantity of
picric acid crystals be then thrown in, it will explode with
a curious characteristic, noise. If the quantity be increased
so that the temperature of the tube is materially reduced,
no explosion will take place at once, but the substance will
volatilise and then explode, though with much less violence
than before, in the upper part of the tube. Finally, if the
156 NITROEXPLOSIVES.
amount of picric acid be still further increased under these
conditions, it will undergo partial decomposition and volatil-
ise, but will not even deflagrate. Nitro-benzene, di-nitro-
benzene, and mono-, di-, and tri-nitro-naphthalenes behave
similarly.
The manner in which picric acid will decompose is thus
dependent upon the initial temperature of the decomposi-
tion, and if the surrounding material absorb heat as fast as
it is produced by the decomposition, there will be no
explosion and no deflagration. If, however, the absorption
is not sufficient to prevent deflagration, this may so increase
the temperature of the surrounding materials that the de-
flagration will then end in explosion. Thus, if an explosion
were started in an isolated spot, it would extend throughout
the mass, and give rise to a general explosion.
In the manufacture of picric acid the first obvious and
most necessary precaution is to isolate the substance from
other chemicals with which it might accidentally come into
contact. If pure materials only are used, the manufacture
presents no danger. The finished material, however, must
be carefully kept from contact with nitrates, chlorates, or
oxides. If only a little bit of lime or plaster become
accidentally mixed with it, it may become highly danger-
ous. A local explosion may occur which might have the
effect of causing the explosion of the whole mass. Picric
acid can be fired by a detonator, 5-grain fulminate, and
M. Turpin patented the use of picric acid, unmixed with
any other substance, in 1885. The detonation of a small
quantity of dry picric acid is sufficient to detonate a much
larger quantity containing as much as 17 per cent, of water.
It is chiefly due to French chemists (and to Dr Sprengel)
that picric acid has come to the front as an explosive.
Melinite,* a substance used by the French Government for
filling shells, was due to M. Turpin, and is supposed to be
* The British Lydite and the Japanese Shimose are said to be
identical with Melinite.
PICRIC POWDERS— MELINITE.
157
little else than fused picric acid mixed with gun-cotton
dissolved in some solvent (acetone or ether-alcohol). Sir
F. A. Abel has also proposed to use picric acid, mixed with
nitrate of potash (3 parts) and picrate of ammonia (2 parts)
as a filling for shells. This substance requires a violent blow
and strong confinement to explode it. I am not aware,
however, that it has ever been officially adopted in this
country. Messrs Designolles and Brugere have introduced
military powders, consisting of mixtures of potassium
and ammonium picrates with nitrate of potassium. M.
Designolles introduced three kinds of picrate powders,
composed as follows : —
For Torpedoes
and Shells.
For Guns.
Ordinary. Heavy.
For
Small Arms.
Picrate of Potash -
55-50
16.4- 9.6
9
28.6-22.9
Saltpetre
45-50
744-797
80
65.0-69.4
Charcoal
...
9.2-10.7
II
6.4- 77
They were made much like ordinary gunpowder, 6 to 14
per cent, of moisture being added when being milled. The
advantages claimed over gunpowder are greater strength,
and consequently greater ballistic or disruptive effect, com-
parative absence of smoke, and freedom from injurious
action on the bores of guns, owing to the absence of sulphur.
Brugere's powder is composed of ammonium picrate and
nitre, the proportions being 54 per cent, picrate of ammonia
and 46 per cent, potassic nitrate. It is stable, safe to
manfacture and handle, but expensive. It gives good
results in the Chassepot rifle, very little smoke, and its
residue is small, and consists of carbonate of potash. It is
stated that 2.6 grms. used in a rifle gave an effect equal to
5.5 grms. of ordinary gunpowder.
Turpin has patented various mixtures of picric acid,
158 NITRO-EXPLOSIVES.
with gum-arabic, oils, fats, collodion jelly, &c. When the
last-named substance is diluted in the proportion of from
3 to 5 per cent, in a mixture of ether and alcohol, he states
that the blocks of picric acid moulded with it will explode
in a closed chamber with a priming of from I to 3 grammes
of fulminate. He also casts picric acid into projectiles, the
cast acid having a density of about 1.6. In this state it
resists the shock produced by the firing of a cannon, when
contained in a projectile, having an initial velocity of 600
metres. It is made in the following way : — The acid is
fused in a vessel provided with a false bottom, heated to
130° to 145° C. by a current of steam under pressure, or
simply by the circulation under the false bottom of a liquid,
such as oil, chloride of zinc, glycerine, &c., heated to the
same temperature. The melted picric acid is run into
moulds of a form corresponding to that of the blocks
required, or it may be run into projectiles, which should
be heated to a temperature of about 100° C., in order to
prevent too rapid solidification.
When cresylic acid (or cresol, C6H4(CH3)OH.) is acted
upon by nitric acid it produces a series of nitro compounds
very similar to those formed by nitric acids on phenol, such
as sodium di-nitro-cresylate, known in the arts as victoria
yellow. Naphthol, a phenol-like body obtained from
naphthalene, under the same conditions, produces sodium
di-nitro-naphthalic acid, C10H6(NO2)2O. The explosive
known as " roburite " contains chloro-nitro-naphthalene, and
romit, a Swedish explosive, nitro-naphthalene.
Tri-nitro-cresol, C7H4(NO2)3OH.— A body very similar
to tri-nitro-phenol, crystallises in yellow needles, slightly
soluble in cold water, rather more so in boiling water,
alcohol, and ether. It melts at about 100° C. In France
it is known as " Cresilite," and mixed with melinite, is used
for charging shells. By neutralising a boiling saturated
solution of tri-nitro-cresol with ammonia, a double salt of
ammonium and nitro-cresol crystallises out upon cooling,
THE FULMINATES. 159
which is similar to ammonium picrate. This salt is known
as " Ecrasite," and has been used in Austria for charging
shells. It is a bright yellow solid, greasy to the touch,
melts at 100° C, is unaffected by moisture, heat, or cold,
ignites when brought into contact with an incandescent
body or open flame, burning harmlessly away unless
strongly confined, and is insensitive to friction or concussion.
It is claimed to possess double the strength of dynamite,
and requires a special detonator (not less than 2 grms. of
fulminate) to provoke its full force. Notwithstanding the
excellent properties attributed to this explosive, Lieut. W.
Walke ("Lectures on Explosives," p. 181) says, "Several
imperfectly explained and unexpected explosions have
occurred in loading shells with this substance, and have
prevented its general adoption up to the present time."
The Fulminates. — The fulminates are salts of fulminic
acid, C2N2O2H2. Their constitution is not very well under-
stood. Dr E. Divers, F.R.S., and Mr Kawakita {Chem. Soc.
Jour., 1884, pp. 13-19), give the formulae of mercury and
silver fulminates as
Hg
OC = N AgOC = N
O and
O
-C - N AgC - N
whereas Dr H. E. Armstrong, F.R.S., would prefer to write
the formula of fulminic acid ON.C.OH.
C(N.OH),
and A. F. Holleman (Berichte, v. xxvi., p. 1403), assigns to
mercury fulminate the formula C : N.O
Hg | |
C : N.O,
and R. Schol (Ber., v. xxiii., p. 3505), C : NO
II Hg.
C:NO
They are very generally regarded as iso-nitroso compounds.
l6o NITRO-EXPLOSIVES.
The principal compound of fulminic acid is the mercury
salt commonly known as fulminating mercury. It is pre-
pared by dissolving mercury in nitric acid, and then adding
alcohol to the solution, I part of mercury and 12 parts of
nitric acid of specific gravity 1.36, and 5| parts of 90 per
cent, alcohol being used. As soon as the mixture is in
violent reaction, 6 parts more of alcohol are added slowly
to moderate the action. At first the mixture blackens
from the separation of mercury, but this soon vanishes, and
is succeeded by crystalline flocks of mercury fulminate
which fall to the bottom of the vessel. During the reaction,
large quantities of volatile oxidation products of alcohol,
such as aldehyde, ethylic nitrate, &c., are evolved from the
boiling liquid, whilst others, such as glycollic acid, remain
in solution. The mercury fulminate is then crystallised
from hot water. It forms white silky, delicate needles,
which are with difficulty soluble in cold water. In the dry
state it is extremely explosive, detonating on heating, or
by friction or percussion, as also on contact with concen-
trated sulphuric acid. The reaction that takes place upon its
decomposition is as follows : —
C2N209Hg=Hg + 2CO + N9
(284)"
According to this equation I grm. of the fulminate should
yield 235.8 c.c. ( = 66.96 litres for 284 grms.). Berthelot
and Vieille have obtained a yield of 234.2 c.c., equal to 66.7
litres for one equivalent 284 grms.
/ Dry fulminate explodes violently when struck, com-
pressed, or touched with sulphuric acid, or as an incandescent
/body. If heated slowly, it explodes at 152° C, or if heated
rapidly, at 187° C. It is often used mixed with potas-
sium chlorate in detonators. The reaction which takes
place in this case is 3C9N2O2Hg + 2KClO3 = 3Hg + 6CO2
+ 3N2+2KC1.
On adding copper or zinc to a hot saturated solution
of the salt, fulminate of copper or zinc is formed. The
copper salt forms highly explosive green crystals. There
FULMINATES. l6l
is also a double fulminate of copper of ammonia, and of
copper and potassium. Silver fulminite, C2N2O2Ag2, is
prepared in a similar manner to the mercury salt. It
separates in fine white needles, which dissolve in 36 parts
of boiling water, and are with difficulty soluble in cold
water. At above 100° C., or on the weakest blow, it
explodes with fearful violence. Even when covered with
water it is more sensitive than the mercury salt. It forms
a very sensitive double salt with ammonia and several
other metals. With hydrogen it forms the acid fulminate
of silver. It is used in crackers and bon-bons, and other
toy fireworks, in minute quantities. Gay Lussac found it
to be composed as follows : — Carbon, 7.92 per cent. ; nitro-
gen, 9.24 per cent. ; silver, 72.19 per cent. ; oxygen, 10.65
per cent. ; and he assigned to it the formula, C2N2Ag2O2.
Laurent and Gerhardt give it the formula, C2N(NO2)Ag2,
and thus suppose it to contain nitryl, NO2.
On adding potassium chloride to a boiling solution of
argentic fulminate, as long as a precipitate of argentic
chloride forms, there is obtained on evaporation brilliant
white plates, of a very explosive nature, of potassic argentic
fulminate, C(NO2)KAg.CN, from whose aqueous solution
nitric acid precipitates a white powder of hydric argentic
fulminate, C(NO2)HAg.CN. All attempts to prepare
fulminic acid, or nitro-aceto-nitrile, C(NO2)H2CN, from
the fulminates have failed. There is a fulminate of gold,
which is a violently explosive buff precipitate, formed when
ammonia is added to ter-chloride of gold, and fulminate of
platinum, a black precipitate formed by the addition of
ammonia to a solution of oxide platinum, in dilute sulphuric
acid.
Fulminating silver is a compound obtained by the
action of ammonia on oxide of silver. It is a very violent
explosive. Pure mercury fulminate may be kept an in-
definite length of time. Water does not affect it. It ex-
plodes at 187° C., and on contact with an ignited body.
It is very sensitive to shock and friction, even that of wood
L
162 NITRO-EXPLOSIVES.
upon wood. It is used for discharging bullets in saloon
rifles. Its inflammation is so sudden that it scatters black
powder on which it is placed without igniting it, but it is
sufficient to place it in an envelope, however weak, for
ignition to take place, and the more resisting the envelope
the more violent is the shock, a circumstance that plays an
important part in caps and detonators. The presence of
30 per cent, of water prevents decomposition, 10 per cent,
prevents explosion. This is, however, only true for small
quantities, and does not apply to silver fulminate, which
explodes under water by friction. Moist fulminates slowly
decompose on contact with the oxidisable metals. The
(reduced) volume of gases obtained from I kilo, is according
to Berthelot, 235.6 litres. The equation of its decomposition
is C2HgN202 = 2CO + N2+Hg.
Fulminate of mercury is manufactured upon the large
scale by two methods. One of these, commonly known as
the German method, is conducted as follows : — One part of
mercury is dissolved in 12 parts of nitric acid of a specific
gravity of 1.375, and to this solution 16.5 parts of absolute
alcohol are added by degrees, and heat is then slowly
applied to the mixture until the dense fumes first formed
have disappeared, and when the action has become more
violent some more alcohol is added, equal in volume to
that which has already been added. This is added very
gradually. The product obtained, which is mercury ful-
minate, is 1 12 per cent, of the mercury employed. Another
method is to dissolve 10 parts of mercury in 100 parts of
nitric acid of a gravity of 1.4, and when the solution has
reached a temperature of 54° C., to pour it slowly through
a glass funnel into 83 parts of alcohol. When the efferves-
cence ceases, it is filtered through paper filters, washed, and
dried over hot water, at a temperature not exceeding 100°
C. The fulminate is then carefully packed in paper boxes,
or in corked bottles. The product obtained by this process
is 130 per cent, of the mercury taken. This process .is the
safest, and at the same time the cheapest. Fulminate
DETONATORS.
I63
should be kept, if possible, in a clamp state. Commercial
fulminate is often adulterated with chlorate of potash.
Detonators, or caps, are metallic capsules, usually of
copper, and resemble very long percussion caps. The ex-
plosive is pure fulminate of mercury, or a mixture of that
substance with nitrate or chlorate of potash, gun-powder,
or sulphur. The following is a common cap mixture : — 100
parts of fulminate of mercury and 50 parts of potassium
nitrate, or 100 parts of fulminate and 60 parts of meal
powder. Silver fulminate is also sometimes used in caps.
There are eight sizes made, which vary in dimensions
and in amount of explosive contained. They are further
distinguished as singles, doubles, trebles, &c., according to
their number. Colonel Cundill, R.A. (" Diet, of Explosives"),
gives the following list : —
No. i contains 300 grms. of explosive per 1000.
400
540
650
800
1,000
1,500
2,000
Trebles are generally used for ordinary dynamite, 5, 6, or 7
for gun-cotton, blasting gelatine, roburite, &c.
In the British service percussion caps, fuses, &c., are
formed of 6 parts by weight of fulminate of mercury, 6 of
chlorate of potash, and 4 of sulphide of antimony ; time
fuses of 4 parts of fulminate, 6 of potassium chlorate, 4 of
sulphide of antimony, the mixture being damped with a
varnish consisting of 645 grains of shellac dissolved in a
pint of methylated spirit. Abel's fuse (No. i) consists of a
mixture of sulphide of copper, phosphide of copper, chlorate
of potash, and No. 2 of a mixture of gun-cotton and gun-
powder. They are detonated by means of a platinum wire
heated to redness by means of an electric current. Bain's
164 NITRO-EXPLOSIVES.
fuse mixture is a mixture of subphosphidc of copper, sul-
phide of antimony, and chlorate of potash.
In the manufacture of percussion caps and detonators
the copper blanks are cut from copper strips and stamped
to the required shape. The blanks are then placed in a
gun-metal plate, with the concave side uppermost — a tool
composed of a plate of gun-metal, in which are inserted a
number of copper points, each of the same length, and so
spaced apart as to exactly fit each point into a cap when
inverted over a plate containing the blanks. The points
are dipped into a vessel containing the cap composition,
which has been previously moistened with methylated spirit.
It is then removed and placed over the blanks, and a slight
blow serves to deposit a small portion of the cap mixture
into each cap. A similar tool is then dipped into shellac
varnish, removed and placed over the caps, when a drop of
varnish from each of the copper points falls into the caps,
which are then allowed to dry. This is a very safe and
efficacious method of working.
At the works of the Cotton-Powder Company Limited,
at Faversham, the fulminate is mixed wet with a very finely
ground mixture of gun-cotton and chlorate of potash, in
about the proportions of 6 parts fulminate, I part gun-
cotton, and I part chlorate. The water in which the ful-
minate is usually stored is first drained off, and replaced by
displacement by methyl-alcohol. While the fulminate is
moist with alcohol, the gun-cotton and chlorate mixture
is added, and well mixed with it. This mixture is then
distributed in the detonators standing in a frame, and each
detonator is put separately into a machine for the purpose
of pressing the paste into the detonator shell.
At the eleventh annual meeting of the representatives
of the Bavarian chemical industries at Regensburg, atten-
tion was drawn to the unhealthy nature of the process of
charging percussion caps. Numerous miniature explosions
occur, and the air becomes laden with mercurial vappurs,
which exercise a deleterious influence upon the health of the
MANUFACTURE OF DETONATORS. 165
operatives. There is equally just cause for apprehension in
respect to the poisonous gases which are evolved during the
solution of mercury in nitric acid, and especially during the
subsequent treatment with alcohol. Many methods have
been proposed for dealing with the waste products arising
during the manufacture and manipulation of fulminate of
mercury, but according to Kaemmerer, only one of compara-
tively recent introduction appears to be at all satisfactory.
It is based upon the fact that mercuric fulminate, when
heated with a large volume of water under high pressure,
splits up into metallic mercury and non-explosive mercurial
compounds of unknown composition.
In mixing the various ingredients with mercury fulmin-
ate to form cap mixtures, they should not be too dry ; in
fact, they are generally more or less wet, and mixed in small
quantities at a time, in a special house, the floors of which
are covered with carpet, and the tables with felt. Felt shoes
are also worn by the workpeople employed. All the tools
and apparatus used must be kept very clean ; for granu-
lating, hair sieves are used, and the granulated mixture is
afterwards dried on light frames, with canvas trays the
bottoms of which are covered with thin paper, and the
frames fitted with indiarubber cushions, to reduce any jars
they may receive. The windows of the building should be
painted white to keep out the rays of the sun.
Mr H. Maxim, of New York, has lately patented a com-
position for detonators for use with high explosives, which
can also be thrown from ordnance in considerable quantities
with safety. The composition is prepared as follows : —
Nitro-glycerine is thickened with pyroxyline to the consist-
ency of raw rubber. This is done by employing about 75
to 85 per cent, of nitro-glycerine, and 15 to 25 per cent, of
pyroxyline, according to the stiffness or elasticity of the
compound desired. Some solvent that dissolves the nitro-
cotton is also used. The product thus formed is a kind of
blasting gelatine, and should be in a pasty condition, in
order that it may be mixed with fulminate of mercury. The
1 66
NITRO-EXPLOSIVES.
FIG. 34. — METHOD OF PRE-
PARING THE CHARGE.
solvent used is acetone, and the quantity of fulminate is
between 75 to 85 per cent, of the entire compound. If
desired, the compound can be made less sensitive to shocks
by giving it a spongy consistency by agitating it with air
while it is still in a syrupy condition.
The nitro-glycerine, especially in this
latter case, may be omitted. In some
cases, when it is desirable to add a
deterring medium, nitro-benzene or
some suitable gum is added.
The method of preparing a blast-
ing charge is as follows : — A piece of
Bickford fuse of the required length
is cut clean and is inserted into a
detonator until it reaches the ful-
minate. The upper portion of the
detonator is then squeezed round the
fuse with a pair of nippers. The
object of this is not only to secure
that the full power of the detonator may be developed,
but also to fix the fuse in the cap (Fig. 34). When the
detonator, &c., is to be used under water, or in a damp
situation, grease or tallow should be placed round the
junction of the cap with the fuse, in order
to make a water-tight joint. A cartridge
is then opened and a hole made in its
upper end, and the detonator pushed in
nearly up to the top. Gun-cotton or tonite
cartridges generally have a hole already
made in the end of the charge. Small
charges of dry gun-cotton, known as
primers, are generally used to explode wet
gun-cotton. The detonators (which are
often fired by electrical means) are placed inside these
primers (Fig. 35).
One of the forms of electric exploders used is shown
in Fig. 36. This apparatus is made by Messrs John Davis
FIG. 35.— PRI.MEK.
EXPLODERS.
I67
& Son, and is simply a small hand dynamo, capable of
producing a current of electricity of high tension. This
firm are also makers of various forms of low tension ex-
ploders. A charge having been prepared, as in Fig. 34,
insert into the bore-hole one or more cartridges as judged
necessary, and squeeze each one down separately with a
FIG. 36.— ELECTRIC EXPLODER.
wooden rammer, so as to leave no space round the charge,
and above this insert the cartridge containing the fuse and
detonator. Now fill up the rest of the bore-hole with sand,
gravel, water, or other tamping, With gelatine dynamites
a firm tamping may be used, but with ordinary dynamite
loose sand is better. The charge is now ready for firing.
CHAPTER VI.
SMOKELESS POWDERS.
Smokeless Powder in General — Cordite— Axite— Ballistite — U.S. Naval
Powder— Schultze's E.G. Powder — Indurite — Vielle Poudre — Rifleite —
Cannonite — Walsrode — Cooppal Powders — Amberite — Troisclorf —
Maximite — Picric Acid Powders, &c. , &c.
THE progress made in recent years in the manufacture of
smokeless powders has been very great. With a few ex-
ceptions, nearly all these powders are nitro compounds,
and chiefly consist of some form of nitro-cellulose, either
in the form of nitro-cotton or nitro-lignine ; or else contain,
in addition to the above, nitre-glycerine, with very often
some such substance as camphor, which is used to reduce
the sensitiveness of the explosive. Other nitro bodies that
are used, or have been proposed, are nitro-starch, nitro-jute,
nitrated paper, nitro-benzene, di-nitro-benzene, mixed with
a large number of other chemical substances, such as nitrates,
chlorates, &c. And lastly, there are the picrate powders,
consisting of picric acid, either alone or mixed with other
substances.
The various smokeless powders may be roughly divided
into military and sporting powders. But this classification
is very rough ; because although some of the better known
purely military powders are not suited for use in sporting
guns, nearly all the manufacturers of sporting powders also
manufacture a special variety of their particular explosive,
fitted for use in modern rifles or machine guns, and
occasionally, it is claimed, for big guns also.
Of the purely military powders, the best known are
cordite, ballistite, and the French B.N. powder, the German
smokeless (which contains nitro-glycerine and nitro-cottbn);
CORDITE. 169
and among the general powders, two varieties of which are
manufactured either for rifles or sporting guns, Schultze's,
the E.G. Powders, Walsrode powder, cannonite, Cooppal
powder, amberite, &c., &c.
Cordite, the smokeless powder adopted by the British
Government, is the patent of the late Sir F. A. Abel and
Sir James Dewar, and is somewhat similar to blasting
gelatine. It is chiefly manufactured at the Royal Gun-
powder Factory at Waltham Abbey, but also at two or
three private factories, including those of the National
Explosives Company Limited, the New Explosives Com-
pany Limited, the Cotton-Powder Company Limited, Messrs
Kynock's, &c. As first manufactured it consisted of gun-
cotton 37 per cent., nitro-glycerine 58 per cent., and vaseline
5 per cent., but the modified cordite now made consists of
65 per cent, gun-cotton, 30 per cent, of nitro-glycerine, and
5 per cent, of vaseline. The gun-cotton used is composed
chiefly of the hexa-nitrate,* which is not soluble in nitro-
glycerine. It is therefore necessary to use some solvent
such as acetone, in order to form the jelly with nitro-glycerine.
The process of manufacture of cordite is very similar, as
far as the chemical part of the process is concerned, to that
of blasting gelatine, with the exception that some solvent
for the gun-cotton, other than nitro-glycerine has to be used.
Both the nitro-glycerine and the gun-cotton employed
must be as dry as possible, and the latter should not contain
more than .6 per cent, of mineral matter and not more
than 10 per cent, of soluble nitro-cellulose, and a nitrogen
content of not less than 12.5 per cent. The dry gun-cotton
(about I per cent, of moisture) is placed in an incorporating
tank, which consists of a brass-lined box, some of the acetone
is added, and the machine (Fig. 29), is started ; after some
time the rest of the acetone is added (20 per cent, in all)
* The gun-cotton used contains 12 per cent, of soluble gun-cotton,
and a nitrogen content of not less than 12.8 to 13.1 per cent.
I/O NITRO-EXPLOSIVES.
and the paste kneaded for three and a half hours. At the
end of this time the vaselene is added, and the kneading
continued for a further three and a half hours. The knead-
ing machine (Fig. 29) consists of a trough, composed of
two halves of a cylinder, in each of which is a shaft which
carries a revolving blade. These blades revolve in opposite
directions, and one makes about half the number of revolu-
tions of the other. As the blades very nearly touch the
bottom of the trough, any material brought into the machine
is divided into two parts, kneaded against the bottom, then
pushed along the blade, turned over, and completely mixed.
During kneading the acetone gradually penetrates the
mixture, and dissolves both the nitro-cellulose and nitro-
glycerine, and a uniform dough is obtained which gradually
assumes a buff colour. During kneading the mass becomes
heated, and therefore cold water is passed through the
jacket of the machine to prevent heating the mixture above
the normal temperature, and consequent evaporation of the
acetone. The top of the machine is closed in with a glass
door, in order to prevent as far as possible the evaporation
of the solvent. When the various ingredients are formed
into a homogeneous mass, the mixture is taken to the press
house, where in the form of a plastic mass it is placed in
cylindrical moulds. The mould is inserted in a specially
designed press, and the cordite paste forced through a die
with one or more holes. The paste is pressed out by
hydraulic pressure, and the long cord is wound on a metal
drum (Fig. 38), or cut into lengths ; in either case the cordite
is now sent to the drying houses, and dried at a temperature
of about 100° F. from three to fourteen days, the time
varying with the size. This operation drives off the acetone,
and any moisture the cordite may still contain, and its
diameter decreases somewhat. In case of the finer cordite,
such as the rifle cordite, the next operation is blending.
This process consists in mounting ten of the metal drums
on a reeling machine similar to those used for yarns, and
winding the ten cords on to one drum. This operation is
MANUFACTURE OF CORDITE.
171
known as " ten-stranding." Furthermore, six "ten-stranded "
reels are afterwards wound upon one, and the " sixty-
stranded " reel is then ready to be sent away. This is
done in order to obtain a uni-
form blending of the material.
With cordite of a larger dia-
meter, the cord is cut into
lengths of 12 inches. Every
lot of cordite from each manu-
facturer has a consecutive num-
ber, numbers representing the
size and one or more initial
letters to identify the manu-
facturer. These regulations do not apply to the Royal
Gunpowder Factory, Waltham Abbey. The finished cordite
resembles a cord of gutta-percha, and its colour varies from
Scale, I mch=l foot.
Single Strand Reel.
FIG. 38. — "TEN-STRANDING."
light to dark brown. It should not look black or shrivelled,
and should always possess sufficient elasticity to return to
its original form after slight bending. Cordite is practically
NITRO-EXPLOSIVES.
smokeless. On explosion a very thin vapour is produced,
which is dissipated rapidly. This smokelessness can be
understood from the fact that the products of combustion
are nearly all non-condensible gases, and contain no solid
products of combustion which would cause smoke. For
the same muzzle velocity a smaller charge of cordite than
gunpowder is required owing to the greater amount of gas
produced. Cordite is very slow in burning compared to
gunpowder. For firing blank cartridges cordite chips con-
taining no vaselene is used. The rate at which cordite
explodes depends in a measure upon the diameter of the
cords, and the pressure developed upon its mechanical
state. The sizes of cordite used are given by Colonel
Barker, R.A., as follows : —
For the .303 rifle - -°375 inch diameter.
12 Pr. B.L. gun .05 „
» 35 " '°75 "
4.7-inch Q.F. gun .100 „
6-inch Q.F. gun .300 „
heavy guns - .40 to .50 ,,
For rifles the cordite is used in bundles of sixty strands,
in field-guns in lengths of 1 1 to 12 inches, and the thicker
cordite is cut up into 1 4-inch lengths. Colonel Barker says
that the effect of heat upon cordite is not greater as regards
its shooting qualities than upon black powder, and in
speaking of the effect that cordite has upon the guns in
which it is used (R.A. Inst.) said that they had at Waltham
Abbey a 4.7-inch Q.F. gun that had fired 40 rounds of
black powder, and 249 rounds of cordite (58 per cent,
nitro-glycerine) and was still in excellent condition, and
showed very little sign of action, and also a 12-lb. B.L. gun
that had been much used and was in no wise injured.
In some experiments made by Captain Sir A. Noble,*
with the old cordite containing 58 per cent, nitro-glycerine,
a charge of 5 Ibs. 10 oz. of cordite of 0.2 inch diameter
* Proc. Roy, Soc., vol. lii., No. 315.
PROPERTIES OF CORDITE. 1/3
was fired. The mean chamber crusher gauge pressure was
13.3 tons per square inch (maximum 13.6, minimum 12.9),
or a mean of 2,027 atmospheres (max. 2,070, min. 1,970).
The muzzle velocity was 2,146 foot seconds, and the muzzle
energy ,1,437 foot tons. A gramme of cordite generated
700 c.c. of permanent gases at o° C. and 760 mm. pressure.
The quantity of heat developed was 1,260 gramme units.
In the case of cordite, as also with ballistite, a considerable
quantity of aqueous vapour has to be added to the per-
manent gases formed. A similar trial, in which 12 Ibs. of
ordinary pebble powder was used, gave a pressure of 15.9
tons per square inch, or a mean of 2,424 atmospheres. It
gave a 45 -Ib. projectile a mean muzzle velocity of 1,839 f°ot
seconds, thus developing a muzzle energy of 1,055 f°ot tons.
A gramme of this powder at o° C. and 760 mm. generates
280 c.c. of permanent gases, and develops 720 grm. units
of heat.
In a series of experiments conducted by the War Office
Chemical Committee on Explosives in 1891, it was con-
clusively shown that considerable quantities of cordite may
be burnt away without explosion. A number of wooden
cases, containing 500 to 600 Ibs. each of cordite, were placed
upon a large bonfire of wood, and burned for over a quarter
of an hour without explosion. At Woolwich in 1892 a
brown paper packet containing ten cordite cartridges was
fired into with a rifle (.303) loaded with cordite, without the
explosion of a single one of them, which shows its insensi-
bility to shock.
With respect to the action of cordite upon guns, Sir A.
Noble points out that the erosion caused is of a totally
different kind to that of black powder. The surface of the
barrel in the case of cordite appears to be washed away
smoothly by the gases, and not pitted and eaten into as
with black powder. The erosion also extends over a
shorter length of surface, and in small arms it is said to be
no greater than in the case of black powder. Sir A. Noble
says in this connection : " It is almost unnecessary to explain
174
NITRO-EXPLOSIVES.
that freedom from rapid erosion is of very high importance
in view of the rapid deterioration of the bores of large guns
when fired with charges developing very high energies.
As might perhaps be anticipated from the higher heat of
ballistite, its erosive power is slightly greater than that of
cordite, while the erosive power of cordite is again slightly
greater than that of brown prismatic. Amide powder, on
the other hand, possesses the peculiarity of eroding very
much less than any other powder with which I have ex-
perimented, its erosive power being only one-fourth of that
of the other powders enumerated."
TABLE GIVING SOME OF SIR A. NOBLE'S
EXPERIMENTS.
VELOCITIES OBTAINED.
In a 40
In a 50
In a 75
In a 100
Cal. Gun.
Cal. Gun.
Cal. Gun.
Cal. Gun.
Foot Sees.
Foot Sees.
Foot Sees.
Foot Sees.
With cordite 0.4 in. diam. -
2,794
2,940
3, 1 66
3,286
„ » °-3 »
2,469
2,6l9
2,811
2,905
„ ballistite 0.3 in. cubes
2,4l6
2,537
2,713
2,806
„ French B.N. for)
6-inch guns - - J
2,249
2,360
2,536
2,616
„ prismatic amide
2,2l8
2,342
2,511
2,574
ENERGIES REPRESENTED BY ABOVE VELOCITIES.
Foot Tons.
Foot Tons.
Foot Tons. Foot Tons.
Cordite 0.4 inch
5,4i3 5,994 6,950 7,478
Ballistite 0.3 inch cubes - ; 4,227 , 4,754 j 5,479 5,852
French B.N.
4,047
4,463
5,104 5,460
Prismatic amide
3,507
3,862
4.460 4,745
And again, in speaking of his own experiments, he says :
"One 4.7-inch gun has fired 1,219 rounds, and another 953,
all with full charges of cordite, while a 6-inch gun has fired
PROPERTIES OF CORDITE.
175
34
Q O
It
Q
588 rounds with full charges, of which 355 were cordite.
In the whole of these guns, so far as I can judge, the erosion
is certainly not greater than with ordinary powder, and
differs from it remarkably in
appearance. With ordinary
powder a gun, when much
eroded, is deeply furrowed (these
furrows having a great tendency
to develop into cracks), and
presents much the appearance
in miniature of a very roughly
ploughed field. With cordite,
on the contrary, the surface
appears to be pretty smoothly
swept away, while the length of
the surface eroded is consider-
ably less."
The pressures given by cor-
dite compared with those given
by black powder in the 6-inch
gun will be seen upon reference
to Fig. 39, which is taken from
Professor V. B. Lewes's paper,
read before the Society of Arts ;
and due to Dr W. Anderson,
F.R.S., the Director-General of
Ordnance Factories.
It has been found that the
erosive effect is in direct pro-
portion to the nitro-glycerine
present. The cordite M.D.,
which contains only 30 per cent,
nitro-glycerine, gives only about
half the erosive effect of the old
service cordite. With regard to
the heating effect of cordite and
cordite M.D. on a rifle, Mr T. W.
176 NITRO-EXPLOSIVES.
Jones made some experiments. He fired fifty rounds of
.303 cartridges in fifteen minutes in the service rifle. Cor-
dite raised the temperature of the rifle 270° F., and cordite
M.D. 1 60° F. only.
With regard to the effect of heat upon cordite, there is
some difference of opinion. Dr W. Anderson, F.R.S., says
that there is no doubt that the effect of heat upon cordite
is greater than upon black powder. At a temperature of
1 10° F. the cordite used in the 4.7-inch gun is considerably
affected as regards pressure.
Colonel Barker, R.A., in reply to a question raised by
Colonel Trench, R.A. (at the Royal Artillery Institution),
concerning the shooting qualities of cordite heated to a
temperature of 110° F., said: "Heating cordite and firing
it hot undoubtedly does disturb its shooting qualities, but
as far as we can see, not much more than gunpowder. I
fear that we must always expect abnormal results with
heated propel lants, either gunpowder or cordite ; and when
fired hot, the increase in pressure and velocities will depend
upon the heat above the normal or average temperature
at which firing takes place." Colonel Barker also, in
referring to experiments that had been made in foreign
climates, said : " Climatic trials have been carried out all
over the world, and they have so far proved eminently
satisfactory. The Arctic cold of the winter in Canada,
with the temperature below zero, and the tropical sun of
India, have as yet failed to shake the stability of the
composition, or abnormally injure its shooting qualities."
Dr Anderson is of opinion that cordite should not be
stored in naval magazines near to the boilers. Professor
Vivian B. Lewes, in his recent Cantor Lectures before the
Society of Arts, suggests that the magazines of warships
should be water-jacketed, and maintained at a temperature
that does not rise above 100° F.
Axite. — This powder is manufactured by Messrs Kynock
Limited, at their works at Witton, Birmingham. The main
AXITE. 177
constituents of cordite are retained although the proportions
are altered ; ingredients are added which impart properties
not possessed by cordite, and the methods of its manu-
facture have been modified. The form has also been
altered. Axite is made in the form of a ribbon, the cross
section being similar in shape to a double-headed rail. It
is claimed for this powder, that it does not corrode the barrel
in the way cordite does, that with equal pressure it gives
greatly increased velocity, and therefore flatter trajectory.
That the effect of temperature on the pressure and velocity
with axite is only half that with cordite. That the maxi-
mum flame temperature of axite is considerably less than
that of cordite, and the erosive effect is therefore consider-
ably less. That the deposit left in the barrel after firing
axite cartridges reduces the friction between the bullet and
the barrel. It is therefore practicable to use axite cartridges
giving higher velocities than can be employed with cordite,
as with such velocities the latter would nickel the barrel by
excessive friction. It is also claimed that the accuracy is
greatly increased. The following results have been obtained
with this powder, when fired from a service .303 rifle,
cordite being fired at the same time, and under the same
conditions : —
Axite Cartridges with 200 grain bullets.
Velocity - - 2,726 F.S.
Pressure 20.95 tons.
Axite Cartridges with 2i5-grain bullets.
Velocity - 2,498 F.S.
Pressure 19.24 tons.
Axite Service Cartridges.
Velocity - 2,179 F.S.
Pressure - 15. 76 tons.
Cordite Service Cartridges.
Velocity - - 2,010 F.S.
Pressure - - 15.67 tons.
Five rounds from the Service axite and Service cordite
were placed in an oven and heated to a temperature of
M
NlTRO-EXt>LOSlVES.
1 10° F. for one hour, and were then fired for pressure. The
following results were obtained : —
Axite. Cordite.
Before heating - - 15.76 tons per sq. in. 15-67 tons per sq. in.
After ,, - - 16.73 » 17-21
Increase - - .97-6.1% i.S4 = 9-80/0
Average Velocities —
Before heating - - 2,i5oF.S. 2,030 F.S.
After ,, - - 2,180 ,, 2,090 ,,
Increase - - 30 F.S. = i£ °/0 60.0 F.S. -3 %
In order to show the accuracy given by axite, seven
rounds were fired from a machine rest at a target fixed at
100 yards from a rifle. Six of the seven shots could be
covered by a penny piece, the other being just outside. In
order to ascertain the relative heat imparted to a rifle by
the explosion of axite and cordite, ten rounds each of axite
and cordite cartridges were fired from a .303 rifle, at intervals
of ten seconds, the temperature of the rifle barrel being
taken before and after each series : —
THE RISE IN TEMPERATURE OF THE RIFLE BARREL
With axite was - - - 71° F.
With cordite was - - - 89° F.
Difference in favour of axite - 18° F. —20.2 °fc.
The lubricating action of axite is shown by the fact that
a series of cordite cartridges fired from a .303 rifle in the
ordinary way, followed by a second series, the barrel being
lubricated between each shot by firing an axite cartridge
alternately with the cordite cartridge. The mean velocity
of the first series of cordite cartridges was 1,974 ft. per
second ; the mean velocity of the second series was 2,071 ft.
per second ; the increased velocity due to the lubricating
effect of axite therefore was 97 ft. per second. This powder,
it is evident, has very many very excellent qualities, and
considerable advantages over cordite. It is understood that
axite is at present under the consideration of the British
Government for use as the Service powder.
BALLISTITE. 179
Ballistite. — Nobel's powder, known as ballistite, origin-
ally consisted of a camphorated blasting gelatine, and was
made of 10 parts of camphor in 100 parts of nitro-glycerine,
to which 200 parts of benzol were then added, and 50 parts
of nitro-cotton (soluble) were then steeped in this mixture,
which was then heated to evaporate off the benzol, and the
resulting compound afterwards passed between steam-heated
rollers, and formed into sheets, which were then finally cut
up into small squares or other shapes as convenient. The
camphor contained in this substance was, however, found
to be a disadvantage, and its use discontinued. The com-
position is now 50 per cent, of soluble nitro-cotton and 50
per cent, of nitro-glycerine. As nitro-glycerine will not
dissolve its own weight of nitro-cotton (even the soluble
variety), benzol is used as a solvent, but is afterwards
removed from the finished product, just as the acetone is
removed from cordite. About I per cent, of diphenylamine
is added for the purpose of increasing its stability.
The colour of ballistite is a darkish brown. It burns in
layers when ignited, and emits sparks. The size of the
cubes into which it is cut is a o.2-inch cube. Its density is
1.6. It is also, by means of a special machine, prepared in
the form of sheets, after being mixed in a wooden trough
fitted with double zinc plates, and subjected to the heating
process by means of hot-water pipes. It is passed between
hot rollers, and rolled into sheets, which are afterwards put
through a cutting machine and granulated. Sir A. Nobel's
experiments* with this powder gave the following results : —
The charge used was 5 Ibs. 8 oz., the size of the cubes being
0.2 inch. The mean crusher-gauge pressure was 14.3 tons
per square inch (maximum, 2,210; minimum, 2,142), and
average pressure 2,180 atmospheres. The muzzle velocity
was 2,140 foot seconds, and the muzzle energy 1,429 foot
tons. A gramme of ballistite generates 615 c.c. of per-
manent gases, and gives rise to 1,365 grm. units of heat.
Proc. Roy. Soc.* vol. lii., p. 315.
l8o NITRO-EXPLOSIVES.
Ballistite is manufactured at Ardeer in Scotland, at Chil-
worth in Surrey, and also in Italy, under the name of
Filite, which is in the form of cords instead of cubes. The
ballistite made in Germany contained more nitro-cellulose,
and the finished powder was coated with graphite. Its use
has been discontinued as the Service powder in Germany,
but it is still the Service powder in Italy.
U.S. Naval Smokeless Powder. — This powder is
manufactured at the U.S. Naval Torpedo Station for use in
guns of all calibres in the U.S. Navy. It is a nitro-cellulose
powder, a mixture of insoluble and soluble nitro-cellulose
together with the nitrates of barium and potassium, and a
small percentage of calcium carbonate. The proportions in
the case of the powder for the 6-inch rapid-fire gun are as
follows: — Mixed nitro-cellulose (soluble and insoluble) 80
parts, barium nitrate 1 5 parts, potassium nitrate 4 parts, and
calcium carbonate I part. The percentage of nitrogen con-
tained in the insoluble nitro-cellulose must be 13. 30 ±0.15,
and in the soluble Ii.6o±o.i5, and the mean nitration
strength of the mixture must be 12.75 per cent, of nitrogen.
The solvent used in making the powder is a mixture of
ether (sp. gr. 0.720) 2 parts, and alcohol (95 per cent, by
volume) i part. The process of manufacture is briefly as
follows :* — The soluble and insoluble nitro-cellulose are
dried separately at a temperature from 38° to 41° C, until
they do not contain more than o.i per cent, of moisture.
The calcium carbonate is also finely pulverised and dried,
and is added to the mixed nitro-celluloses after they have
been sifted through a i6-mesh sieve. The nitrates are next
weighed out and dissolved in hot water, and to this solution
is added the mixture of nitro-celluloses and calcium carbon-
ate with constant stirring until the entire mass becomes a
homogeneous paste. This pasty mass is next spread upon
trays and re-dried at a temperature between 38° and 48° C.,
* Lieut. W. Walke, " Lectures on Explosives," p. 330.
U.S. NAVAL POWDER. iSf
and when thoroughly dry it is transferred to the kneading
machine. The ether-alcohol mixture is now added, and the
process of kneading begun. It has been found by experi-
ment that the amount of solvent required to secure thorough
incorporation is about 500 c.c. to each 500 grms. of dried
paste. To prevent loss of solvent due to evaporation, the
kneading machine is made vapour light. The mixing or
kneading is continued until the resulting greyish-yellow
paste is absolutely homogeneous so far as can be detected
by the eye, which requires from three to four hours. The
paste is next treated in a preliminary press (known as the
block press and is actuated by hydraulic power), where it is
pressed into a cylindrical mass of uniform density and of
such dimensions as to fit it for the final or powder press.
The cylindrical masses from the block press are transferred
to the final press, whence they are forced out of a die under
a pressure of about 500 Ibs. per square inch. As it emerges
from the final press the powder is in the form of a ribbon
or sheet, the width and thickness of which is determined by
the dimensions of the powder chamber of the gun in which
the powder is to be used. On the inner surface of the die
are ribs extending in the direction of the powder as it
emerges from the press, the object of these ribs being to
score the sheets or ribbons in the direction of their length,
so that the powder will yield uniformly to the pressure of
the gases generated in the gun during the combustion of
the charge. The ribbon or sheet is next cut into pieces
of a width and length corresponding to the chamber of the
gun for which it is intended, the general rule being that the
thickness of the grain (when perfectly dry) shall be fifteen
one-thousandths (.015) of the calibre of the gun, and the
length equal to the length to fit the powder chamber.
Thus, in case of the 6-inch rapid-fire gun the thickness of
the grain (or sheet) is 0.09 of an inch and the length
32 inches. The sheets are next thoroughly dried, first
between sheets of porous blotting-paper under moderate
pressure and at a temperature between 15° C. and 21.5° C.
1 82 NITRO-EXPLOSIVES.
for three days, and then exposed to free circulation of the
air at about 21.5° C. for seven clays, and finally subjected
for a week or longer to a temperature not exceeding 38° C.
until they cease to lose weight.
The sheets, when thoroughly dried, are of a uniform
yellowish-grey colour, and of the characteristic colloidal
consistency ; they possess a perfectly smooth surface, and
are free from internal blisters or cracks. The temperature
of ignition of the finished powder should not be below
172° C., and when subjected to the heat or stability test, it
is required to resist exposure to a temperature of 71° C. for
thirty minutes without causing discoloration of the test
paper.
W.A. Powder. — This powder is made by the American
Smokeless Powder Company, and it was proposed for use in
the United States Army and Navy. It is made in several
grades according to the ballistic conditions required. It
consists of insoluble gun-cotton and nitre-glycerine, together
with metallic nitrates and an organic substance used as a
deterrent or regulator. The details of its manufacture are
very similar to those of cordite, with the exception that the
nitro-glycerine is dissolved in a portion of the acetone,
before it is added to the gun-cotton. The powder is pressed
into solid threads, or tubular cords or cylinders, according
to the calibre of the gun in which the powder is to be used.
As the threads emerge from the press they are received
upon a canvas belt, which passes over steam-heated pipes,
and deposited in wire baskets. The larger cords or cylinders
are cut into the proper lengths and exposed upon trays irt
the drying-house. The powder for small arms is granulated
by cutting the threads into short cylinders, which are subse-
quently tumbled, dusted, and, if not perfectly dry, again
placed upon trays in the drying-house. Before being sent
away from the factory, from five to ten lots of 500 Ibs. each
are mixed in a blending machine, in order to obtain greater
uniformity. The colour of the W.A. powder is very light
SCHULTZE POWDER. 183
grey, the grains are very uniform in size, dry and hard. The
powder for larger guns is of a yellowish colour, almost
translucent, and almost as hard as vulcanite. The powder
is said to be unaffected by atmospheric or climatic conditions,
to be stable, and to have given excellent ballistic results ; it
is not sensitive to the impact of bullets, and when ignited
burns quietly, unless strongly confined.
Turning now to the smokeless powders, in which the
chief ingredient is nitro-cellulose in some form (either gun-
cotton or nitro-lignine, &c.), one of the first of these was
Prentice's gun-cotton, which consisted of nitrated paper
15 parts, mixed with 85 parts of unconverted cellulose. It
was rolled into a cylinder. Another was Punshon's gun-
cotton powder, which consisted of gun-cotton soaked in a
solution of sugar, and then mixed with a nitrate, such as
sodium or potassium nitrate. Barium nitrate was after-
wards used, and the material was granulated, and consisted
of nitrated gun-cotton.
The explosive known as tonite, made at Faversham,
was at first intended for use as a gunpowder, but is now
only used for blasting.
The Schultze Powder. — One of the earliest of the suc-
cessful powders introduced into this country was Schultze's
powder, the invention of Colonel Schultze, of the Prussian
Artillery, and is now manufactured by the Schultze Gun-
powder Company Limited, of London. The composition
of this powder, as given in the " Dictionary of Explosives "
by the late Colonel Cundall, is as follows : —
Soluble nitro-lignine - 14-83 per cent.
Insoluble „ - 23.36 „
Lignine (unconverted) - - - 13.14 „
Nitrates of K and Ba - - - - 32.35 „
Paraffin .--.-. 3.65 „
Matters soluble in alcohol - - - o. 1 1 „
Moisture ------ 2.56 „
This powder was the first to solve the difficulty of
184 NITRO-EXPLOSIVES.
making a smokeless, or nearly smokeless powder which
could be used with safety and success in small arms.
Previously, gun-cotton had been tried in various forms,
and in nearly every instance disaster to the weapon had
followed, owing to the difficulty of taming the combustion
to a safe degree. But about 1866 Colonel Schultze pro-
duced, as the result of experiments, a nitrated wood fibre
which gave great promise of being more pliable and more
easily regulated in its burning than gun-cotton, and this
was at once introduced into England, and the Schultze
Gunpowder Company Limited was formed to commence
its manufacture, which it did in the year 1868. During the
years from its first appearance, Schultze gunpowder has
passed through various modifications. It was first made in
a small cubical grain formed by cutting the actual fibre of
timber transversely, and then breaking this veneer into
cubes. Later on improvements were introduced, and the
wood fibre so produced was crushed to a fine degree, and
then reformed into small irregular grains. Again, an ad-
vance was made in the form of the wood fibre used, the
fibre being broken down by the action of chemicals under
high temperature, and so producing an extremely pure
form of woody fibre. The next improvement was to render
the grains of the powder practically waterproof and less
affected by the atmospheric influences of moisture and
dryness, and the last improvement to the process was that
of hardening the grains by means of a solvent of nitro-
lignine, so as to do away with the dust that was often
formed from the rubbing of the grains during transit.
Minor modifications have from time to time also been
made, in order to meet the gradual alteration which has
taken place during this long period in .the manufacture of
sporting guns and cartridge cases to be used with this
powder, but through all its evolution this Company has
adhered to the first idea of using woody fibre in preference
to cotton as the basis of their smokeless powder, as experi-
ence has confirmed the original opinion that a powder can
SCHULTZE POWDER. 185
be thus made less sensitive to occasional differences in
loading, and more satisfactory all round than when made
from the cotton base. The powder has always been regu-
lated so that bulk for bulk it occupies the same measure as
the best black powder, and as regards its weight, just one
half of that of black.
The process of manufacture of this powder is briefly as
follows :—
Wood of clean growth is treated by the well-known
sulphite process for producing pure woody fibre, which is
very carefully purified, and this, after drying, is steeped in a
mixture of nitric and sulphuric acids, to render it a nitro-
compound and the explosive base of the powder. This
nitro compound is carefully purified until it stands the very
high purity requirements of the Home Office, and is then
ground with oxygen- bearing salts, &c., and the whole is
formed into little irregular-shaped grains of the desired
size, which grains are dried and hardened by steeping in a
suitable solvent for the nitro compound, and after finally
drying, sifting, &c., the powder is stored in magazines for
several months before it is issued. When issued, a very
large blend is made of many tons weight, which ensures
absolute uniformity in the material.
There is in England a standard load adopted by every
one for testing a sporting powder ; this charge is 42 grains
of powder and ij oz. No. 6 shot — this shot fired from a
12-bore gun, patterns being taken at 40 yards, the velocity
at any required distance.
The standard muzzle velocity of Schultze gunpowder is
1,220 feet per second.
The mean 40 yards ditto is 875 feet per second.
The mean 20 yards ditto is 1,050 feet per second.
The internal pressure not to exceed 3.5 tons.
This Company also manufactures a new form of powder,
known as Imperial Schultze. It is a powder somewhat
lighter in gravity ; 33 grains occupies the bulk charge, as
compared with the 42 grains of the old. It follows in its
1 86 NITRO-EXPLOSIVES.
composition much the lines of the older powder, but it is
quite free from smoke, and leaves no residue whatever.
The E.G. Powder. — This is one of the oldest of the
nitro powders. It was invented by Reid and Johnson in
1 882. It is now manufactured by the E.G. Powder Company
Limited, at their factory near Dartford, Kent, and in America
by the Anglo-American E.G. Powder Company, at New
Jersey. The basis of this powder is a fine form of cellulose,
derived from cotton, carefully purified, and freed from all
foreign substances, and carefully nitrated. Its manufacture
is somewhat as follows : — Pure nitro-cotton, in the form of
a fine powder, is rotated in a drum, sprinkled with water,
and the drum rotated until the nitro-cotton has taken the
form of grains. The grains are then dried and moistened
with ether-alcohol, whereby the moisture is gelatinised, and
afterwards coloured with aurine, which gives them an orange
colour. They are then dried and put through a sieve, in
order to separate the grains which may have stuck together
during the gelatinising process.
Since its introduction soon after iSSi, E.G. powder has
undergone considerable modifications, and is now a dis-
tinctly different product from a practical point of view. It
is now and has been since 1897 what is known as a 33-grain
powder, that is to say, the old standard charge of 3 drams
by measure for a 12-bore gun weighs 33 grains, as com-
pared with 42 grains for the original E.G. and other nitro
powders. This improvement was effected by a reduction
of the barium nitrate and the use of nitro-cellulose of a
higher degree of nitration, and also more gelatinisation in
manufacture. The granules are very hard, and resist
moisture to an extent hitherto unattainable by any " bulk "
powder.
Irregularities of pressure in loading have also a minimum
effect by reason of the hardness of the grains. The colour-
ing matter used is aurine, and the small quantity of nitrate
used is the barium salt. The powder is standardised for
E.G. POWDER AND INDURITE. iS/
pressure velocity with Boulenge chronograph,* pattern and
gravimetric density by elaborate daily tests, and is con-
tinually subjected to severe trials for stability under various
conditions of storage, the result being that it may be kept
for what in practice amount to indefinite periods of time,
either in cartridges or in bulk without any alteration being
feared. The E.G. powders are used in sporting guns. No. I
and No. 2 E.G. are not at present manufactured, E.G. No. 3
having taken their place entirely. Since 1890 these powders
have been manufactured under the Borland-Johnson patents,
these improved powders being for some time known as the
J.B. powders. The E.G. No. I was superseded by the E.G.
No. 2, made under the Borland-Johnson patents, and this
in its turn by the E.G. No. 3 (in 1897).
Indurite is the invention of Professor C. E. Munroe, of
the U.S. Naval Torpedo Station. It is made from insoluble
nitro-cotton, treated in a particular manner by steam, and
mixed with nitro-benzene. The Dupont powder is very
similar to Indurite. M. E. Leonard, of the United States,
invented a powder consisting of 75 parts of nitro-glycerine,
25 parts of gun-cotton, 5 parts of lycopodium powder, and
4 parts of urea crystals dissolved in acetone. The French
smokeless powder, Vielle poudre (pouclre B), used in the
Lebel rifle, is a mixture of nitro-cellulose and tannin, mixed
with barium and potassium nitrates. It gives a very feeble
report, and very little bluish smoke. The Nobel Company
is said to be perfecting a smokeless powder in which the
chief ingredients are nitro-amido- and tri-nitro-benzene.
C. O. Lundholm has patented (U.S. Pat., 701,591, 1901) a
smokeless powder containing nitro-glycerine 30, nitro-
* Invented in 1869 by Major Le Boulenge, Belgian Artillery. It
is intended to record the mean velocity between any two points, and
from its simplicity and accuracy is largely employed. Other forms
have been invented by Capt. Breger, French Artillerie de la Marine,
and Capt. Holden, R.A.
1 88 NITRO-EXPLOSIVES.
cellulose 60, diamyl phthalate 10 (or diamyl phthalate 5,
and mineral jelly 5). The diamyl phthalate is added, with
or without the mineral jelly to nitro-glycerine and nitro-
cellulose.
Walsrode Powder. — The smokeless powder known as
Walsrode powder consists of absolutely pure gelatinised
nitro-cellulose, grained by a chemical not a mechanical
process, consequently the grains do not need facing with
gelatine to prevent their breaking up, as is the case with
many nitro powders. For this same reason, as well as from
the method of getting rid of the solvent used, the Walsrode
has no tendency whatever to absorb moisture. In fact, it
can lie in water for several days, and when taken out and
dried again at a moderate temperature will be found as
good as before. Nor is it influenced by heat, whether dry
or damp, and it can be stored for years without being in
the least affected. It is claimed also that it heats the
barrels of guns much less than black powder, and does not
injure them:
The standard charge is 30 grains, and it is claimed that
with this charge Walsrode powder will prove second to
none. A large cap is necessary, as the grains of this powder
are very hard, and require a large flame to properly ignite
them. In loading cartridges for sporting purposes, an extra
felt wad is required to compensate for the small space
occupied by the charge ; but for military use the powder
can be left quite loose. The gas pressure of this powder is
low (in several military rifles only one-half that of other
nitros), and the recoil consequently small ; and it is claimed
that with the slight increase of the charge (from 29 to 30
grs.) both penetration and initial velocity will be largely
increased, whilst the gas pressure and recoil will not be
greater.
This powder was used at Bisley, at the National Rifle
Association's Meeting, with satisfactory results. It is made
by the Walsrode Smokeless and Waterproof Gunpowder
COOPPAL POWDER AND AMBERITE. 189
Company. The nitro-cotton is gelatinised by means of
acetic ether, and the skin produced retards burning. The
nitro-cotton is mixed with acetic ether, and when the
gelatinisation has taken place, the plastic mass is forced
through holes in a metal plate into strips, which are then
cut up into pieces the size of grains. The M.H. Walsrode
powder is a leaflet powder, light in colour, about 40 grains
of which give a muzzle velocity of 1,350 feet and a pressure
of 3 tons. It is, like the other Walsrode powders, water-
proof and heat-proof.
Cooppal Powder is manufactured by Messrs Cooppal
& Co. at their extensive powder works in Belgium. It con-
sists of nitro-jute or nitro-cotton, with or without nitrates,
treated with a solvent to form a gelatinised mass. There
are a great many varieties of this powder. One kind is
in the form of little squares ; another, for use in Hotchkiss
guns, is formed into 3-millimetre cubes, and is black. Other
varieties are coloured with aniline dyes of different colours.
Amberite is a nitro-cellulose powder of the 42-grain
type of sporting gunpowders, and is manufactured by
Messrs Curtis's & Harvey Limited, at their Smokeless
Powder Factory, Tonbridge, Kent. It consists of a mix-
ture of nitro-cellulose, paraffin, barium, nitrate, and some
other ingredients. It is claimed for this powder that it
combines hard shooting with safety, great penetration, and
moderate strain on the gun. It is hard and tough in grain,
and may be loaded like black powder, and subjected to hard
friction without breaking into powder, that it is smokeless,
and leaves no residue in the gun. The charge for 12 bores
is 42 grains by weight, and i-J- oz. or lyV oz. shot. The
powders known as cannonite* and ruby powder, also manu-
factured by Messrs Curtis's & Harvey Limited, are analogous
products having the same general characteristics.
For further details of cannonite, see First Edition, p. 181.
190 NITRO-EXPLOSIVES.
Smokeless Diamond, also manufactured by the above-
mentioned firm, is a nitro-cellulose powder of the 33-grain
type of sporting gunpowders. It was invented by Mr H.
M. Chapman. The manufacture of Smokeless Diamond, as
carried out at Tonbridge, is shortly as follows : — The gun-
cotton, which is the chief ingredient of this powder, is first
stoved, then mixed with certain compounds which act as
moderators, and after the solvents are added, is worked up
into a homogeneous plastic condition. It then undergoes
the processes of granulation, sifting, dusting, drying, and
glazing. In order to ensure uniformity several batches are
blended together, and stored for some time before being
issued for use.
It is claimed for this powder that it is quick of ignition,
the quickness being probably due to the peculiar structure
of the grains which, when looked at under the microscope,
have the appearance of coke. The charge for a 12 bore is
33 grains and IT\ oz. shot, which gives a velocity of 1,050
feet per second, and a pressure of 3 tons per square inch.
Greiner's Powder consists of nitro-cellulose, nitro-
benzol, graphite, and lampblack.
B.N. Powder. — This powder is of a light grey or drab
colour, perfectly opaque, and rough to the touch. It con-
sists of a mixture, nitro-cellulose and the nitrates of barium
and potassium. Its composition is as follows : —
Insoluble nitro-cellulose 29.13 parts
Soluble nitro-cellulose - 41.31 „
Barium nitrate - - 19.00 ,,
Potassium nitrate - 7.97 „
Sodium carbonate 2.03 ,,
Volatile matter - 1.43 „
This powder is a modification of the Poudre B., or
Vieille's powder invented for use in the Lebel rifle, and
which consisted of a mixture of the nitro-celluloses with
paraffin.
SMOKELESS POWDERS — NORMAL POWDER. IQI
Von Foster's Powder contains nothing but pure gela-
tinised nitro-cellulose, together with a small quantity of
carbonate of lime.
The German Troisdorf Powder is a mixture of gela-
tinised nitro-cellulose, with or without nitrates.
Maximite is the invention of Mr Hudson Maxim, and
is a nitro-compound, the base being gun-cotton. The
exact composition and method of manufacture are, how-
ever, kept secret. It is made by the Columbia Powder
Manufacturing Company, of New York, and in two forms —
one for use as a smokeless rifle powder, and the other for
blasting purposes.
Wetteren Powder. — This powder was manufactured
at the Royal Gunpowder Factory at Wetteren, and used in
the Belgian service. Originally it was a mixture of nitro-
glycerine and nitro-cellulose, with amyl acetate as solvent.
Its composition has, however, been altered from time to
time. One variety consists chiefly of nitro-cellulose, with
amyl acetate as solvent. It is of a dark brown colour, and
of the consistency of indiarubber. It is rolled into sheets
and finally granulated.
Henrite is a nitro-cellulose powder.
Normal Powder. — The Swedish powder known as
" Normal " Smokeless Powder, and manufactured by the
Swedish Powder Manufacturing Company, of Landskrona,
Sweden, and used for some years past in the Swiss Army,
is made in four forms. For field guns of 8.4 calibre, it is
used "in the form of cylindrical grains of a yellow colour,
of a diameter of .8 to .9 mm. and density of .790 — about
840 grains of it go to one gun. For rifles, it is used in the
form of grey squares, density .750, and I grm. equals about
1,014 grains. One hundred rounds of this powder, fired in
192 NITRO-EXPLOSIVES.
eighteen minutes, raised the temperature of the gun barrel
284° F. A nitro-glycerine powder, fired under the same
conditions, gave a temperature of 464° F.
This powder is said to keep well — a sample kept 3^
years gave as good results as when first made — is easy to
make, very stable, ignites easily, not very sensitive to shock
or friction, is very light, &c. Eight hundred rounds fired
from a heavy gun produced no injury to the interior of the
weapon. Samples kept for eleven months in the moist
atmosphere of a cellar, when fired gave a muzzle velocity
of 1,450 ft. sees, and pressure of 1,312 atmospheres, and
the moisture was found to have risen from 1.2 to 1.6 per
cent. After twenty-three months in the damp it contained
2 per cent, moisture, gave a muzzle velocity of 1,478 ft.
sees., and pressure of 1,356 atmospheres. In a 7.5 milli-
metre rifle, 13.8 grm. bullet, and charge of 2 grms., it gives
a muzzle velocity of 2,035 ft. sees, and a pressure of 2,200
atmospheres. In the 8.4 cm. field-gun, with charge of 600
grms., and projectile of 6.7 kilogrammes, muzzle velocity
was equal to 1,640 ft. sees, and pressure 1,750. A sample
of the powder for use in the .303 M. rifle, lately analysed
by the author, gave the following result :—
Gun-cotton - 96.21 percent.
Soluble cotton - - 1.80 „
Non-nitrated cotton trace.
Resin and other matters - - 1.99 „
100.00
The various forms of powder invented and manufactured
by Mr C. F. Hengst are chiefly composed of nitrated straw
that has been finely pulped. The straw is treated first
with acids and afterwards with alkalies, and the result is a
firm fibrous substance which is granulated. It is claimed
that this powder is entirely smokeless and flameless, that it
does not foul the gun nor heat the barrel, and is at the
same time 1 50 per cent, stronger than black powder.
The German " Troisdorf " powder consists of nitro-
TESTS OF BLACK AND NITRO POWDERS. IQ3
cellulose that has been gelatinised together with a nitrate.
Kolf s powder is also gelatinised with nitro-cellulose. The
powders invented by Mr E. J. Ryves contain nitro-glycerine,
nitro-cotton, castor-oil, paper-pulp, and carbonate of mag-
nesia. Maxim powder contains both soluble and insoluble
nitro-cellulose, nitro-glycerine, and carbonate of soda. The
smokeless powder made by the " Dynamite Actiengesell-
schaft Nobel " consists of nitro-starch 70 to 99 parts, and
of di- or tri-nitro-benzene I to 30 parts.
An American wood powder, known as Bracket's Sport-
ing Powder, consists of soluble and insoluble nitro-lignine,
mixed with charred lignine, humus, and nitrate of soda.
Mr F. H. Snyder, of New York, is the inventor of a shell
powder known as the " Snyder Explosive," consisting of 94
per cent, nitro-glycerine, 6 per cent, of soluble nitro-cotton,
and camphor, which is said to be safe in use. Experiments
were made with it in a 6-inch rifled gun, fired at a target
220 yards away, composed of twelve i-inch steel plates
welded together, and backed with 1 2-inch and 1 4-inch oak
beams, and weighing 20 tons. The shots entirely destroyed
it. The charge of explosive used was 10 Ibs. in each shell.
Comparative Tests of Black and Nitro Powders,
from " American Field." — The results given in table below
were obtained at the German Shooting Association's
grounds at Coepenick, Berlin. Penetration was calculated
by placing frames, each holding five cards of I millimetre
in thickness (equals .03937 inch), and 3 inches apart, in a
bee-line, at distances of 20 inches. Velocity, pattern, and
penetration were taken at 40 yards from the muzzle of a
12-gauge choke-bore double-barrel gun. Gas pressure was
taken by a special apparatus. All shells were loaded with
ij oz. of No. 3 shot, equal to 120 pellets, and the number
given below represents the average number in the 3O-inch
pattern. The number of sheets passed through gives the
average penetration. One atmosphere equals pressure
equal to I kilogramme (2.2 Ibs.) on the square centimetre,
N
194
NITRO-EXPLOSIVES.
hence 1,000 atmospheres equal 2,200 Ibs. on the square
centimetre. The E.G., Schultze, and Walsrode powders
were loaded in Eley's special shells, 2| inches long. The
averages were taken from a large number of shots, and
the same series of shots fired under precisely the same
conditions.
Gas
Pressure.
Velocity.
Pattern.
Penetra-
tion.
Atmospheres.
Metres.
Sheets.
Fine-grained black
powder, standard
charge -
514.2
280
78.6 = 66%
19.0
Coarse-grained black
powder, standard
charge -
4734
281.4
78.2 = 65%
194
Schultze powder, 42
grains -
921.0
290.0
64.2 = 54%
20.2
Schultze powder, 45
grains -
1052.8
305.8
52.2=42%
20.6
E.G. smokeless, 42
grains -
920.2
298.4
81.4 = 67%
18.8
Walsrode, 29 grains -
586.4
280.6
83.0 = 69%
19.0
Barometer, 760 mm. Thermometer, 30° C. Hydrometer = 65.
Wind, S.W.
Picric Powders. — The chief of these is Melinite, the
composition of which is not known with certainty. It is
believed to be melted picric acid together with gun-cotton
dissolved in acetone or ether-alcohol. Walke gives the
following proportions — 30 parts of tri-nitro-cellulose dis-
solved in 45 parts of ether-alcohol (2 to i), and 70 parts of
fused and pulverised picric acid. The ether-alcohol mixture
is allowed to evaporate spontaneously, and the resulting
cake granulated. The French claim, however, that the
original invention has been so modified and perfected that
the melinite of to-day cannot be recognised in the earlier
product. Melinite has a yellow colour, is almost without
crystalline appearance, and when ignited by a flame or
PICRIC POWDERS — LYDDITE, ETC. 195
heated wire, it burns with a reddish-yellow flame, giving off
copious volumes of black smoke. Melinite as at present
used is said to be a perfectly safe explosive, both as regards
manufacture, handling, and storage.
Lyddite* the picric acid explosive used in the British
service, is supposed to be identical with the original melinite,
but its composition has not been made public.
Picrates are more often used than picric acid itself in
powders. One of the best known is Brugerds Powder •, which
is a mixture of 54 parts of picrate of ammonia and 45 parts
of saltpetre. It is stable and safe to manufacture. It has
been used in the Chassepot rifle with good results, gives little
smoke, and a small residue only of carbonate of potash.
The next in importance is Designolle's Powder, made
at Bouchon, consisting of picrate of potash, saltpetre, and
charcoal. It was made in three varieties, viz., for rifles, big
guns, and torpedoes and shells. These powders are made
much in the same way as gunpowder. The advantages
claimed for them over gunpowder are, greater strength,
comparative absence of smoke, and freedom from injurious
action on the bores of guns.
Emmensite is the invention of Dr Stephen Emmens, of
the United States. The Emmens " crystals " are produced
by treating picric acid with fuming nitric acid of specific
gravity of 1.52. The acid dissolves with the evolution of
red fumes. The liquid, when cooled, deposits crystals,
stated to be different to picric acid, and lustrous flakes.
These flakes, when heated in water, separate into two new
bodies. One of these enters into solution and forms
crystals unlike the first, while the other body remains
undissolved. The acid crystals are used mixed with a
nitrate.
Emmensite has been subjected to experiment by the
direction of the U.S. Secretary for War, and found satis-
* Schimose, the Japanese powder, is stated to be identical with
Lyddite and Melinite (Chem. Centr.^ 1906, i, 1196).
196 NITRO-EXPLOSIVES.
factory. A sample of Emmensite, in the form of a coarse
powder, was first tried in a pistol, and proved superior in
propelling power to ordinary gunpowder. When tested
against explosive gelatine, it did very good work in shatter-
ing iron plates. It is claimed for this explosive that it
enjoys the distinction of being the only high explosive
which may be used both for firearms and blasting. This
view is supported by the trials made by the American War
Office authorities, and shows Emmensite to be a useful
explosive both for blasting and as a smokeless powder. Its
explosive power, as tested, is 283 tons per square inch, and
its specific gravity is 1.8.
Abel proposed to use picric acid for filling shells. His
Picric Powder consisted of 3 parts of saltpetre, and 2 of
picrate of ammonia. Victorite consists of chlorate of
potash, picric acid, and olive oil, and with occasionally
some charcoal. It has the form of a coarse yellowish grey
powder, and leaves an oily stain on paper, and it is very
sensitive to friction and percussion. The composition is as
follows: — KClO3 = 8o parts; picric acid, no parts; salt-
petre, 10 parts ; charcoal, 5 parts. It is not manufactured
in England. Tschiners Powder is very similar to Victorite
in composition, but contains resin. A list of the chief picric
powders will be found in the late Colonel J. P. Cundill,
R.A.'s " Dictionary of Explosives."
CHAPTER VII.
ANALYSIS OF EXPLOSIVES.
Kieselguhr Dynamite — Gelatine Compounds — Tonite — Cordite — Vaseline-
Acetone — Scheme for Analysis of Explosives — Nitro-Cotton — Solubility
Test — Non-Nitrated Cotton — Alkalinity — Ash and Inorganic Matter —
Determination of Nitrogen — Lunge's, Champion and Pellet's, Schultze-
Tieman, KjeldahFs Methods — Celluloid — Picric Acid and Picrates —
Resinous and Tarry Matters — Sulphuric Acid and Hydrochloric Acid —
Oxalic Acid — Nitric Acid — Inorganic Impurities — General Impurities and
Adulterations — Potassium Picrate and Picrates of the Alkaloids — Analysis
of Glycerine —Residue, Silver Test, Nitration, Total Acid Equivalent,
Neutrality — Free Fatty Acids — Combined Fatty Acids — Impurities —
Oleic Acid, Sodium Chloride, &c. — Determination of Glycerine — Waste
Acids — Sodium Nitrate— Mercury Fulminate — Cap Composition.
Kieselguhr Dynamite. — The material generally consists
of 75 per cent, of nitro-glycerine and 25 per cent, of
the infusorial earth kieselguhr. The analysis is very
simple, and may be conducted as follows : — Weigh out
about 10 grms. of the substance, and place over calcium
chloride in a desiccator for some six to eight days, and
then re-weigh. The loss of weight gives the moisture.
This will generally be very small, probably never more
than I per cent, and usually less.
Mr James O. Handy, in order to save time, proposes to
dry dynamite in the following manner. He places I grm.
of the material in a porcelain crucible I inch in diameter.
The crucible is then supported at the bottom of an extra
wide-mouthed bottle of about 600 c.c. capacity. Air, which
has been dried by bubbling through strong sulphuric acid,
is now drawn over the surface of the sample for three
hours by means of an ordinary aspirator. The air should
pass approximately at the rate of 10 c.c. per second. The
198 NITRO-EXPLOSIVES.
tube by which the dry air enters the bottle extends to
within I inch of the crucible containing the dynamite. An
empty safety bottle is connected with the inlet, and another
with the outlet of the wide-mouthed bottle. The first
guards against the mechanical carrying over by the air
current of sulphuric acid from the acid bottle into the
sample, whilst the second prevents spasmodic outbursts of
water from the exhaust from reaching the sample. The
method also gave satisfactory results with nitro-glycerine.
The dry substance may now be wrapped in filter paper, the
whole weighed, and the nitro-glycerine extracted in the
Soxhlet apparatus with ether. The ether should be distilled
over at least twenty-four times.
I have found, however, that much quicker, and quite as
accurate, results may be obtained by leaving the dynamite
in contact with ether in a small Erlenmeyer flask for twenty-
four hours — leaving it overnight is better — and decanting,
and again allowing the substance to remain in contact with
a little fresh ether for an hour, and finally filtering through
a weighed filter, drying at 100° C., and weighing. This
gives the weight of the kieselguhr. The nitro-glycerine
must be obtained by difference, as it is quite useless to
evaporate down the ethereal solution to obtain it, as it is
itself volatile to a very considerable extent at the tempera-
ture of evaporation of the ether, and the result, therefore,
will always be much too low. The dry guhr can, of course,
be examined, either qualitatively or quantitatively, for other
mineral salts, such as carbonate of soda, &c. An actual
analysis of dynamite No. I made by the author at Hayle
gave — Moisture, 0.92 per cent. ; kieselguhr, 26.15 per cent. ;
and nitro-glycerine, 72.93 per cent., the last being obtained
by difference.
Nitro-Glycerine. — It is sometimes desired to test an
explosive substance for nitro-glycerine. If an oily liquid is
oozing from the substance, soak a drop of it in filter paper.
If it is nitro-glycerine it will make a greasy spot. If the
ANALYSIS OF GELATINE DYNAMITE. 199
paper is now placed upon an iron anvil, and struck with an
iron hammer, it will explode with a sharp report, if lighted
it burns with a yellowish to greenish flame, emitting a
crackling sound, and placed upon an iron plate and heated
from beneath, it explodes sharply.
If a few drops of nitro-glycerine are placed in a test
tube, and shaken up with methyl-alcohol (previously tested
with distilled water, to see that it produces no turbidity),
and filtered, on the addition of distilled water, the solution
will become milky, and the nitro-glycerine will separate
out, and finally collect at the bottom of the tube.
If to a solution of a trace of nitro-glycerine in methyl-
alcohol, a few drops of a solution, composed of I volume of
aniline, and 40 volumes sulphuric acid (1.84) be added, a
deep purple colour will be produced. This colour changes
to green upon the addition of water. If it is necessary to
determine the nitro-glycerine quantitatively in an explosive,
the scheme on page 213 may be followed. Ether is the
best solvent to use. Nitrogen should be determined in the
nitrometer.
Gelatine Compounds. — The simplest of these com-
pounds is, of course, blasting gelatine, as it consists of
nothing but nitro-cotton and nitro-glycerine, the nitro-
cellulose being dissolved in the glycerine to form a clear
jelly, the usual proportions being about 92 per cent, of
nitro-glycerine to 8 per cent, nitro-cotton, but the cotton is
found as high as 10 per cent, in some gelatines. Gelatine
dynamite and gelignite are blasting gelatines, with varying
proportions of wood-pulp and saltpetre (KNO3) mixed with
a thin blasting gelatine. The method of analysis is as
follows : — Weigh out 10 grms. of the substance, previously
cut up into small pieces with a platinum spatula, and place
over calcium chloride in a desiccator for some days. Re-
weigh. The loss equals moisture. This is generally very
small. Or Handy's method may be used. The dried
sample is then transferred to a small thistle-headed funnel
2OO NITRO-EXPLOSIVES.
which has been cut off from its stem, and the opening
plugged with a little glass wool, and round the top rim of
which a piece of fine platinum wire has been fastened, in
order that it may afterwards be easily removed from the
Soxhlet tube. The weight of this funnel and the glass
wool must be accurately known. It is then transferred to
the Soxhlet tube and exhausted with ether, which dissolves
out the nitro-glycerine. The weighed residue must after-
wards be treated in a flask with ether-alcohol to dissolve
out the nitro-cotton.
But the more expeditious method, and one quite as
accurate, is to transfer the dried gelatine to a conical
Erlenmeyer flask of about 500 c.c. capacity, and add 250
c.c. of a mixture of ether-alcohol (2 ether to I alcohol), and
allow to stand overnight. Sometimes a further addition of
ether-alcohol is necessary. It is always better to add another
300 c.c., and leave for twenty minutes or so after the solu-
tion has been filtered off. The undissolved portion, which
consists of wood-pulp, potassium nitrate, and other salts, is
filtered off through a linen or paper filter, dried and weighed.
Solution. — The ether-alcohol solution contains the
nitro-cotton. and the nitro-glycerine in solution.* To this
solution add excess of chloroform (about 100 c.c. will be
required), when the nitro-cellulose will be precipitated in
a gelatinous form. This should be filtered off through a
linen filter, and allowed to drain. It is useless to attempt
to use a filter pump, as it generally causes it to set solid.
The precipitated cotton should then be redissolved in ether-
alcohol, and again precipitated with chloroform (20 c.c. of
ether-alcohol should be used). This precaution is absolutely
necessary, if the substance has been treated with ether-
alcohol at first instead of ether only, otherwise the results
will be much too high, owing to the gelatinous precipitate
* If the substance has been treated with ether alone in the Soxhlet,
the nitro-glycerine will of course be dissolved out first, and the ether-
alcohol solution will only contain the nitro-cellulose.
ANALYSIS OF GELATINE DYNAMITE. 2OI
retaining very considerable quantities of nitro-glycerine.
The precipitate is then allowed to drain as completely as
possible, and finally allowed to dry in the air bath at 40° C.,
until it is easily detached from the linen filter by the aid of a
spatula, and is then transferred to a weighed watch-glass,
replaced in the oven, and dried at 40° C. until constant in
weight. The weight found, calculated upon the 10 grms.
taken, gives the percentage of nitro-cellulose.
The Residue left after treating the gelatine with ether-
alcohol is, in the case of blasting gelatine, very small, and
will probably consist of nothing but carbonate of soda. It
should be dried at -100° C. and weighed, but in the case of
either gelignite or gelatine dynamite this residue should be
transferred to a beaker and boiled with distilled water, and
the water decanted some eight or ten times, and the residue
finally transferred to a tarred filter and washed for some
time with hot water. The residue left upon the filter is
wood-pulp. This is dried at 100° C. until constant, and
weighed. The solution and washings from the wood are
evaporated down in a platinum dish, and dried at 100° C.
It will consist of the potassium nitrate, and any other
mineral salts, such as carbonate of soda, which should
always be tested for by adding a few drops of nitric acid
and a little water to the residue, and again evaporating to
dryness and re-weighing. From the difference in weight
the soda can be calculated, sodium nitrate having been
formed. Thus —
Mol. wt. = io6 =170
(170- 106 = 64) and x
where x equals grms. of sodium carbonate in residue, and d
equals the difference in weight of residue, before and after
treatment with nitric acid.
The nitro-glycerine is best found by difference, but if
desired the solutions from the precipitation of the nitro-
cellulose may be evaporated down upon the water bath at
202 NITRO-EXPLOSIVES.
30° to 40° C., and finally dried over CaCl.? until no smell of
ether or chloroform can be detected, and the nitro-glycerine
weighed. It will, however, always be much too low. An
actual analysis of a sample of gelatine dynamite gave the
following result : —
Nitro-cellulose (collodion) - - 3-819 per cent.
Nitro-glycerine _ _ _ 66.691 „
Wood-pulp ----- 16.290 ,,
KNO3- - 12.890 „
Na2CO3 Nil.
Water - - - 0.340 „
This sample was probably intended to contain 30 per
cent, of absorbing material to 70 per cent, of explosive
substances. Many dynamites contain other substances than
the above, such as paraffin, resin, sulphur, wood, coal-dust,
charcoal, also mineral salts, such as carbonate of magnesia,
chlorate of potash, &c. In these cases the above-described
methods must of course be considerably modified. Paraffin,
resin, and most of the sulphur will be found in the ether
solution if present. The solution should be evaporated (and
in this case the explosive should in the first case be treated
with ether only, and not ether-alcohol), and the residue
weighed, and then treated on the water bath with a solution
of caustic soda. The resin goes into solution, and is sepa-
rated by decantation from the residue, and precipitated by
hydrochloric acid, and collected on a tarred filter (dried at
1 00° C.), and dried at 100° C. and weighed. The nitro-
glycerine residue is treated with strong alcohol, decanted,
and the residue of paraffin and sulphur washed with alcohol,
dried, and weighed.
To separate the paraffin from the sulphur the residue
is heated with a solution of ammonium sulphide. After
cooling the paraffin collects as a crust upon the surface of
the liquid, and by pricking a small hole through it with a
glass rod the liquid underneath can be poured off, and the
paraffin then washed with water, dried, and weighed.
Sulphur is found by difference. Mr F. W. Smith (Jour.
GELATINE DYNAMITE, GELIGNITE, ETC. 203
Amer. Chem. Soc., 1901, 23 [8], 585-589) determines the
sulphur in dynamite gelatine as follows : — About 2 grms.
are warmed in a 100 c.c. silver crucible on the water bath
with an alcoholic solution of sodium hydroxide, and where
the nitro-glycerine is decomposed, the liquid is evaporated
to dryness. The residue is fused with 40 grms. of KOH
and 5 grms. of potassium nitrate, the mass dissolved in
dilute acetic acid and filtered, and the sulphates precipitated
in the usual way. If camphor is present, it can be extracted
with bisulphide of carbon after the material has been treated
with ether-alcohol. In that case the sulphur, paraffin, and
resin will also be dissolved. The camphor being easily
volatile, can be separated by evaporation. Let the weight
of the extract, freed from ether-alcohol before treatment
with bisulphide of carbon, equal A, and the weight of extract
after treatment with CS2 and evaporation of the same equal
B ; and weight of the residue which is left after evaporation
of the CS2 and the camphor in solution equal C, the per-
centage of camphor will be A — B — C. The residue C may
contain traces of nitro-glycerine, resin, or sulphur.
Camphor may be separated from nitro-glycerine by
means of CS2. If the solution of camphor in nitro-glycerine
be shaken with CS2, the camphor and a little of the nitro-
glycerine will dissolve. The bisulphide solution is decanted,
or poured into a separating funnel and separated from the
nitro-glycerine. The two solutions are then heated on the
water bath to 20° C. and then to 60° C., and afterwards in
a vacuum over CaCl2 until the CS2 has evaporated from
them. The camphor evaporates, and leaves the small
quantity of nitro-glycerine which had been dissolved with
it. The other portion is the nitro-glycerine, now free from
CS2. The two are weighed and their weights added together,
and equals the nitro-glycerine present. There is a loss of
nitro-glycerine, it being partly evaporated along with the
CS2. Captain Hess has shown that it is equal to about 1.25
per cent. This quantity should therefore be added to that
found by analysis. Morton Liebschutz, in a paper in the
2O4 NITRO-EXPLOSIVES.
Moniteur Scientifique for January 1893, very rightly observes
that the variety of dynamites manufactured is very great,
all of them having a special composition which, good or bad,
is sometimes of so complicated a nature that the deter-
mination of their elements is difficult
The determination of nitro-glycerine in simple dyna-
mite No. i is easy ; but not so when the dynamite
contains substances soluble in ether, such as sulphur,
resin, paraffin, and naphthalene. After detailing at length
the methods he employs, he concludes with the observation
that the knowledge of the use of acetic acid — in which
nitro-glycerine dissolves — for the determination of nitro-
glycerine may be serviceable. Mr F. W. Smith* gives the
following indirect method of determining nitro-glycerine in
gelatine dynamite, &c. About 15 grms. of the sample are
extracted with chloroform in a Soxhlet apparatus, and the
loss in weight determined. In a second portion the mois-
ture is determined. A third portion of about 2 grms. is
macerated with ether in a small beaker, the ethereal ex-
tract filtered, and the process of extraction repeated
three or four times. The united filtrates are allowed to
evaporate spontaneously, and the residue warmed gently
on the water bath with 5 c.c. of ammonium sulphide
solution, and 10 c.c. of alcohol until the nitro-glycerine is
decomposed, after which about 250 c.c. of water and sufficient
hydrochloric acid to render the liquid strongly acid, are
added, and the liquid filtered. The precipitate is washed
free from acid, and then washed through the filter with
strong alcohol and chloroform into a weighed platinum
dish, which is dried to constant weight at 50° C. The
contents of the dish are now transferred to a silver crucible,
and the sulphur determined. This amount of sulphur,
deducted from the weight of the contents of the platinum
dish, gives the quantity of substances soluble in chloroform
* " Notes on the Analysis of Explosives," Jour. Amer. Chem. Soc.,
1901, 23 [8], 585-589-
ANALYSIS OF TONITE. 205
with the exception of the nitre-glycerine, moisture, and
sulphur. The amount of the former substances plus the
moisture and sulphur, deducted from the total loss on
extraction with chloroform, gives the quantity of nitro-
glycerine. Nitro-benzene may be detected, according to
J. Marpurgo, in the following manner : — In a porcelain
basin are placed two drops of liquid phenol, three drops
of water, and a fragment of potash as large as a pea. The
mixture is boiled, and the aqueous solution to be tested
then added. On prolonged boiling nitro-benzene produces
at the edge of the liquid a crimson ring, which on the
addition of a solution of bleaching powder turns emerald-
green. And nitro-glycerine in ether solution, by placing a
few drops of the suspected solution, together with a drop
or two of aniline, upon a watch-glass, evaporating off the
ether, and then adding a drop of concentrated sulphuric
acid to the residue, when, if nitro-glycerine is present, the
H2SO4 will strike a crimson colour, due to the action of
the aniline sulphate upon the nitric acid liberated from the
nitro-glycerine.
Tonite. — The analysis of this explosive is a compara-
tively easy matter, and can be performed as follows : —
Weigh out 10 grms., or a smaller quantity, and boil with
water in a beaker, decanting the liquid four or five times,
and filter. The aqueous solution will contain the nitrate
of barium. Then put the residue on the filter, and wash
two or three times with boiling water. Evaporate the
filtrate to dryness in a platinum dish. Dry and weigh.
This equals the Ba(NO3)2. If the sample is tonite No. 3,
and contains di-nitro-benzol, treat first with ether to dis-
solve out this substance. Filter into a dish, and evaporate
off the ether, and weigh the di-nitro-benzol, and after-
wards treat residue with water as before. The residue is
dried and weighed, and equals the gun-cotton present. It
should then be treated with a solution of ether-alcohol in
a conical flask, allowed to stand some three hours, then
206 NITRO-EXPLOSIVES.
filtered through a weighed filter paper, dried at 40° C, and
weighed. This will give the gun-cotton, and the difference
between this last weight and the previous one will give the
collodion-cotton. A portion of the residue containing both
the gun-cotton and the soluble cotton can be tested in the
nitrometer, and the nitrogen determined.
Cordite. — This explosive consists of gun-cotton (with
a little collodion-cotton in it as impurity), nitro-glycerine,
and vaseline — the proportions being given as 30 per cent,
nitro-glycerine, 65 per cent, gun-cotton, and 5 per cent,
vaseline. Its analysis is performed by a modification of
the method given for gelatines. Five grms. may be
dissolved in ether-alcohol in a conical flask, allowed to
stand all night, and then filtered through a linen filter.
The residue is washed with a little ether, pressed, and
dried at 40° C., and weighed. It equals the gun-cotton.
The solution contains the nitro-glycerine, soluble cotton,
and vaseline. The cotton is precipitated with chloroform,
filtered off, dried, and weighed. The two ether-alcohol
solutions are mixed, and carefully evaporated down in a
platinum dish upon the water bath at a low temperature.
The residue is afterwards treated with strong 80 per cent,
acetic acid, which dissolves out any nitro-glycerine left in
it. The nitro-glycerine is then obtained by difference, or
the method suggested to me privately by Mr W. J.
Williams may be used. The residue obtained by evapora-
tion of the ether-alcohol solution, after weighing, is treated
with alcoholic potash to decompose the nitro-glycerine,
water is added and the alcohol evaporated off. Some ether
is then added, and the mixture shaken, and the ether separ-
ated and evaporated, and the residue weighed as vaseline.
The moisture should, however, be determined by the
method devised by Mr Arthur Marshall, F.I.C., of the
Royal Gunpowder Works, Waltham Abbey, which is
carried out as follows : — The cordite or other explosive
is prepared in the manner laid down for the Abel heat test,
ANALYSIS OF CORDITE.
207
that is to say, it is ground in a small mill, and that portion
is selected which passes through a sieve having holes of the
size of No. 8 wire gauge, but not through one with holes No.
14 wire gauge.
The form of apparatus used is shown in Fig. 40. It con-
sists of an aluminium dish A, having the dimensions shown,
and the glass cone B weighing not more than 30 grms.
Five grms. of the cordite are weighed
into the aluminium dish A. This
is covered with the cone B, and the
whole is accurately weighed, and is
then placed upon a metal plate
heated by steam from a water bath.
It is left upon the bath until all the
moisture has been driven off, then it
is allowed to cool for about half-an-
hour in a desiccator and is weighed.
The loss in weight gives accurately
the moisture of the sample. For
cordite of the original composition,
one hour's heating is sufficient to
entirely drive off the moisture ; for
modified cordite containing 65 per
cent, of gun-cotton, two hours is
enough, provided that there be not
more than 1.3 per cent, of moisture
present.
If the proportion of nitro-glycer- CORDITE.
ine be higher, a longer heating is
necessary. The aluminium dish must not be shallower
than shown in the figure, for if the distance between the
substance and the edge of the glass cone be less than half
an inch, some nitro-glycerine will be lost. Again, the sample
must not be ground finer than stated, else some of the
moisture will be lost in the grinding and sieving operations,
and the result will be too low. In order to be able to
drive off all the moisture in the times mentioned, it is
i*- 2/4' y
Thickness '/32
FIG. 40. — MARSHALL'S APPARA-
TUS FOR MOISTURE IN
208 NITRO-EXPLOSIVES.
essential that the glass cone shall not fit too closely on the
aluminium dish, consequently the horizontal ledge round
the top of the dish should be bent, so as to render it slightly
untrue, and leave a clearance of about 0.02 inch in some
places. If these few simple precautions be taken, the
method will be found to be very accurate. Duplicate
determinations do not differ more than o.oi per cent.*
The Vaseline (C16H34), or petroleum jelly, used has a
flash-point of 400° F. It must not contain more than 0.2
per cent, volatile matter when heated for 12 hours on the
water bath, and should have a specific gravity of 0.87 at
100° F., and a melting point of 86° F. It is obtained during
the distillation of petroleum, and consists mainly of the
portions distilling above 200° C. It boils at about 278° C.
Acetone (CH3CO.CH3), or dimethyl ketone, is formed
when iso-propyl alcohol is oxidised with potassium bichro-
mate and sulphuric. It is also produced in considerable
quantities during the dry distillation of wood, and many
other organic compounds. Crude wood spirit, which has
been freed from acetic acid, consists in the main of a
mixture of acetone and methyl-alcohol. The two sub-
stances may be roughly separated by the addition of
calcium chloride, which combines with the methyl-alcohol.
On subsequent distillation crude acetone passes over, and
may be purified by conversion into the bisulphite compound.
Acetone is usually prepared, however, by the dry dis-
tillation of crude calcium or barium acetate.
(CH3.COO)2Ca = CH3.CO.CH3-f-CaC03.
The distillate is fractionated, and the portion, boiling be-
tween 50° and 60° C., mixed with strong solution of sodium
bisulphite. The crystalline cake of acetone sodium bisul-
* " Determination of Moisture in Nitro-glycerine Explosives,"
by A. Marshall, Jour. Soc. Chem. Ind., Feb. 29, 1904, p. 154.
ANALYSIS OF ACETONE. 2OQ
phite, which separates on standing, is well pressed, to free
it from impurities, decomposed by distillation with dilute
sodium carbonate, and the aqueous distillate of pure acetone
dehydrated over calcium chloride. Acetone is a colourless,
mobile liquid of sp. gr. .792 at 20° C, it boils at 56.5° C,
has a peculiar, pleasant, ethereal odour, and is mixible with
water, alcohol, and ether in all proportions.
The acetone used in the manufacture of cordite should
conform to the following specification : —
SPECIFICATION FOR ACETONE.
1. The acetone to be not more than 0.802 specific gravity at 60° F.
When mixed with distilled water it must show no turbidity, and must
leave no residue on evaporation at 212° F. On distillation, four-fifths
by volume of the quantity taken must distil over at a temperature not
exceeding 138° F. The residual matter left after this distillation must
not contain, besides acetone, any ingredient that is not a bye-product
incidental to the manufacture of acetone.
2. One c.c. of o.io per cent, solution in distilled water of pure
permanganate of potash, added to 100 c.c. of the acetone, must retain
its distinctive colour for not less than 30 minutes. This test should be
made at a temperature of 60° F.
3. The acetone tested by the following method must not show
more than 0.005 Per cent- °f acid, calculated to acetic acid : —
To 50 c.c. of the sample diluted with 50 c.c. of distilled water, with
2 c.c. of phenol-phthalein solution (i gramme to 1,000 c.c. of 50 per
N
cent, alcohol) added as an indicator, add from a burette y^ sodium
hydrate solution (i c.c. 0.0006 gramme acetic acid), and calculate to
acetic acid in the usual manner.
The water used for the dilution of the acetone must be
carefully tested for acidity, and the pipettes used for
measuring should not be blown out, as it would be possible
thus to neutralise nearly 2 c.c. of the soda solution.
The presence of water in a sample of acetone may be
detected by Schweitzer and Lungwitz's method (Chem.
Zeit., 1895, xix., p. 1384), which consists in shaking together
equal volumes of acetone and petroleum ether (boiling
point, 40° to 60° C.), when if present a separation of the
liquid in layers will take place.
O
2i6 NITRO-EXPLOSIVES.
Estimation of Acetone. — Kebler (Jour. Amer. C/iem.
Soc., 1897, 19, 316-320) has improved Squibb's modifica-
tion of Robineau and Rollins' method. The following
solutions are required : —
(i.) A 6 per cent, solution of hydrochloric acid.
(2.) A decinormal solution of sodium thiosulphate.
(3.) Alkaline potassium iodide solution prepared by
dissolving 250 grms. of potassium iodide in water, made
up to a litre ; dissolving 257 grms. of sodium hydroxide
(by alcohol) in water, likewise made up to a litre. After
allowing the latter to stand, 800 c.c. of the clear solution
are added to the litre of KI.
(4.) Sodium hypochlorite solution : 100 grms. of bleach-
ing powder (35 per cent.) are mixed with 400 c.c. of water :
to this is added a hot solution of 120 grms. of crystallised
sodium carbonate in 400 c.c. of water. After cooling, the
clear liquid is decanted, the remainder filtered, and the
filtrate made up to a litre ; to each litre is added 25 c.c. of
sodium hydroxide solution (sp. gr. 1.29).
(5.) An aqueous solution of the acetone, containing I or
2 per cent, of acetone.
(6.) Bicarbonated starch solution prepared by treating
0.125 grm- of starch with 5 c.c. of cold water, then adding
20 c.c. of boiling water, boiling a few minutes, cooling, and
adding 2 grms. of sodium bicarbonate.
To 20 c.c. of the potassium iodide solution are added
10 c.c. of the diluted aqueous acetone, an excess of the
sodium hypochlorite solution is then run in from a burette
and well shaken for a minute. The mixture is then acidified
with the hydrochloric acid solution, and while agitated, an
excess of sodium thiosulphate solution is added, the mix-
ture being afterwards allowed to stand a few minutes. The
starch indicator is then added, and the excess of thiosulphate
re-titrated. The relation of the sodium hypochlorite solu-
tion to the sodium thiosulphate being known, the percentage
of acetone can be readily calculated.*
* See " The Testing of Acetone," Conroy, Jour. Soc. Chem. Ind.,
3 ist March 1900, vol. xix.
ANALYSIS OF ACETONE. 211
Dr S. J. M. Auld has recently (Jour. Chem. Soc., Feb.
15, 1906, vol. xxv.) worked out a volumetric method for
the estimation of acetone, depending on the formation of
bromoform, and its subsequent hydrolysis with alcoholic
potash. The hydrolysis is probably expressed thus —
as it has been shown by Hermann and Long that exactly
3 volumes of carbon monoxide to I of ethylene are evolved.
The residual potassium bromide is estimated by means of
standard silver nitrate solution. Bromoform is specially
suitable for this purpose for several reasons. It is very
readily formed by the action of bromine and potash on
acetone, and although very volatile in steam, it is not liable
to loss due to its own evaporation. Further, its high molec-
ular weight and large percentage of bromine conduce to
accurate results, 58 grms. of acetone being responsible for
the formation of 357 grms. of KBr. The method of carry-
ing out the analysis is as follows : —
A known quantity of the solution to be tested, contain-
ing acetone to the extent of o.i to 0.2 grm., is pipetted into
a 500 c.c. round-bottom flask, diluted with a little water,
and mixed with 20 to 30 c.c. of a 10 per cent, solution of
caustic potash. The flask is connected with a long reflex
condenser, and is also fitted with a dropping funnel con-
taining a solution of bromine in potassium bromide (200
grms. of Br and 250 grms. of KBr to I litre of water). The
bromine solution is allowed to flow into the mixture until
it has acquired a faint yellow tinge, the flask and its con-
tents being then heated on the water bath at about 70° C.
for half-an-hour. Bromine solution is added drop by drop
until the slight coloration is permanent, excess of bromine
being got rid of by boiling for a minute or two with a little
more caustic potash. The mixture is then distilled until
the distillate is free from bromoform, halogen being tested
for in the usual manner. Water is added to the contents
of the flask if necessary. It may be here observed that no
acetone can be detected in the distillate by means of the
212 NITRO-EXPLOSIVES.
mercuric oxide test, and free bromine is also absent. The
condenser having been washed out with a little alcohol, in
order to remove any traces of bromoform which may have
collected, the distillate and washings are mixed with 50 c.c.
of alcohol and sufficient solid caustic potash to make an
approximately 10 per cent, solution. The mixture is then
heated on the water bath under a reflux condenser until
the bromoform is completely decomposed. This generally
occupies about three-quarters of an hour. The liquid is
allowed to cool, evaporated to smaller bulk if necessary, and
exactly neutralised with dilute nitric acid. It is then diluted
with water to 500 c.c., and an aliquot part titrated with
N
- silver nitrate solution, using potassium chromate as
indicator ; 240 parts of bromine correspond to 58 parts of
acetone. The complete analysis can be performed in one
and a half to two hours. It is imperative that the bromine
used should be pure, as crude bromine frequently contains
bromoform. The method is suitable for the estimation of
acetone in wood-spirit, the spirit being diluted to 10 times
its volume, and 5 c.c. of this solution employed for the
determination. For example —
(i.) Three c.c. of a solution containing 9.61 per cent, acetone gave
1.7850 grm. KBr. Acetone found = 9.66 per cent.
(2.) Ten c.c. of a solution containing 0.96 per cent, acetone gave
0.5847 grm. KBr. Acetone found = 0.95 per cent.
Nitro-Cotton. — The first thing upon opening a case of
wet cotton, or in receiving a sample from the " poacher,"
that requires to be determined is the percentage of water
that it contains. It is best done by weighing out about
1,000 grms. upon a paper tray, which has been previously
dried in the oven at 100° C. for some time, and become
constant in weight. The trayful of cotton is then placed
in a water oven, kept at 100° C., and dried as long as it
loses water. The loss gives the percentage of water. It
varies from 20 to 30 per cent, as a rule in " wet " cotton.
The Solubility Test.— The object of this test is to
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214 NITRO-EXPLOSIVES.
ascertain, in the case of gun-cotton, the percentage of
soluble (penta and lower nitrates) cotton that it contains,
or in the case of soluble cotton, the quantity of gun-cotton.
The method of procedure is as follows : — Five grms. of the
sample which has been previously dried at 100° C., and
afterwards exposed to the air for two hours, is transferred
to a conical flask, and 250 c.c. ether-alcohol added (2 ether
to I alcohol). The flask is then corked and allowed to
digest, with repeated shaking, for two or three hours. The
whole is then transferred to a linen filter, and when the
solution has passed through the filter, is washed with a little
ether, and pressed in a hand-screw press between folds of
filter paper. The sample is then returned to the flask, and
the previous treatment repeated, but it will be sufficient for
it to digest for one hour the second time. The filter is then
again pressed first gently by hand, then in the press, and
afterwards opened up and the ether allowed to evaporate.
The gun-cotton is then removed from the filter and trans-
ferred to a watch-glass, and dried in the water oven at
100° C. When dry it is exposed to the air for two hours
and weighed. It equals the amount of gun-cotton and un-
converted cotton in the 5 grms. The unconverted cotton
must be determined in a separate 5 grms. and deducted.
The method of determining the soluble cotton now used
in the Government laboratories is as follows : — Fifty grains
of the nitro-cotton are dissolved in 150 c.c. of ether-alcohol,
and allowed to stand, with frequent shakings, in a 200 c.c.
stoppered measure for six hours ; 75 c.c. of the clear solu-
tion are then drawn off by the aid of a pipette and evapo-
rated in a dish on the water bath, and finally in the water
oven at 120° F. (49° C.), until constant in weight. The
weight found equals the quantity of soluble cotton in the
75 c.c., which, multiplied by 4, equals the percentage, thus :
Suppose that 2.30 grains was the weight found, then
2-3x l$° = ^6 m -0 = 9.20 per cent.
ANALYSIS OF NITRO-CELLULOSE. 215
A method for the determination of soluble nitro-
cellulose in gun-cotton and smokeless powder has been
published by K. B. Quinan (Jour. Amer. Chem. Soc., 23 [4],
258). In this method about I grm. of the finely divided
dry sample to be analysed is placed in an aluminium cup
1.9 inch in diameter and 4J- inch deep. It is then covered
and well stirred with 50 c.c. of alcohol, 100 c.c. of ether are
then added, and the mixture is stirred for several minutes.
After removing the stirrer, the cup is lightly covered with
an aluminium lid, and is then placed in the steel cup of a
centrifugal machine, which is gradually got up to a speed
of 2,000 revolutions per minute, the total centrifugal force
at the position occupied by the cups (which become
horizontal when in rapid rotation) is about 450 Ibs. They
are rotated at the full speed for ten to twelve minutes, and
the machine is then gradually stopped. By this time the
whole of the insoluble matter will be at the bottom of the
cup, and the supernatant solution will be clear. It is drawn
off to within a- quarter of an inch of the bottom (without
disturbing the sediment), with the aid of a pipette.
Care must be taken that the solution thus withdrawn is
perfectly clear. About 10 to 15 c.c. of colloid solution and
a film of insoluble matter remain at the bottom of the cup ;
these are stirred up well, the stirrer is rinsed with ether-
alcohol, about 50 c.c. of fresh ether-alcohol are added ; the
mixture is again treated in the centrifugal apparatus for
about eight minutes ; the whole washing process is then
repeated until all soluble matter has been removed. This
may require about seven or eight (or for samples with much
insoluble matter ten or twelve or more) washings, but as the
extraction proceeds, the period of rotation may be somewhat
reduced. After extraction is completed, the insoluble matter
is transferred to a Gooch crucible with the usual asbestos
pad, dried at 100° C., and weighed. The residue may, if
wished, be dried and weighed in the aluminium cup, but
then it cannot be ignited. The whole time for an analysis
exclusive of that required for drying, is from one to two
2 1 6 NITROEXPLOSI VES.
hours— average time, ij hour. The results are satisfactory
both as to accuracy and rapidity. Acetone-soluble nitro-
cellulose may be determined by the same method.
The Unconverted or Non-nitrated Cotton. — How-
ever well the cotton has been nitrated, it is almost certain
to contain a small quantity of non-nitrated or unconverted
cotton. This can be determined thus : — Five grms. of the
sample are boiled with a saturated solution of sodium
sulphide, and then allowed to stand for forty-eight hours,
and afterwards filtered or decanted, and again boiled with
fresh solutions of sulphide, and again filtered, washed first
with dilute HC1 and then with water, dried, and weighed.
The residue is the cellulose that was not nitrated, plus ash,
&c. It should be ignited, and the weight of the ash
deducted from the previous weight.
Acetone, and acetic-ether (ethyl-acetate) may also be
used as solvents for the nitro-cellulose. Another process
is to boil the gun-cotton, &c., in a solution of sodium stannate
made by adding caustic soda to a solution of stannous
chloride, until the precipitate first formed is just re-dissolved.
This solution dissolves the cellulose nitrates, but does not
affect the cellulose. Dr Lunge found the following process
more satisfactory in the case of the more highly nitrated
products : — The reagent is an alcoholic solution of sodium-
ethylate prepared by dissolving 2 to 3 grms. of sodium in
100 c.c. of 95 per cent, alcohol, and mixing the filtered
solution with 100 c.c. of acetone. It has no effect upon
cellulose, but decomposes nitro-cellulose with the formation
of a reddish brown compound, which is soluble in water.
In the determination, 5 grms. of gun-cotton are heated to
40° or 50° C. on the water bath with 1 50 c.c. of the reagent,
the liquid being shaken at intervals for twenty to thirty
minutes ; or the mixture may be allowed to stand for a few
hours at the ordinary temperature. The brown-red solution
is decanted from the undissolved residue, and the latter
washed with alcohol and with water, by decantation, and
NITRO-CELLULOSE— ALKALINITY, ASH, ETC. 217
then on the filter with hot water, to which a little hydro-
chloric acid is added for the final washings. For ordinary
work this cellulose is dried immediately and weighed, but
in exact determinations it is washed with alcohol, again
treated with 50 c.c. of the reagent, and separated and
washed as before. The cellulose thus obtained, gives no
trace of gas in the nitrometer, and duplicate determinations
agree within o.i to 0.2 per cent, when the weight of un-
changed cellulose amounts to about 0.2 grm. Gun-cotton,
which is completely soluble in acetone, contains only traces
of cellulose, and when as much as 0.85 per cent, is present
it does not dissolve entirely. This method is not applicable
to the determination of cellulose in lower nitrated products,
and Dr Lunge attributes this to the fact that these being
prepared with less concentrated acid invariably contain
oxy-cellulose.
Alkalinity. — Five grms. of the air-dried and very finely
divided sample are taken from the centre of the slabs or
discs, and digested with about 20 c.c. of - - hydrochloric
acid, and diluted with water to about 250 c.c., and shaken
for about fifteen minutes. The liquid is then decanted,
and washed with water until the washings no longer give
an acid reaction. The solution, together with the wash-
N
ings, are titrated with - - sodium carbonate, using litmus
4
as indicator.
Ash and Inorganic Matter. — This is best determined
by mixing 2 or 3 grms. of the nitre-cotton in a platinum
crucible with shavings of paraffin, heating sufficiently to
melt the paraffin, and then allowing the contents of the
crucible to catch fire and burn away quietly. The tempera-
ture is then raised, and the carbonaceous residue incinerated,
cooled, weighed, &c., and the percentage of ash calculated.
Schjerning proceeds in the following way : — He takes 5
grms. of the nitro-cotton in a large platinum crucible, he
2l8 NITRO- EXPLOSIVES.
then moistens it with a mixture of alcohol and ether, in
which paraffin has been dissolved to saturation, and filtered
and mixed with one-fourth of its volume of water. Some
fragments of solid paraffin are then added, and the ether
set on fire. Whilst this is in progress the crucible is kept
in an oblique position, and is rotated so that the gun-cotton
may absorb the paraffin uniformly. The partially charred
residue is now rubbed down with a rounded glass rod, and
the crucible is covered and heated for from fifteen to twenty
minutes over the blow-pipe, the lid being occasionally
removed. The residue is soon converted into ash, which
is weighed, and then washed out into a porcelain basin and
treated with hydrochloric acid heated to 90° C. The oxide
of iron, alumina, lime, and magnesia are thus dissolved, and
the silica remains as insoluble residue. The rest of the
analysis is conducted according to the well-known methods
of separation. The percentage of ash as a whole is gener-
ally all that is required.
Examination of Nitrated Celluloses with Polarised
Light. — DrG. Lung£ (Jour. Amer. Chem. Soc., 1901, 23 [8],
527) has formed the following conclusions : — The most
highly nitrated products appear blue in polarised light, but
those containing between 13.9 and 13.0 per cent, of nitrogen
cannot be distinguished from each other by polarisation.
As the percentage of nitrogen rises, the blue colour becomes
less intense, and here and there grey fibres can be observed,
though not in proportion to the increase in the nitrogen.
Below 12.4 per cent, of nitrogen, the fibres show a grey
lustre, which usually appears yellow when the top light is
cut off. Below 10 per cent, of nitrogen, the structure is
invariably partially destroyed and no certain observations
possible. It is only possible to distinguish with certainty,
firstly any unchanged cellulose by its flashing up in varie-
gated (rainbow) colours ; and secondly, highly nitrated
products (from 12.75 Per cent. N upwards), by their flashing
up less strongly in blue colours. The purple transition
LUNGtt NITROMETER. 2 19
stage in the fibres containing over 11.28 per cent, of N
(Chardonnet) was not observed by Dr Lunge.
Determination of Nitrogen by Lunge Nitrometer.—
The determination of the percentage of nitrogen in a sample
of gun-cotton or collodion is perhaps of more value, and
affords a better idea of its purity and composition, than
any of the foregoing methods of examination, and taken in
conjunction with the solubility test, it will generally give
the analyst a very fair idea of the composition of his sample.
If we regard gun-cotton as the hexa-nitro-cellulosc, the
theoretical amount of nitrogen required for the formula is
14.14 per cent., and in the same way for collodion-cotton,
which consists of the lower nitrates, chiefly, however, of the
penta-nitrate, the theoretical nitrogen is 12.75 Per cent, so
that if in a sample of nitro-cotton the nitrogen falls much
lower than 14 per cent., it probably contains considerable
quantities of the lower nitrates, and perhaps some non-
nitrated cellulose as well (CGH10O5)X) which of course would
also lower the percentage of nitrogen.
The most expeditious method of determining the nitro-
gen in these nitro bodies is by the use of Lunge's nitrometer
(Fig. 41), and the best way of working the process is as
follows : — Weigh out with the greatest care 0.6 grm. of the
previously dried substance in a small weighing bottle of
about 15 c.c. capacity, and carefully add 10 c.c. of concen-
trated sulphuric acid from a pipette, and allow to stand
until all the cotton is dissolved. The nitrometer should be
of a capacity 150 to 200 c.c., and should contain a bulb of
100 c.c. capacity at the top, and should be fitted with a
Greiner and Friederich's three-way tap. When the nitro-
cotton has entirely dissolved to a clear solution, raise the
pressure tube of the nitrometer so as to bring the mercury
in the measuring tube close up to the tap. Open the tap
in order to allow of the escape of any air bubbles, and
clean the surface of the mercury and the inside of the cup
with a small piece of filter paper. Now close the tap, and
220
NITRO-EXPLOSIVES.
pour the solution of the nitro-cotton into the cup. Rinse
out the bottle with 1 5 c.c. of sulphuric acid, contained in a
pipette, pouring a little of the acid over the stopper of the
weighing bottle in case some of the solution may be on it.
Now lower the pressure tube a little, just enough to cause
the solution to flow into the bulb of the measuring tube,
when the tap is slightly opened. When the solution has
FIG. 41. — ORDINARY FORM OF LUNG& NITROMETER.
run in almost to the end, turn off the tap, wash down the
sides of the bottle, and add to the cup of the nitrometer ;
allow it to flow in as before, and then wash down the sides
of the cup with 10 c.c. of sulphuric acid, adding little by
little, and allowing each portion added to flow into the bulb
of the nitrometer before adding the next portion. Great
care is necessary to prevent air bubbles obtaining admission,
LUNG£ NITROMETER. 221
and if the pressure tube is lowered too far, the acid will
run with a rush and carry air along with it.
The solution being all in the measuring tube, the
pressure tube is again slightly raised, and the tube con-
taining the nitro-cotton solution shaken for ten minutes
with considerable violence. It is then replaced in the
clamp, and the pressure relieved by lowering the pressure
tube, and the whole apparatus allowed to stand for twenty
minutes, in order to allow the gas evolved to assume the
temperature of ttie room. A thermometer should be hung
up close to the bulb of the measuring tube. At the end
of the twenty minutes, the levels of the mercury in the
pressure and measuring tubes are equalised, and the final
adjustment obtained by slightly opening the tap on the
measuring tube (very slightly), after first adding a little
sulphuric acid to the cup, and observing whether the acid
runs in or moves up. This must be done with very great
care. When accurately adjusted, it should move neither
way. Now read off the volume of the NO gas in cubic
centimetres from the measuring tube. Read also the ther-
mometer suspended near the bulb, and take the height of
the barometer in millimetres. The calculation is very
simple.
EXAMPLE — COLLODION-COTTON.
0.6* grm. taken. Reading on measuring tube= 1 14.6 c.c. NO.
Barometer = 758 mm. Temperature = 15° C.
Since I c.c. NO = 0.6272 milligramme N, and correcting
for temperature and pressure by the formula
76ox(i-f <tf2) (^=.003665), for temperature i5° = 8oi.78,t
then
cent ntr
8oi.7x.6
The nitrogen in nitro-glycerine may of course be de-
termined by the nitrometer, but in this case it is better to
* 0.5 grm. is enough in the case of gun-cotton.
t See Table, page 244.
222
NITRO-EXPLOSIVES.
take a much smaller quantity of the substance. From o. I
to 0.2 grm. is quite sufficient. This will give from 30 to 60
c.c. of gas, and therefore a measuring tube without a 100 c.c.
bulb must be used.
EXAMPLE.
0.1048 grm. nitroglycerine taken gave 32.5 c.c. NO.
Barometer, 761 mm. Temperature, 15° C.
Therefore,
IPO x 761 x. 6272 =lg 6
8oi.78x.io48
> Ni Th I8 cent
Professor Lunge has devised another form of nitrometer
(Fig. 42), very useful in the nitrogen determination in ex-
plosives. It consists of a measuring tube, which is widened
out in the middle to a bulb, and
is graduated above and below
into YQ c.c. The capacity of the
whole apparatus is 1 30 c.c. ; that
of each portion of the tube being
30 c.c., and of the bulb 70 c.c.
The upper portion of the gradu-
ated tube serves to measure small
volumes of gas, whilst larger vol-
umes are read off on the lower
part.
F. M. Horn (Zeitschrift fiir
angewandte Cheuiie, 1892, p. 358)
has devised a form of nitrometer
(Fig. 43) which he has found
especially useful in the exam-
ination of smokeless powders.
The tap H is provided with a
wide bore through which a
weighed quantity of the powder is dropped bodily into the
bulb K. From 4 to 5 c.c. of sulphuric acid which has been
heated to 30° C. are then added through the funnel T, the
tap H being immediately closed. When the powder has
dissolved— a process which may be hastened by warming
130
FIG 42.
FIG. 43.
SOME NEW FORMS OF
NITROMETER.
NITROGEN — CHAMPION-PELLET'S METHOD. 223
the bulb very carefully — the thick solution is drawn into
the nitrometer tube N, and the bulb rinsed several times
with fresh acid, after which operation the analysis is pro-
ceeded with in the usual way.
Dr Lunge's method of using a separate nitrometer in
which to measure the NO gas evolved to the one in which
the reaction has taken place, the gas being transferred from
the one to the other by joining them by means of india-
rubber tubing, and then driving the gas over by raising the
pressure tube of the one containing the gas, the taps being
open, I have found to be a great improvement.
i c.c. NO gas at o° and 760 mm.
Equals 0.6272 milligrammes (N) nitrogen.
„ 1-343 j, nitric oxide.
„ 2.820 „ (HNO3) nitric acid.
» 3-^05 „ (NaNO3) sodium nitrate.
„ 4.523 „ (KNO3) potassium nitrate.
Champion and Pellet's Method. — This method is
now very little used. It is based upon the fact that when
nitro -cellulose is boiled with ferrous chloride and hydro-
chloric acid, all the nitrogen is disengaged as nitric oxide
(NO). It is performed as follows : — A vacuum is made in
a flask, fitted with a funnel tube, with a glass stopper on
the tube ; a delivery tube that can also be closed, and which
dips under a solution of caustic soda contained in a trough,
and the end placed under a graduated tube, also full of
caustic soda. From 0.12 to 0.16 grm. cotton dissolved in 5
to 6 c.c. of sulphuric acid is allowed to flow into the flask,
which contains the ferrous chloride and hydrochloric acid,
and in which a vacuum has been formed by boiling, and
then closing the taps. The solution is then heated, the
taps on the delivery tube opened, and the end placed under
the collecting tube, and the NO evolved collected. The
NO gas is not evolved until the solution has become some-
what concentrated. Eder substituted a solution of ferrous
sulphate in HC1 for ferrous chloride. Care must be taken
224 NITRO-EXPLOSIVES.
that the flask used is strong enough to stand the pressure,
or it will burst.
The same chemists (Couipt. Rendus, Ixxxiii. 707) also
devised the following method for determining the NO2 in
nitro-glycerine : — A known quantity of a solution of ferrous
sulphate of previously ascertained reducing power is placed
in a flask, acidified with hydrochloric acid, and its surface
covered with a layer of petroleum oil. About .5 grm. of
the nitro-glycerine is then introduced, and the flask heated
on the water bath. When the sample is completely decom-
posed, the liquid is heated to boiling to remove nitric oxide,
and the excess of ferrous sulphate ascertained by titration
with standard permanganate ; 56 of iron (Fe) oxidised by
the sample correspond to 23 of NO.2 in the sample of
nitro-glycerine.
The Schultze-Tieman Method for determining nitro-
gen in nitro - explosives, especially nitro - cellulose and
nitro-glycerine. — The figure (No. 44) shows the general
arrangement of the apparatus. I am indebted for the
following description of the method of working it to my
friend, Mr William Bate, of Hayle. To fill the apparatus
with the soda solution, the gas burette is put on the india-
rubber stopper of basin W, and firmly clamped down. Then
the taps A and C are opened, and B closed. When the
burette is filled with soda solution half-way up the funnel Y,
A and C are closed, and B opened. The arrows show the
inlet and outlet for the cooling water that is kept running
through the water jacket round the nitrometer tube. To
collect the gas, raise the nitrometer off the rubber stopper,
and place the gas tube from the decomposition apparatus
in the glass dish W and under the opening of the nitrometer.
For the estimation of nitrogen in nitro-cellulose take .5
to .65 grm., and place in the decomposition flask /(Fig. 45),
washing in with about 25 c.c. of water by alternately
opening clips D and E. The air in the flask is driven out
by boiling, whilst the air is shut off by the tube i dipping
SCHULTZE-TIEMAN APPARATUS.
225
into the basin w, which is filled with the soda lye, and tube
K is placed in the test tube R, which contains a few c.c. of
FlG. 44. — SCHULTZE-TlE.MAN APPARATUS.
P
226
NITRO-EXPLOSIVES.
water. As soon as all the air is completely driven out,
clips D and E are closed, and the gas jet is taken away.
(This flask must be a strong one, or it will burst.) Into
test tube R, 25 c.c. of concentrated solution of protochloride
of iron and 10 to 15 c.c. concentrated hydrochloric acid
are poured, which are sucked up into the developing flask f
by opening clip E, air being carefully kept from entering.
The clip E is now closed, and tube i is put underneath the
burette, and the development of NO gas is commenced by
heating the contents of the flask^ When the pressure of the
gas in the flask has become greater than the pressure of the
atmosphere, the connecting tube begins to swell at z, where-
FIG. 45. — DECOMPOSITION FLASK FOR SCHULTZE-TIEMAN METHOD.
upon clip D is opened, and the boiling continued with
frequent shaking of the bulb, until no more nitrous gas
bubbles rise up into the soda lye, the distilling over of the
HC1 causes a crackling noise, the clip D is closed, and E
opened. The burette is again put hermetically on the
indiarubber stopper in basin W, and the apparatus is left to
cool until the water discharged through P shows the same
temperature as the water flowing through (into the cooling
jacket) z. If the level of the soda solution in the tube X is
now put on exactly the same level as that in the burette by
lowering or elevating the tube X as required, the volume of
NO obtained in c.c. can be read off within -^ c.c., and the
percentage of nitrogen calculated by the usual formula.
DETERMINING NITROGEN. 227
The solution of protochloride of iron is obtained by
dissolving iron nails, &c., in concentrated HC1, the iron
being in excess. When the development of hydrogen
ceases, it is necessary to filter warm through a paper filter,
and acidify filtrate with a few drops of HCL The soda
solution used has a sp. gr. of 1.210 to 1.260; equals 25° to
30° B. The nitro-cellulose is dried in quantities of 2 grms.
at 70° C. during eight to ten hours, and then three hours in
an exiccator over H.2SO4. The results obtained with this
apparatus are very accurate. The reaction is founded upon
that of MM. Champion and Pellet's method.
The Kjeldahl Method of Determining Nitrogen. —
This method, which has been so largely used by analysts
for the determination of nitrogen in organic bodies, more
especially perhaps in manures, was proposed by J. Kjeldahl,*
of the Carlsberg Laboratory of Copenhagen. It was after-
wards modified by Jodlbauer, of Munich,f and applied to
the analysis of nitro-explosives by M. Chenel, of the
Laboratoire Centrale des Poudres, whose method of pro-
cedure is as follows : — 0.5 grm. of the finely powdered
substance is digested in the cold with a solution of 1.2 grm.
of phenol and 0.4 grm. phosphoric anhydride in 30 c.c. of
sulphuric acid. The mixture is kept well shaken until the
solution is complete. From 3 to 4 grms. of zinc-dust is
then cautiously and gradually added, the temperature of
the mass being kept down until complete reduction has
been effected. Finally, 0.7 grm. of mercury is added, and
the process continued in the usual way, according to
Kjeldahl ; that is, the liquid is distilled until all the
ammonia has passed over, and is absorbed in the standard
acid. The distillate is then titrated with standard ammonia.
The NO2 group is at the moment of solution fixed upon
* J. Kjeldahl, Zcitschrift Anal. Chem., 1883, xxii., p. 366.
t Jodlbauer, Chemischcs Centralblatt, 1886, pp. 434-484. See also
Arms and Explosives, 1893, p. 87.
228
NITRO-EXPLOSIVES.
the phenol with the production of mono-nitro-phenol, which
is afterwards reduced by the action of the zinc-dust into the
amido derivative. During the subsequent combustion, the
nitrogen of the amido -phenol becomes fixed in the state of
ammonia. M. Chenel is perfectly satisfied with the results
obtained, but he points out that the success of the operation
depends upon the complete conversion of the phenol into
the mono-nitro derivatives. This takes place whenever the
organic compound forms a clear solution in the cold sulphuric
acid mixture. Substances like collodion or gun-cotton
must be very finely divided for successful treatment. The
following table shows some of the results obtained by M.
Chenel : —
Substances Analysed.
Total Nitrogen.
Calculated.
Found.
Saltpetre (KNO3) . -
13.86
I3-9I
13.82
1373
13.96
Ammonium nitrate -
35.00
35-31
34.90
Barium nitrate -
10.72
10.67
10.62
Nitro-glycerol -
18.50
18.45
Di-nitro-benzol* 16.67
16.78
16.57
Para-nitro-phenol
10.07
10.03
Picric acid*
18.34
18.42
18.43
Ammonium picrate
22.76
22.63
22.67
Di-nitro-ortho-cresol -
14.14
14.10
13.98
Tri-nitro-meta-cresol
T7.28
17-57
17.27
* Dr Bernard Dyer obtained 18.39 Per cent- f°r picric acid and
16.54 per cent, for di-nitro-benzol.— Jour. Chem. Soc., Aug. 1895.
DETERMINING NITROGEN. 22Q
When Chenel endeavoured to apply Jodlbauer's modi-
fication of Kjeldahl's process to the examination of the
tri- and tetra-nitrated naphthalenes, he found that good
results were not obtainable, because these compounds do
not dissolve completely in the cold sulphuric acid. It may,
however, be used if they are previously converted into the
naphthylamines, according to the plan proposed by D' Aguiar
and Lautemann (Bull. Soc. Chim., vol. iii., new series, p. 256).
This is rapidly effected as follows : — Twelve grms. of iodine
are gradually added to a solution of 2 grms. of phosphorus
in about 15 or 20 c.c. of bisulphide of carbon, this solution
being contained in a flask of 250 c.c. capacity. The flask
and its contents are heated on the water bath at 100° C.
with constant attention, until the last traces of the carbon
bisulphide have distilled away. It is then cooled, and the
iodide of phosphorus is detached from the sides of the flask
by shaking, but not expelled. The next step is to add
about 0.5 to 0.6 grm. of the substance that is to be analysed,
after which 8 grms. of water are introduced, and the flask
is agitated gently two or three times. As soon as the re-
action becomes lively, the contents of the flask are well
shaken. It is usually finished about one minute after the
addition of the water. The flask is now cooled, and 25 c.c.
of sulphuric acid, together with 0.7 grm. of mercury, are
gradually added; hydriodic acid (HI) forms, and the tem-
perature of the flask must be raised sufficiently to expel it.
The remaining part of the operation is as in the ordinary
Kjeldahl process.
M. Chenel has found this process the best for the
analysis of the nitro-naphthalenes, and for impervious sub-
stances like collodion or gun-cotton. Personally, I have
never been able to obtain satisfactory results with this pro-
cess in the analysis of nitro-cellulose, and I am of opinion
that the process does not possess any advantage over the
nitrometer method, at any rate for the analysis of gun-
cotton.
230 NITRO-EXPLOSIVES.
Table giving the Percentages of Nitrogen and Oxide of
Nitrogen in Various Substances used in or as Explosives : —
NAME. FORMULA. NITROGEN NO2
p. cent. p. cent.
Nitro-glycerine - C3H6(ONO2)3. - 18.50 = 60.70
Hexa-nitro-cellulose - C12H14O4(ONOo)c H-H = 46.42
Penta-nitro-cellulose C6H8O3(ONO.,)r) ii.n = 36.50
Nitro-benzene CfiH5NO.> - - 11.38 = 37.39
Di-nitro-benzene - • C6H4(NO2)2 - 16.67 — 54-77
Tri-nitro-benzene - • C6H3(NO2)3 19.24 = 63.22
Nitro-toluene - - • C7H7NO.2 - - 10.21 — 33.49
Nitro-naphthalene - C10H7N(X 8.09 = 26.53
Di-nitro- naphthalene - C]0H6(NO2)2 - - 12.84 = 42.12
Nitro-mannite • C6H8(NO3)6 23.59 = 77.37
Nitro-starch - - C6H8O4(HNO3) 6.76 = 22.18
Picric acid (Tri-nitro-
phenol) C6H2OEI(NO2)3 - - 18.34 = 60.15
Chloro-nitro-benzene • C6H3C1(NO2)2 - 13.82 — 45.43
Ammonium nitrate - - - NH4NO3 - - - - 35.00 =
Sodium nitrate - - - NaNO:i - - - - 16.47 =
Potassium nitrate - - - KNO3 13.86 —
Nitric acid - - - HNO3 - - - -22.22 =
Barium nitrate - - - Ba(NO3)2 - - - - 10.72 =
Analysis of Celluloid. — The finely divided celluloid is
well stirred, by means of a platinum wire, with concentrated
sulphuric acid in the cup of a Lunge nitrometer, and when
dissolved the nitrogen determined in the solution in the
usual way. To prevent interference from camphor, the
following treatment is suggested by H. Zaunschirm (Chem.
Zeit., xiv., 905). Dissolve a weighed quantity of the cellu-
loid in a mixture of ether-alcohol, mixed with a weighed
quantity of washed and ignited asbestos, or pumice-stone,
dry, and disintegrate the mass, and afterwards extract the
camphor with chloroform, dry, and weigh : then extract
with absolute methyl-alcohol, evaporate, weigh, and examine
the nitro-cellulose in the nitrometer.
Picric Acid and Picrates. — Picric acid is soluble in
hot water, and to the extent of I part in 100 in. cold
water, also in ether, chloroform, glycerine, 10 per cent.
PICRIC ACID AND PICRATES. 23!
soda solution, alcohol, amylic alcohol, carbon bisulphide,
benzene, and petroleum. If a solution of picric acid be
boiled with a strong solution of potassium cyanide, a
deep red liquid is produced, owing to the formation of
potassium iso-purpurate, which crystallises in small reddish-
brown plates with a beetle-green lustre. This, by reaction
with ammonium chloride, gives ammonium iso-purpurate
(NH4C8H4N5O6), or artificial murcxide, which dies silk
and wool a beautiful red colour. On adding barium
chloride to either of the above salts, a vermilion-red pre-
cipitate was formed, consisting of barium iso-purpurate.
With ammonio-sulphate of copper, solutions of picric acid
give a bright green precipitate. Mr A. H. Allen gives the
following methods for the assay of commercial picric acid,
in his " Commercial Organic Analysis " : —
Resinous and Tarry matters are not unfrequently
present. They are left insoluble on dissolving the sample
in boiling water. The separation is more perfect if the
hot solution be exactly neutralised by caustic soda.
Sulphuric Acid, Hydrochloric Acid, and Oxalic
Acid, and their salts are detected by adding to the
filtered aqueous solution of the sample solutions of the
picrates of barium, silver, and calcium. These salts are
readily made by boiling picric acid with the carbonates
of the respective metals and filtering : other soluble salts
of these methods may be substituted for the picrates, but
they are less satisfactory.
Nitric Acid may be detected by the red fumes evolved
on warming the sample with copper turnings.
Inorganic Impurities and Picrates of Potash and
Sodium, &c., leave residues on cautious ignition.
General Impurities and Adulterations may be
232 NITROEXPLOSIVES.
detected and determined by shaking I grm. of the sample
of acid in a graduated tube with 25 c.c. of ether, the pure
acid dissolves, while any oxalic acid, nitrates, picrates,
boric acid, alum, sugar, &c., will be left insoluble, and
after removal of the ethereal liquid, may be readily
identified and determined. For the detection and deter-
mination of water and of oxalic acid, 50 c.c. of warm
benzene may be advantageously substituted for ether.
Sugar may be separated from the other impurities by
treating the residue insoluble in ether or benzene with
rectified spirit, in which sugar and boric acid alone will
dissolve. If boric acid be present, the alcoholic solution
will burn with a green flame. Mono- and di-nitrophenic
acids lower the melting point (122° C.). Their calcium
salts are less soluble than the picrate, and may be approxi-
mately separated from it by fractional crystallisation, or
by precipitating the hot saturated solution of the sample
with excess of lime water. Picric acid may be determined
by extracting the acidulated aqueous solution by agitation
with ether or benzene, and subsequently removing and
evaporating off the solvent. It may also be precipitated
as the potassium salt.
Potassium Picrate [KC6H2(NO2)3O]. When a strong
solution of picric acid is neutralised by carbonate of potash,
this salt is thrown down in yellow crystalline needles,
which require 260 parts of cold or 14 parts of hot water
for their solution. In alcohol it is much less soluble.
Ammonium Picrate is more soluble in water than
the above, and sodium picrate is readily soluble in water,
but nearly insoluble in solution of sodium carbonate.
Picrates of the Alkaloids. — Picric acid forms in-
soluble salts with many of the alkaloids, and picric acid
may be determined in the following manner : — To the
solution of picric acid, or a picrate, add a solution of
ANALYSIS OF GLYCERINE. 233
sulphate of cinchonine acidulated with H2SO4. The pre-
cipitated picrate of cinchonine [C20H24N2O(C6H2N3O7)2]
is washed with cold water, rinsed off the filter into a
porcelain crucible or dish, the water evaporated on the
water bath, and the residual salt weighed. Its weight,
multiplied by .6123, gives the quantity of picric acid in
the sample taken.
Analysis of Glycerine.* — Glycerine that is to be used
for the manufacture of nitro-glycerine should have a
minimum specific gravity of 1.261 at 15° C. This can be
determined, either by the aid of a Sartorius specific gravity
balance, or by using an ordinary specific gravity bottle.
One of i o or 25 c.c. capacity is very convenient.
Residue f left upon evaporation should not be more
than 0.25 per cent. To determine this, take 25 grms. of
the glycerine, and evaporate it at a temperature of about
160° C. in a platinum basin, and finish in an air bath.
Weigh until constant weight is obtained. Afterwards
incinerate over a bunsen burner, and weigh the ash.
Silver Test. — A portion of the sample of glycerine to
be tested should be put in a small weighing bottle, and a
quarter of its bulk of — silver nitrate solution added to
10
it, then shake it, and place in a dark cupboard for fifteen
minutes. It must be pronounced bad if it becomes black
or dark brown within that time (acrolein, formic, and
butyric acids).
The German official test for glycerine for pharma-
ceutical purposes is much more stringent. i c.c. of
glycerine heated to boiling with i c.c. of ammonia solution
* See also Sulman and Berry, Analyst, xi., 12-34, and Allen's
"Commercial Organic Analysis," vol. ii., part i.
t Organic matter up to .6 per cent, is not always prejudicial to
the nitrating quantities of a glycerine.
234 NITRO-EXPLOSIVES.
and three drops of silver nitrate solution must give neither
colour or precipitate within five minutes.
Nitration. — Fifty grms. of the glycerine are poured
from a beaker into a mixture of concentrated nitric acid
(specific gravity 1.53) and sulphuric acid (1.84), mixed
in the proportions of 3 HNO3 to 5 H2SO4 (about 400 c.c.
of mixed acids). The mixed acids should be put into a
rather large beaker, and held in the right hand in a basin
of water, and the glycerine slowly poured into them from
a smaller one held in the left. A constant rotatory motion
should be given to the beaker in which the nitration is per-
formed. When all the glycerine has been added, and the
mixture has been shaken for a few minutes longer, it is
poured into a separator, and allowed to stand for some
time. It should, if the glycerine is a good one, have
separated from the mixed acids in ten minutes, and the
line of demarcation between the nitro-glycerine and the
acid should be clear and sharp, neither should there be any
white flocculent matter suspended in the liquid. The
excess of acids is now drawn off, and the nitro-glycerine
shaken once or twice with a warm solution of carbonate of
soda, and afterwards with water alone. The nitro-glycerine
is then drawn off into a weighed beaker, the surface dried
with a piece of filter paper, and weighed ; 100 parts of a
good glycerine should yield about 230 of nitro-glycerine.
A quicker method is to take only 10 c.c. of the glycerine,
of which the specific gravity is already known, nitrate as
before, and pour into a burette, read off the volume of
nitro-glycerine in c.c. and multiply them by 1.6 (the specific
gravity of nitro-glycerine), thus: 10 grms. gave 14.5 c.c.
nitro-glycerine, and 14.5x1.6 = 23.2 grms., therefore 100
would give 232 grms. nitro-glycerine. The points to be
noted in the nitration of a sample of glycerine are : the
separation should be sharp, and within half an hour or less,
and there should be no white flocculent matter formed,
especially when the carbonate of soda solution is added.
ANALYSIS OF GLYCERINE. . 235
Total Acid Equivalent. — Mr G. E. Barton (Jour. Amer.
Chem. Soc., 1895) proposes to determine thus: 100 c.c. of
glycerine are diluted to 300 c.c. in a beaker, a few drops of
a I per cent, solution of phenolphthalein and 10 c.c. of
normal caustic soda solution are added ; after boiling, the
liquid is titrated with normal hydrochloric acid (fatty acids
are thus indicated and roughly determined).
Neutrality. — The same chemist determines the neu-
trality of glycerine thus : 50 c.c. of glycerine mixed with
100 c.c. of water and a few drops of alcoholic phenolphtha-
lein* are titrated with hydrochloric acid or sodium hy-
droxide ; not more than 0.3 c.c. normal hydrochloric acicl
or normal soda solution should be required to render the
sample neutral ; raw glycerines contain from .5 to i.o per
cent, of sodium carbonate.
Determination of Free Fatty Acids. — A weighed
quantity of the glycerine is shaken up with some neutral
ether in a separating funnel, the glycerine allowed to settle,
drawn Off, and the ether washed with three separate lots of
water. The water must have been recently boiled, and be
quite free from CO2. All the free fatty acid is now in the
ether, and no other soluble acid. A drop of phenolphtha-
lein is now added, a little water, and the acidity determined
by titration with deci-normal baryta solution, and the
baryta solution taken calculated as oleic acid.
Combined Fatty Acid. — About 30 grms. of the gly-
cerine are placed in a flask, and to it is added about half a
grm. of caustic soda in solution. The mixture is heated
for ten minutes at 150° C. After cooling some pure ether
is added to it, and enough dilute H2SO4 to render it dis-
tinctly acid. It is well shaken. All the fatty acids go into
the ether. The aqueous solution is then removed, and
* Sulman and Berry prefer litmus as indicator.
236 NITRO-EXPLOSIVES.
the ether well washed to remove all H9SO4. After the
addition of phenolphthalein the acid is titrated, and the
amount used calculated into oleic acid. From this total
amount of fatty acids the free fatty acid is deducted, and
the quantity of combined fatty acids thus obtained.
Impurities. — The following impurities may be found
in bad samples of glycerine : — Lead, arsenic, lime, chlorine,
sulphuric acid, thio-sulphates, sulphides, cyanogen com-
pounds, organic acids (especially oleic acid and fatty acids*),
rosin products, and other organic bodies. It is also said
to be adulterated with sugar and glucose dextrine. Traces
of sulphuric acid and arsenic may be allowed, also very
small traces indeed of lyne and chlorine.
The organic acids, formic and butyric acids may be
detected by heating a sample of the glycerine in a test
tube with alcohol and sulphuric acid, when, if present,
compound ethers, such as ethylic formate and butyrate, the
former smelling like peaches and the latter of pine-apple,
will be formed.
Oleic Acid, if present in large quantity, will come down
upon diluting the sample with water, but smaller quantities
may be detected by passing a current of nitrogen peroxide,
N2O4 (obtained by heating lead nitrate), through the diluted
sample, when a white flocculent precipitate of elaidic acid,
which is less soluble than oleic acid, will be thrown down.
By agitating glycerol with chloroform, fatty acids, rosin oil,
and some other impurities are dissolved, while certain others
form a turbid layer between the chloroform and the super-
natant liquid. On separating the chloroform and evapo-
rating it to dry ness, a residue is obtained which may be
further examined.
Sodium Chloride can be determined in 100 c.c. of the
* These substances often cause trouble in nitrating, white floc-cu-
lent matter being formed during the process of washing.
ANALYSIS OF GLYCERINE. 237
glycerine by adding a little water, neutralised with sodium
carbonate, and then titrated with a deci-normal solution of
silver nitrate, using potassium chromate as indicator.
Organic Impurities of various kinds occur in crude
glycerine, and are mostly objectionable. Their sum may
be determined with fair accuracy by Sulman and Berry's
method : 50 grms. of the sample are diluted with twice its
measure of water, carefully neutralised with acetic acid,
and warmed to expel carbonic acid ; when cold, a solution
of basic lead acetate is added in slight but distinct excess,
and the mixture well agitated. The formation of an
abundant precipitate, which rapidly subsides, is an indica-
tion of considerable impurity in the sample. To ascertain
its amount, the precipitate is first washed by decantation,
and then collected on a tared, or preferably a double counter-
poised filter, where it is further washed, dried at 100° to
105° C, and weighed. The precipitate and filter paper are
then ignited separately in porcelain, at a low red heat, the
residues moistened with a few drops of nitric acid and re-
ignited ; the weight of the lead oxide deducted from that
of the original precipitate gives the weight of the organic
matter precipitated by the lead. Raw glycerines contain
from 0.5 to i.o per cent.
Albuminous Matters. — An approximate determination
of the albuminous matters may be made by precipitating
with basic lead acetate as already described, and determin-
ing the nitrogen by the Kjeldahl method ; the nitrogen
multiplied by 6.25 gives the amount of albuminous matter
in the precipitate.
The Determination of Glycerine. — The acetin method
of Benedikt and Canton depends upon the conversion of
glycerine into triacetin, and the saponification of the latter,
and reduces the estimation of glycerine to an acidmetric
method. About 1.5 grm. of crude glycerine is heated to
238 NITRO-EXPLOSIVES.
boiling with 7 grms. of acetic anhydride, and 3 to 4 grms.
of anhydrous sodium acetate, under an upright condenser
for one and a half hours. After cooling, 50 c.c. of water
are added, and the mixture heated until all the triacetin
has dissolved. The liquid is then filtered into a large flask,
the residue on the filter is well washed with water, the
filtrate quite cooled, phenolphthalein is added and the
fluid exactly neutralised with a dilute (2 to 3 per cent.)
solution of alkali. Twenty-five c.c. of a 10 per cent, caustic
soda solution, which must be accurately standardised upon
normal acid, are then pipetted into the liquid, which is
heated to boiling for ten minutes to saponify the triacetin,
and the excess of alkali is then titrated back with normal
acid. One c.c. of normal acid corresponds to .03067 grm.
of glycerine.
Precautions. — The heating must be done with a reflux
condenser, the triacetin being somewhat volatile. The
sodium acetate used must be quite anhydrous, or the con-
version of the glycerine to triacetyl is imperfect. Triacetin
in contact with water gradually decomposes. After acety-
lation is complete, therefore, the operations must be con-
ducted as rapidly as possible. It is necessary to neutralise
the free acetic acid very cautiously, and with rapid agita-
tion, so that the alkali may not be locally in excess.
The Lead Oxide Method, — Two grms. of sample are
mixed with about 40 grms. of pure litharge, and heated in
an air bath to 1 30° C. until the weight becomes constant,
care being taken that the litharge is free from such lead
compounds and other substances as might injuriously affect
the results, and that the heating of the mixture takes place
in an air bath free from carbonic acid. The increase in
weight in the litharge, minus the weight of substance not
volatilisable from 2 grms. of glycerine at 160° C., multiplied
by the factor 1.243, ig taken as the weight of glycerine in
the 2 grms. of sample. The glycerine must be fairly pure,
WASTE ACIDS AND SODIUM NITRATE. 239
and free from resinous substances and SO3, to give good
results by this process.
Analysis of the " Waste Acids" from the Manufac-
ture of Nitro-Glycerine or Gun-Cotton. — Determine the
specific gravity by the specific gravity bottle or hydrometer,
and the oxides of nitrogen by the permanganate method
described under nitro-glycerine. Now determine the total
acidity of the mixture by means of a tenth normal solution
of sodium hydrate, and calculate it as nitric acid (HNO3),
then determine the nitric acid by means of Lunge nitro-
meter, and subtract percentage found from total acidity,
and calculate the difference into sulphuric acid, thus : —
Total acidity equals 97.46 per cent.— 11.07 Per cent. HNO3
= 86.39 Per cent, then ~^f — -- = 67.20 per cent. H2SO4.
Then analysis of sample will be : —
Sulphuric acid = 67.20 per cent. ^
Nitric acid =11.07 ,, [-Specific gravity = 1.7075.
Water =12.73 » J
This method is accurate enough for general use in the
nitric acid factory. The acid mixture may be taken by
volume for determining nitric oxide in nitrometer. Two
c.c. is a convenient quantity in the above case, then
2x1.7075 (specific gravity) =3.4 1 4 grms. taken, gave 145
c.c. NO (barometer = 748 mm. and temperature = 15° C.)
equals 134.9 c.c. (corr.) and as I c.c. NO = .0282 grm. HNO3
135 x .0282 = .378 grm. = 1 1.07 per cent, nitric acid.
Sodium Nitrate. — Determine moisture and chlorine
by the usual methods, and the total, NaNO3, by mean's of
nitrometer — 0.45 grm. is a very convenient quantity to
work on (gives about 123 c.c. gas); grind very fine, and
dissolve in a very little hot water in the cup of the nitro-
meter ; use about 15 c.c. concentrated H2SO4. One cubic
cent, of NO equals .003805 grm. of NaNO3. The insoluble
240 NlTRO-EXPLOSiVES.
matter, both organic and inorganic, should also be deter-
mined, also sulphate of soda and lime tested for.
Analysis of Mercury Fulminate (Divers and Kawa-
kita's Method). — A weighed quantity of mercury fulminate
is added to excess, but measured quantity of fuming hydro-
chloric acid contained in a retort connected with a receiver
holding water. After heating for some time, the contents
of the retort and receiver are mixed and diluted, and the
mercury is precipitated by hydrogen sulphide. By warming
and exposure to the air in open vessels the hydrogen
sulphide is for the most part dissipated. The solution is
then titrated with potassium hydroxide (KOH), as well as
another quantity of hydrochloric acid, equal to that used
with the fulminate. As the mercury chloride is reconverted
into hydrochloric acid by the hydrogen sulphide, and as
the hydroxylamine does not neutralise to litmus the
hydrochloric acid combined with it, there is an equal
amount of hydrochloric acid free or available in the two
solutions. Any excess of acid in the one which has received
the fulminate will therefore be due to the formic acid
generated from the fulminate. Dr Divers and M. Kawakita,
working by this method, have obtained 31.31 per cent,
formic acid, instead of 32.40 required by theory. (Jour.
C/iem. Soc., p. 17, 1884.)
Divers and Kawakita proceed thus: 2.351 grms. dis-
solved, as already described, in HC1, and afterwards diluted,
gave mercury sulphide equal to 70.40 per cent, mercury.
The same solution, after removal of mercury, titrated by
iodine for hydroxylamine, gave nitrogen equal to 9.85 per
cent., and when evaporated with hydroxyl ammonium
chloride equal to 9.55 per cent. A solution of 2.6665 grms.
fulminate in HC1 of known amount, after removal of
mercury by hydrogen sulphide, gave by titration with
potassium hydrate, formic acid equal to 8.17 per cent, of
carbon, Collecting and comparing with calculation from
formula we get —
ANALYSIS OF CAP COMPOSITION. 241
Calc. I. II. III.
Mercury - 70.42 70.40
Nitrogen - 9.86 9.85 9.55
Carbon 8.45 ... ... 8.17
Oxygen 11.27
IOO.OO
The Analysis of Cap Composition. — Messrs F. W.
Jones and F. A. Willcox (Chem. News, Dec. 1*1, 1896) have
proposed the following process for the analysis of this
substance : — Cap composition usually consists of the in-
gredients— potassium chlorate, antimony sulphide, and
mercury fulminate, and to estimate these substances in the
presence of each other by ordinary analytical methods is a
difficult process. Since the separation of antimony sulphide
and mercury fulminate in the presence of potassium chlorate
necessitates the treatment of the mixture with hydrochloric
acid, and this produces an evolution of hydrogen sulphide
from the sulphide, and a consequent precipitation of sulphur ;
and potassium chlorate cannot be separated from the other
ingredients by treatment with water, owing to the appreci-
able solubility of mercury fulminate in cold water.
In the course of some experiments on the solubility of
mercury fulminate Messrs Jones and Willcox observed that
this body was readily soluble in acetone and other ethereal
solvents when they were saturated with ammonia gas, and
that chlorate of potash and sulphide of antimony were in-
soluble in pure acetone saturated with ammonia ; these
observations at once afforded a simple method of separating
the three ingredients of cap composition. By employing
this solution of acetone and ammonia an analysis can be
made in a comparatively short time, and yields results of
sufficient accuracy for all technical purposes. The following
are the details of the process : —
A tared filter paper is placed in a funnel to the neck of
which has been fitted a piece of rubber tubing provided
with a clip. The paper is moistened with a solution of
Q
242
NITRO-EXPLOSIVES.
acetone and ammonia, the cap composition is weighed off
directly on to the filter paper and is then covered with the
solution of acetone and ammonia and allowed to stand
thirty-four hours. It is then washed repeatedly with the
same solution until the washings give no coloration with
ammonium sulphide, and afterwards washed with acetone
until washings give no residue on evaporation dried and
weighed. The paper is again put in the funnel and washed
with water until free from potassium chlorate, dried and
weighed.
If c= weight of composition taken,
d= „ „ filter paper,
a= „ after first extraction,
b= „ „ second extraction,
then c+d-a = weight of fulminate,
c+d-a-b= „ „ KC1O3,
b — d — „ „ sulphide of antimony.
The composition should be finely ground in an agate
mortar.
The results of the analysis by this method of two
mixtures of known composition are given below —
A
B
Percentage
Taken.
Percentage
Found.
Percentage
Taken.
Percentage
Found.
Antimony Sulphide -
36.47
36.25
37-34
37.22
Potassium Chlorate -
33-25
33-71
46.03
46.43
Mercury Fulminate -
30.27
30.02
16.61
16.34
Dr H. W. Brownsdon's (Jour. Soc. Chem. Ind.^ xxiv., April
1905) process is as follows : — The cap composition is removed
by squeezing the cap with pliers, while held over a porcelain
basin of about 200 c.c. capacity, and removing the loosened
foil and broken composition by means of a pointed wooden
chip. Composition adhering to the shell or foil is loosened
by alcohol, and washed into the dish by means of alcohol
ANALYSIS OF CAP COMPOSITION. 243
in a small wash bottle. The shell and foil are put to one
side and subsequently weighed when dry. The composition
in the dish is broken down quite fine with a flat-headed
glass rod, and the alcohol evaporated on the water bath
till the residue is moist, but not quite dry, 25 c.c. of water
are then added, and the composition well stirred from the
bottom. After the addition of 0.5 grm. of pure sodium,
thiosulphate, the contents of the dish, is well stirred for two
and a half minutes. One drop of methyl orange is then
N
added, and the solution titrated with -- sulphuric acid,
20
which has been standardised against weighings of 0.05 —
O.I grm. fulminate to which 25 c.c. of water is added in a
porcelain dish, then 0.5 grm. of thiosulphate, and after
stirring for two and a half minutes, titrated with — sulphuric
acid. The small amount of antimony sulphide present does
not interfere with the recognition of the end point. After
titration, the solution is filtered through a small 5^ cm.
filter paper, which retains the antimony sulphide. The
filter paper containing the Sb2S3 is well washed and then
transferred to a large 6 by I test tube. Five c.c. of strong
hydrochloric acid are added, and the contents of the tube
boiled gently for a few seconds until the sulphide is dissolved
and all the H2S driven off or decomposed : 2-3 c.c. of a
saturated solution of tartaric acid are added, and the con-
tents of the tube washed into a 250 c.c. Erlenmeyer flask.
The solution is then nearly neutralised with sodium carbon-
ate, excess of bi-carbonate added, and after the addition of
N
some starch solution titrated with — iodine solution. This
20
method for small quantities of stibnite is both quick and
accurate, the error being about ± 0.0003 grm. Sb2S3 at
the outside.
The tendency of this method is to give slightly low
figures for the fulminate, but since these are uniform within
a negligible error, it does not affect the value of the results
244
NITRO-EXPLOSIVES.
as a criterion of uniformity. The following test results
were obtained by Dr Brownsdon : —
Fulminate Taken.
Fulminate Found.
Error.
Grm.
Grm.
Grm.
0.0086
0.0082
0.0074
0.0068
0.0083
O.OoSl
0.0071
0.0066
- 0.0003
— 0.0001
— 0.0003
-O.OOO2
Stibnite Taken.
Sb,,S3 Found.
Error.
Grm.
Grm.
Grm.
0.0085
0.0098
0.0 1 60
0.0099
0.0084
0.0099
0.0157
0.0 1 00
-0.0001
+ 0.0001
— O.OOO3
+ 0.0001
TABLE FOR CORRECTION OF VOLUMES OF GASES FOR TEMPERA-
TURE, GIVING THE DIVISOR FOR THE FORMULA.
VxB
V,=-
(8=0.003665)
76ox(i+S/).
i + 6V from o° to 30° C.
t.
760 x (i + 6V).
<•
76ox(i+8V).
/.
76ox(i+5/).
•c.
0.0
760.000
°c.
1.7
764-7352
°c.
3.4
769.4704
.1
760.2785
.8
765.0137
•5
769.7489
.2
760.5571
•9
765.2923
.6
770.0274
-3
760.8356
2.O
765-5708
• 7
770.3060
•4
761.1142
. I
765-8493
.8
770.5845
761.3927
.2
766.1279
•9
770.8631
.6
761.6712
•3
766.4064
4.0
771.1416
• 7
761.9498
•4
766.6850
.1
771.4201
.8
762.2283
•5
766.9635
.2
771.6987
•9
762.5069
.6
767.2420
•3
771.9772
I.O
762.7854
•7
767.5206
•4
772-2558
. i
763.0639
.8
767.7991
•5
772-5343
.2
763-3425
•9
768.0777
.6
772.8128
•3
763.6210
3-°
768.3562
•7
773.0914
•4
763.8996
.1
768.6347
.8
773-3699
•5
764.1781
.2
768.9133
•9
773-6485
.6
764.4566
• 3
769.1918
1
5-0
773.9270
CORRECTING VOLUMES OF GASES. 245
TABLE FOR CORRECTION OF VOLUMES OF GASES — Continued.
t.
76ox(i+8/).
t.
760 x (1+8*).
/.
760 x (i + &).
°c.
.1
774-2055
°c.
.9
787-5755
°c.
.7
800.9454
.2
774.4841
10.0
787.8540
.8
801.2239
•3
774.7626
.1
788.1325
•9
801.5025
•4
775.0412
.2
788.4111
15.0
801.7810
•5
775-3I97
• 3
788.6896
.1
802.0595
.6
775-59*2
.4
788.9682
.2
802.3381
•7
775-8768
.5
789.2467
• 3
802.6166
.8
776.1553
.6
789-5252
•4
802.8952
•9
776.4339
• 7
789.8038
• 5
803.1737
6.0
776.7124
.8
790.0823
.6
803.4522
.1
776.9909
•9
790.3609
• 7
803.7308
.2
777.2695
II. 0
790.6394
.8
804.0093
•3
777-548o
.1
790.9179
.9
804.2879
•4
777.8266
.2
791.1965
16.0
804.5664
•5
778.1051
•3
791.4750
.1
804.8449
.6
778.3836
•4
791-7536
.2
805.1235
• 7
778.6622
• 5
792.0321
• 3
805.4020
.8
778.9407
.6
792.3106
•4
805.6806
•9
779-2193
• 7
792.5892
•5
805.959I
7.0
779.4978
.8
792.8677
.6
806.2376
. i
779.7763
•9
793-1463
.7
806.5162
.2
780.0549
12.0
793.4248
.8
806.7947
•3
780.3334
.1
793.7033
•9
807.0733
•4
780.6120
.2
793.9819
17.0
807.3518
•5
780.8905
•3
794.2604
.1
807.6303
.6
781.1690
•4
794-5390
.2
807.9089
•7
781.4476
-5
794.8175
• 3
808.1874
.8
781.7261
.6
795.0960
•4
808.4660
•9
782.0047
• 7
795.3746
-5
808.7445
8.0
782.2832
.8
795.6531
.6
809.0230
.1
782.5617
-9
795.9317
-7
809.3016
.2
782.8403
13.0
796.2102
.8
809.580!
•3
783.1188
.1
796.4887
•9
809.8587
•4
783-3974
.2
796.7673
18.0
810.1372
•5
783-6959
•3
797.0458
.1
810.4175
.6
783.9544
•4
797.3244
.2
810.6943
•7
784.2330
-5
797.6029 .3
810.9728
.8
784-5115
.6
797.8814 .4
8II.25I4
•9
784.7901
• 7
798.1600 .5
811.5299
9.0
785.0686
.8
798.4385 .6
8ll.8o84
.1
785-3471
•9
798.7171 .7
812.0870
.2
785.6257
14.0
798.9956 .8
812.3655
•3
785.9042
. i
799.2741 .9
812.644!
•4
786.1828
.2
799.5527 i9-o
812.9226
•5
786.4613
•3
799.8312 .1
8I3.20II
.6
786.7398
•4
800.1098 .2
8I3-4797
• 7
787.0184
-5
800.3883 -3
813.7582
.8
787.2969
.6
800.6668 .4
814.0368
246 NITRO-EXPLOSIVES.
TABLE FOR CORRECTION OF VOLUMES OF GASES — Continued*
t.
760 x (i +&)•
t.
760 x (i + SO-
t.
76ox(i+S/).
•c.
-5
•c.
814.3153 i 23.0
824.0642
•c.
.5
833-8131
.6
814.5938 .1
824.3427
.6
834.0916
.7
814.8724 .2
824.6213
.7
834.3702
.8
815.1500 .3
824.8998
.8
834-6487
• 9
815.4925 .4
825.1784
•9
834.9273
20.0
815.7080 .5
825.4569
27.0
835.2058
.1
815.9865
.6
825.7354
835-4843
.2
816.2651
• 7
826.0140
.2
835.7629
• 3
816.5436
.8
826.2925
•3
836.0414
•4
8l6.8222
•9
826.5711
•4
836.3200
•5
8I7.I007
24.0
826.8496
• 5
836.5985
.6
817.3792
.1
827.1281
.6
836.8770
.7
817.6578
.2
827.4067
.7
8"37-i556
.8
817.9363
•3
827.6852
.8
837.4341
•9
818.2149
•4
827.9638
.9
837.7127
21. 0
818.4934
• 5
828.2423
28.0
837.9912
.1
818.7719
.6
828.5208
.1
838.2697
.2
819.0505
• 7
828.7994
.2
838.5483
•3
819.3290
.8
829.0779
•3
838.8268
•4
819.6076
•9
829-3565
•4
839.1054
•5
8l9.886l
25.0
829.6350
• 5
839-3839
.6
820.1646
.1
829.9135
.6
839.6624
• 7
820.4432
.2
830.1921
• 7
839.9410
.8
820.7217 .3
830.4706
.8
840.2195
•9
821.0003 .4
830.7492
•9
840.4981
22.0
821.2788 .5
831.0277
29.0
840.7766
.1
821.5573 .6
831.3062
. i
841.0551
.2
821.8859 .7
831*5848
.2
84I-3337
•3
822.1144 .8
831.8633 .3
841.6122
•4
822.3930 .9
832.1419 .4
841.8908
•5
822.6715 26.0
832.4204 .5
842.1693
.6
822.9500 .1
832.6989 .6
842.4478
•7
823.2286 .2
832.9775 -7
842.7264
.8
823.5071 .3
833.2560
.8
843.0049
•9
823.7857 .4
833-5346
.9 i 843.2835
II
i 30.0 ! 843.5620
CHAPTER VIII.
FIRING POINT OF EXPLOSIVES,
HEAT TESTS, &c.
Horsley's Apparatus — Table of Firing points — The Government Heat- Test
Apparatus for Dynamites — Nitro-Glycerine, Nitro-Cotton, and Smokeless
Powders — Liquefaction and Exudation Tests — Page's Regulator for Heat-
Test Apparatus — Specific Gravities of Explosives — Table of Temperature
of Detonation, Sensitiveness, &c.
The Firing Point of Explosives. — The firing point of
an explosive may be determined as follows : — A copper
dish, about 3 inches deep, and 6 or more wide, and fitted
with a lid, also of copper, is required. 'The lid contains
several small holes, into each of which is soldered a thick
copper tube about 5 mm. in diameter, and 3 inches long,
with a rather larger one in the centre in which to place a
thermometer. The dish is rilled with Rose's metal, or
paraffin, according to the probable temperature required.
The firing point is then taken thus : — After putting a little
piece of asbestos felt at the bottom of the centre tube, the
thermometer is inserted, and a small quantity of the ex-
plosive to be tested is placed in the other holes ; the lid is
then placed on the dish containing the melted paraffin or
metal, in such a way that the copper tubes dip below the
surface of the liquid ; the temperature of the bath is now
raised until the explosive fires, and the temperature noted.
The initial temperature should also be noted.
248
NITRO-EXPLOSIVES.
THE FIRING POINT OF VARIOUS EXPLOSIVES (by C. E. Munroe).
(Horsley's Apparatus used.)
Nitro-glycerine, 5 years old\
(a single drop taken) - /
203-205
Gun-cotton (compressed mili-\
tary cotton, sp. gr. 1.5) - /
Air-dried gun-cotton, stored\
for 4 years - - - /
192-201
179-187
Ditto, stored for I year
187-189
Air - dried collodion - cotton, ^j
long staple " Red Island j-
186-191
cotton," 3 years old - - j
Air-dried collodion, 3 years \
old, stored wet - - /
197-199
Hydro-nitro-cellulose -
201-213
Kieselguhr dynamite, No. I -
197-200
Explosive gelatine
203-209
Mercury fulminate
175-181
Gunpowder (shell)
278-287
Been in store 10 years. Com-
posed of —
Hill's picric powder (shells) -
Ditto (musket)
273-283
282-290
Ammonium picrate - 42. i8°/0
Potassium picrate - 53-79 ,,
Charcoal (alder) - 3.85 ,,
Forcite, No. I - - -
187-200
99.82%
Atlas powder (75 °/0 NG)
175-185
{Sample had been stored in
Emmensite, No. I
167-184
magazine for some months in
wooden box.
No. 2
165-177
Stored in tin case.
No. 5
205-217
"
Powder used in Chassepot\
rifle - - - - /
191
By Leygue & Champion.
French gunpowder
295
>5 >»
Rifle powder (picrate) -
358
,, ,,
Cannon •••:••
38o
» j »
Horsley's apparatus consists of an iron stand with a
ring support, holding a hemispherical iron vessel or bath in
which solid paraffin is put. Above this is another movable
support, from which a thermometer is suspended, and so
adjusted that its bulb is immersed in the material con-
tained in the iron vessel. A thin copper cartridge-case,
I inch in diameter and ijf inch long, is suspended over the
bath by means of a triangle, so that the end of the case is
ABEL'S HEAT TEST.
249
just I inch below the surface of the molten material. On
beginning the experiment of determining the firing point
of any explosive, the material in the bath is heated to just
above the melting point ; the thermometer is inserted in it,
and a minute quantity of the explosive is placed in the
bottom of the cartridge-case. The initial temperature is
noted, and then the cartridge-case containing the explosive
is inserted in the bath. The temperature is quickly raised
FIG. 46. — HEAT TEST APPARATUS.
until the contents of the cartridge-case flash off or explode,
when the temperature is noted as the firing point.
Professor C. E. Munroe, of the U.S. Torpedo Station,
has determined the firing point of several explosives by
means of this apparatus.
The Government Heat Test (Explosives Act, 1875) :
Apparatus required. — A water bath, consisting of a spheri-
cal copper vessel (<?), Fig. 46, of about 8 inches diameter,
and with an aperture of about 5 inches ; the bath is filled
with water to within a quarter of an inch of the edge. It
/ ' HE
I UNIVERSITY
250 NITRO-EXPLOSIVES.
has a loose cover of sheet copper about 6 inches in diameter
(£), and rests on a tripod stand about 14 inches high (c\
which is covered with coarse wire gauze (e), and is sur-
rounded with a screen of thin sheet copper (d}. Within
the latter is placed an argand burner (/) with glass
chimney. The cover (b) has four holes arranged, as seen
in Fig. II., No. 4 to contain a Page's* or Scheibler's
regulator, No. 3 the thermometer, Nos. I and 2 the test
tubes containing the explosive to be tested. Around the
holes i and 2 on the under side of the cover are soldered
three pieces of brass wire with points slightly converging
(Fig. III.) ; these act as springs, and allow the test tubes to
be easily placed in position and removed.
Test Tubes, from 5] to 5| inches long, and of such a
diameter that they will hold from 20 to 22 cubic centimetres
of water when filled to a height of 5 inches ; rather thick
glass is preferable. Indiarubber stoppers, fitting the test
tubes, and carrying an arrangement for holding the test
papers, viz., a narrow glass tube passing through the centre
of the stopper, and terminating in a platinum wire hook.
A glass rod drawn out and the end turned up to form a
hook is better.
The Thermometer should have a range from 30° to
212° F., or from i° to 100° C. A minute clock is useful.
Test Paper. — The test paper is prepared as follows : —
45 grains (2.9 grms.) of white maize starch (corn flour),
previously washed with cold water, are added to 8J oz. of
water. The mixture is stirred, heated to boiling, and kept
gently boiling for ten minutes; 15 grains (i grm.) of pure
potassium iodide (previously recrystallised from alcohol,
absolutely necessary) are dissolved in Si oz. of distilled
water. The two solutions are thoroughly mixed and
* See Chetn. Soc. Jour., 1876, i. 24. F. J. M. Page.
HEAT TEST. 251
allowed to get cold. Strips or sheets of white English
filter paper, previously washed with water and re-dried, are
dipped into the solution thus prepared, and allowed to
remain in it for not less than ten seconds ; they are then
allowed to drain and dry in a place free from laboratory
fumes and dust. The upper and lower margins of the
strips or sheets are cut off, and the paper is preserved in
well-stoppered or corked bottles, and in the dark. The
dimensions of the pieces of test paper used are about
r4o inch by •& inch (10 mm. by 20 mm.).*
In Germany zinc-iodide starch paper is used, which is
considered to be more sensitive than potassium iodide.
Standard Tint Paper. — A solution of caramel in
water is made of such concentration that when diluted
one hundred times (10 c.c. made up to I litre) the tint of
this diluted solution equals the tint produced by the Nessler
test in 100 c.c. water containing .000075 grm. of ammonia,
or .00023505 grm. Am Cl. With this caramel solution
lines are drawn on strips of white filter paper (previously
well washed with distilled water, to remove traces of
bleaching matter, and dried) by means of a quill pen.
When the marks thus produced are dry, the paper is cut
into pieces of the same size as the test paper previously
described, in such a way that each piece has a brown line
across it near the middle of its length, and only such strips
are preserved in which the brown line has a breadth varying
from J mm. to I mm. (-V of an inch to ^ of an inch).
Testing Dynamite, Blasting- Gelatine, and Gelatine
Dynamite. — Nitro-glycerine preparations, from which the
nitro-glycerine can be extracted in the manner described
* When the paper is freshly prepared, and as long as it remains
in good condition, a drop of diluted acetic acid put on the paper with
a glass rod produces no coloration. In process of time it will become
brownish, when treated with the acid, especially if it has been exposed
to sunlight. It is then not fit for use.
252
NITRO-EXPLOSIVES.
below, must satisfy the following test, otherwise they will
not be considered as manufactured with " thoroughly puri-
fied nitro-glycerine," viz., fifteen minutes at 160° F. (72° C).
Apparatus required. — A funnel 2 inches across (d\ a
cylindrical measure divided into grains (<?), Fig. 47.
Mode of Operation, — About 300 (19.4 grms.) to 400
grains (26 grms.) of dynamite (b\ finely divided, are
placed in the funnel, which is loosely plugged by freshly
ignited asbestos (a). The surface is smoothed by means
of a flat-headed glass rod or stopper, and some clean
FIG. 47. — APPARATUS
FOR SEPARATING THE
NITRO-GLYCERINE
FROM DYNAMITE.
FIG. 48. — TEST
TUBE ARRANGED
FOR HEAT TEST.
washed and dried kieselguhr (c) is spread over it to the
depth of about -J inch. Water is then poured on from a
wash bottle, and when the first portion has been soaked
up more is added ; this is repeated until sufficient nitro-
glycerine has collected in the graduated measure (e}. If
any water should have passed through, it must be removed
from the nitro-glycerine by filter paper, or the nitro-
glycerine may be filtered.
Application of Test. — The thermometer is fixed so as
HEAT TEST — GELATINES, ETC. 253
to be inserted through the lid of the water bath into the
water, which is maintained at 160° F. (72° C.), to a depth
of 2-f inches. Fifty grains ( = 3.29 grms.) of nitro-glycerine
to be tested are weighed into the test tube, in such a way
as not to soil the sides of the tube (use a pipette). A test
paper is fixed on the hook of the glass rod, so that when
inserted into the tube it will be in a vertical position. A
sufficient amount of a mixture of half distilled water and
half glycerine, to moisten the upper half of the paper, is
now applied to the upper edge of the test paper by means
of a glass rod or camel's hair pencil ; the cork carrying the
rod and paper is fixed into the test tube, and the position
of the paper adjusted so that its lower edge is about half
way down the tube ; the latter is then inserted through one
of the holes in the cover to such a depth that the lower
margin of the moistened part of the paper is about f inch
above the surface cover. The test is complete when the
faint brown line, which after a time makes its appearance
at the line of boundary between the dry and moist part of
the paper, equals in tint the brown line of the standard
tint paper.
Blasting Gelatine, Gelatine Dynamite, Gelignite,
&C. — Fifty grains ( = 3.29 grms.) of blasting gelatine are
intimately mixed with 100 grains ( = 6.5 grms.) of French
chalk. This is done by carefully working the two materials
together with a wooden pestle in a wooden mortar. The
mixture is then gradually introduced into the test tube,
with the aid of gentle tapping upon the table between the
introduction of successive portions of the mixture into the
tube, so that when the tube contains all the mixture it shall
be filled to the extent of if inch of its height. The test
paper is then inserted as above described for nitro-glycerine.
The sample tested must stand a temperature of 160° F. for
a period of ten minutes before producing a discoloration
of the test paper corresponding in tint to the standard
paper.
254 NITRO-EXPLOSIVES.
N.B. — Non- gelatinised nitro- glycerine preparations,
from which the nitro-glycerine cannot be expelled by
water, are tested without any previous separation of the
ingredients, the temperature being as above 160° F., and
the time being seven minutes.
Gun-Cotton, Schultze Gunpowder, E.G. Powder,
&c. : A. Compressed Gun-Cotton. — Sufficient material to
serve for two or more tests is removed from the centre of
the cartridge by gentle scraping, and if necessary, further
reduced by rubbing between the fingers. The fine powder
thus produced is spread out in a thin layer upon a paper
tray 6 inches by 4^ inches, which is then placed inside a
water oven, kept as nearly as possible at 120° F. (49° C.).
The wire gauze shelves of the oven should be about 3 inches
apart. The sample is allowed to remain at rest for fifteen
minutes in the oven, the door of which is left wide open.
After the lapse of fifteen minutes the tray is removed and
exposed to the air of the room for two hours, the sample
being at some point within that time rubbed upon the tray
with the hand, in order to reduce it to a fine and uniform
state of division.
The heat test is performed as before, except that the
temperature of the bath is kept at 170° F. (66° C.), and
regulator set to maintain that temperature. Twenty grains
(1.296 grm.) are used, placedi n the test tube, gently pressed
down until it occupies a space of as nearly as possible
lyV inch in the test tube of dimensions previously speci-
fied. The fine cotton adhering to the sides of the tube can
be removed by a clean cloth or silk handkerchief. The
paper is moistened by touching the upper edge with a drop
of the 50 per cent, glycerine solution, the tube inserted in
the bath to a depth of 2j inches, measured from the cover,
the regulator and thermometer being inserted to the same
depth. The test paper is to be kept near the top of the test
tube, but clear of the cork, until the tube has been immersed
for about five minutes. A ring of moisture will about this
HEAT TEST — CORDITE, SCHULTZE, ETC. 255
time be deposited upon the sides of the test tube, a little
above the cover of the bath. The glass rod must then be
lowered until the lower margin of the moistened part of the
paper is on a level with the bottom of the ring of moisture
in the tube. The paper is now closely watched. The test
is complete when a very faint brown coloration makes its
appearance at the line of boundary between the dry and
moist parts of the paper. It must stand the test for not
less than ten minutes at 170° F. (The time is reckoned from
the first insertion of the tube in the bath until the appear-
ance of a discoloration of the test paper.)
B. Schultze Powder, E.G. Powder, Collodion-
Cotton, &c. — The sample is dried in the oven as above for
fifteen minutes, and exposed for two hours to the air. The
test as above for compressed gun-cotton is then applied.
C. Cordite must stand a temperature of 180° F. for
fifteen minutes. The sample is prepared as follows : —
Pieces half an inch long are cut from one end of every
stick selected for the test : in the case of the thicker
cordites, each piece so cut is further subdivided into about
four portions. These cut pieces are then passed once
through the mill, the first portion of material which passes
through being rejected on account of the possible presence
of foreign matter from the mill. The ground material is
put on the top sieve of the nest of sieves, and sifted. That
portion which has passed through the top sieve and been
stopped by the second is taken for the test. If the mill is
properly set, the greater portion of the ground material will
be of the proper size. If the volatile matter in the explosive
exceeds 0.5 per cent., the sifted material should be dried at
a temperature not exceeding 140° F., until the proportion
does not exceed 0.5 per cent. After each sample has been
ground, the mill must be taken to pieces and carefully
cleaned. The sieves used consist of a nest of two sieves
with holes drilled in sheet copper. The holes in the top
256 NITRO-EXPLOSIVES.
sieve have a diameter = 14 B.W.G., those in the second
= 21 B.W.G.
If too hard for the mill, the cordite may be softened
by exposure to the vapour of acetone,* or reduced to the
necessary degree of subdivision by means of a sharp
moderately-coarse rasp. Should it have become too soft
in the acetone vapour for the mill, it should be cut up into
small pieces, which may be brought to any desired degree
of hardness by simple exposure to air. Explosives which
consist partly of gelatinised collodion-cotton, and partly of
ungelatinised gun-cotton, are best reduced to powder by a
rasp, or softened by exposure to mixed ether and alcohol
vapour at a temperature of 40° F. to 100° F.
Ballistite. — In the case of ballistite the treatment is
the same, except that when it is in a very finely granulated
condition it need not be cut up.
Guttmann's Heat Test. — This test was proposed by
Mr Oscar Guttmann in a paper read before the Society of
Chemical Industry (vol. xvi., 1897), in the place of the
potassium iodide starch paper used in the Abel test. The
filter paper used is wetted with a solution of diphenylamine f
in sulphuric acid. The solution is prepared as follows: —
Take o.ioo grm. of diphenylamine crystals, put them in a
wide-necked flask with a ground stopper, add 50 c.c. of
dilute sulphuric acid (10 c.c. of concentrated sulphuric acid
to 40 c.c. of water), and put the flask in a water bath at
between 50° and 55° C. At this temperature the diphenyl-
* Mr W. Cullen (Jour. Soc. Chem. Ind., Jan. 31, 1901) says: —
" Undoubtedly the advent of the horny smokeless powders of modern
times has made it a little difficult to give the test the same scope as it
had when first introduced?' As a rule a simple explanation can be
found for every apparently abnormal result, and in the accidental
retention of a portion of the solvent used in the manufacture, will
frequently be found an explanation of the trouble experienced.
t Dr G. Spica (Rhrista, Aug. 1897) proposes to use hydrochloride
of meta-phenylenediamine.
EXUDATION AND LIQUEFACTION TEST. 257
amine will melt, and at once dissolve in the sulphuric acid,
when the flask should be taken out, well shaken, and
allowed to cool. After cooling, add 50 c.c. of Price's
double distilled glycerine, shake well, and keep the solution
in a dark place. The test has to be applied in the follow-
ing way : — The explosives that have to be tested are finely
subdivided, gun-cotton, nitro-glycerine, dynamite, blasting
gelatine, &c., in the same way as at present directed by the
Home Office regulations. Smokeless powders are all to
be ground in a bell-shaped coffee mill as finely as possible,
and sifted as hitherto. 1.5 grm. of the explosive (from
the second sieve in the case of smokeless powder) is to be
weighed off and put into a test tube as hitherto used.
Strips of well-washed filter paper, 25 mm. wide, are. to
be hung on a hooked glass rod as usual. A drop of the
diphenylamine solution is taken up by means of a clean
glass rod, and the upper corners of the filter paper are
touched with it, so that when the two drops run together
about a quarter of the filter paper is moist. This is then
put into the test tube, and this again into the water bath,
which has been heated to 70° C. The heat test reaction
should not show in a shorter time than fifteen minutes. It
will begin by the moist part of the paper acquiring a
greenish yellow colour, and from this moment the paper
should be carefully watched. After one or two minutes a
dark blue mark will suddenly appear on the dividing line
between the wet and dry part of the filter paper, and this
is the point that should be taken.
Exudation and Liquefaction Test for Blasting
Gelatine, Gelatine Dynamite, &c. — A cylinder of blasting
gelatine, &c., is to be cut from the cartridge to be tested,
the length of the cylinder to be equal to its diameter, and
the ends being cut flat. The cylinder is to be placed on
end on a flat surface without any wrapper, and secured by
a pin passing vertically through its centre. In this condi-
tion the cylinder is to be exposed for 144 consecutive hours
R
258 NITRO-EXPLOSIVES.
(six days and nights) to a temperature ranging from 85° to
90° F. (inclusive), and during such exposure the cylinder
shall not diminish in height by more than one-fourth of its
original height, and the upper cut surface shall retain its
flatness and the sharpness of its edge.
Exudation Test. — There shall be no separation from
the general mass of the blasting gelatine or gelatine dyna-
mite of a substance of less consistency than the bulk of the
remaining portion of the material under any conditions of
storage, transport, or use, or when the material is subjected
three times in succession to alternate freezing and thawing,
or when subjected to the liquefaction test before described.
Picric Acid. — The material shall contain not more
than 0.3 part of mineral or non-combustible matter in 100
parts by weight of the material dried at 160° F. It should
not contain more than a minute trace of lead. One hundred
parts of the dry material shall not contain more than 0.3
part of total (free and combined) sulphuric acid, of which
not more than o.i part shall be free sulphuric acid. Its
melting point should be between 248° and 253° F.
Ammonite, Bellite, Roburite, and Explosives of
similar Composition. — These are required to stand the
same heat test as compressed nitro-cellulose, gun-cotton,
&c.
Chlorate Mixtures. — The material must not be too
sensitive, and must show no tendency to increase in sens
tiveness in keeping. It must contain nothing liable to
reduce the chlorate. Chlorides calculated as potassium
chloride must not exceed 0.25 per cent. The material
must contain no free acid, or substance liable to produce
free acid. Explosives of this class containing nitro-com-
pounds will be subject to the heat test.
PAGE REGULATOR. 259
Page's Regulator. — The most convenient gas regulator
to use in connection with the heat-test apparatus is the one
invented by Prof. F. J. M. Page, B.Sc.* (Fig. 49). It is not
affected by variations of the barometric pressure, and is
simple and easy to fit up. It consists of a thermometer
with an elongated glass bulb f inch diameter and 3 inches
long. The stem of the thermometer is 5 inches long and
£ inch to y\ inch internal diameter. One and a half inch
from the top of the stem is fused in at right angles a piece
of glass tube, I inch long, of the same diameter as the stem,
so as to form a T. A piece of glass tube (A), about ~ inch
external diameter and ij inch long, is fitted at one end
with a short, sound cork (c, Fig. 50). Through the centre
of this cork a hole is bored, so that the stem of the ther-
mometer just fits into it. The other end of this glass tube
is closed by a tightly fitting cork, preferably of indiarubber
(i), which is pierced by a fine bradawl through the centre.
Into the hole thus made is forced a piece of fine glass tube
(B) 3 inches long, and small enough to fit loosely inside the
stem of the thermometer.
The thermometer is filled by pouring in mercury through
a small funnel until the level of the mercury (when the
thermometer is at the desired temperature) is about i|
inch below the T. The piece of glass tube A, closed at
its upper extremity by the cork I, through which the fine
glass tube B passes into the stem of the thermometer, is
now filled by means of the perforated cork at its lower
extremity on the stem of the thermometer. The gas
supply tube is attached to the top of the tube A, the burner
to the T, so that the gas passes in at the top, down the fine
tube B, rises in the space between B and the inside wall of
the stem of the thermometer, and escapes by the T. The
regulator is set for any given temperature by pushing the
cork C, and consequently the tubes A and B, which are
firmly attached to it, up or down the stem of the ther-
* Chemical Soc Jour,^ 1876, i. 24.
260
NITRO-EXPLOSIVES.
mometer, until the regulator just cuts off the gas at the
desired temperature.
As soon as the temperature falls, the mercury contracts,
and thus opens the end of the tube B. The gas is thus
turned on, and the temperature rises until the regulator
again cuts off the gas. In order to prevent the possible
extinction of the flame by the regulator, the brass tube
X'T
I
rs
to Burner
FIG. i.
from Gas
Supply
FIG. 2.
FIG. 49. — PAGE'S REGULATOR.
FIG. 50. — PAGE'S GAS REGULATOR, SHOWING
BYE-PASS AND CUT-OFF ARRANGEMENT.
which carries the gas to the regulator is connected with the
tube which brings the gas from the regulator to the burner
by a small brass tap (Fig. 2). This tap forms an adjust-
able bye-pass, and thus a small flame can be kept burning,
even though the regulator be completely shut off. It is
obvious that the quantity of gas supplied through the bye-
pass must always be less than that required to maintain
WILL'S TEST FOR CELLULOSE. 261
the desired temperature. This regulator, placed in a beaker
of water on a tripod, will maintain the temperature of the
water during four or five hours within 0.2° C, and an air
bath during six weeks within 0.5° C.
To sum up briefly the method of using the regulator : —
Being filled with mercury to about J inch below the T,
attach the gas supply as in diagram (Fig. 2), the brass tap
being open, and the tube B unclosed by the mercury.
Allow the gas to completely expel the air in the apparatus.
Push down the tube A so that the end of B is well under
the surface of the mercury. Turn ofif the tap of the bye-
pass until the smallest bead of flame is visible. Raise A
and B, and allow the temperature to rise until the desired
point is attained. Then push the tubes A and B slowly
down until the flame is just shut off. The regulator will
then keep the temperature at that point.
Will's Test for Nitro-Cellulose.— The principle of
Dr W. Will's test * may be briefly described as follows : —
The regularity with which nitro-cellulose decomposes under
conditions admitting of the removal of the products of de-
composition immediately following their formation is a
measure of its stability. As decomposing agent a suffi-
ciently high temperature (135° C.) is employed, the ex-
plosive being kept in a constantly changing atmosphere of
carbon dioxide, heated to the same temperature : the
oxides of nitrogen which result are swept over red-hot
copper, and are then reduced to nitrogen, and finally, the
rates of evolution of nitrogen are measured and compared.
Dr Will considers that the best definition and test of a
stable nitro-cellulose is that it should give off at a high
temperature equal quantities of nitrogen in equal times.
For the purposes of manufacture, it is specially important
that the material should be purified to its limit, i.e., the
point at which further washing produces no further change
* W. Will, Mitt. a. d. Centrallstelle /. Wissench. Techn. Unter-
suchungeu Nuo-Babclsberg Berlin, 1902 [2], 5-24.
262 NITRO-EXPLOSIVES.
in its speed of decomposition measured in the manner
described.
The sample of gun-cotton (2.5 grms.) is packed into the
decomposition tube 15 mm. wide and 10 cm. high, and
heated by an oil bath to a constant temperature, the oxides
so produced are forced over ignited copper, where they are
reduced, and the nitrogen retained in the measuring tubes.
Care must be taken that the acid decomposition products
do not condense in any portion of the apparatus. The air
in the whole apparatus is first displaced by a stream of
carbon dioxide issuing from a carbon dioxide generator, or
gas-holder, and passing through scrubbers, and this stream
of gas is maintained throughout the whole of the experi-
ment, the gas being absorbed at the end of the system by
strong solution of caustic potash. To guard against the
danger of explosions, which occasionally occur, the decom-
position tube and oil bath are surrounded by a large casing
with walls composed of iron plate and strong glass.
Dr Will's apparatus has been modified by Dr Robertson,*
of the Royal Gunpowder Factory, Waltham Abbey. The
form of the apparatus used by him is shown in Fig. 51.
CO2 Holders. — Although objection has been taken
to the use of compressed CO2 in steel cylinders on account
of the alleged large and variable amount of air present, it
has, nevertheless, been found possible to obtain this gas
with as little as 0.02 per cent, of air. Frequent estimations
of the air present in the CO.2 of a cylinder show that even
with the commercial article, after the bulk of the CO2 has
been removed, the residual gas contains only a very small
amount of air, which decreases in a gradual and perfectly
regular manner. For example, one cylinder which gave
0.03 per cent, of air by volume, after three months' constant
use gave 0.0.2 per cent. The advantage of using CO2 from
this source is obvious when compared with the difficulty of
* Jour. Soc. Chem. Ind., June 30, 1902, p. 819.
WILL'S APPARATUS.
263
264 NITRO-EXPLOSIVES.
evolving a stream of gas of constant composition from a
Kipps or Finkener apparatus. A micrometer screw, in
addition to the main valve of the CO2 cylinder, is useful for
governing the rate of flow. A blank experiment should be
made to ascertain the amount of air in the CO2 and the
correction made in the readings afterwards.
Measurement of Pressure and Rate of Flow.—
Great attention is paid to the measurement of the rate of
flow of gas, which is arrived at by counting with a stop-
watch the number of bubbles of gas per minute in a small
sulphuric acid wash bottle. A mercury manometer is intro-
duced here, and is useful for detecting a leak in the
apparatus. The rate of flow that gives the most satisfactory
results is 1,000 c.c. per hour. If too rapid it does not be-
come sufficiently preheated in the glass spiral, and if too
slow there is a more rapid decomposition of the nitro-
cellulose by the oxides of nitrogen which are not removed.
Decomposition Tube. — This is of the form and
dimensions given by Dr Will (15 mm. wide and 10 cm.
high), the preheating worm being of the thinnest hydro-
meter stem tubing. The ground-in exit tube is kept in
position by a small screw clamp with trunnion bearings.
Bath. — To permit of two experiments being carried
on simultaneously, the bath is adapted for two decomposi-
tion tubes, and is on the principle of Lothar Meyer's air
bath, that is, the bath proper filled with a high-flashing
hydrocarbon oil, and fitted with a lid perforated with two
circular holes for the spiral tubes, is surrounded by an
asbestos-covered envelope, in the interior of which circulate
the products of combustion of numerous small gas jets.
The stirrer, agitated by a water motor, or, better still, a
hot-air engine, has a series of helical blades curved to give
a thorough mixing to the oil. Great uniformity and con-
stancy of temperature are thus obtained. The bath is fitted
also with a temperature regulator and thermometer.
WILL'S TEST FOR CELLULOSE. 265
Reduction Tube. — This is of copper, and consists of
,two parts, the outer tube and an inner reaching to nearly the
bottom of the former. Into the inner tube fits a spiral of
reduced copper gauze, and into the annular space between
the tubes is fitted a tightly packed reduced copper spiral.
At the bottom the inlet tube dips into a layer of copper
oxide asbestos, on the top of which is a layer of reduced
copper asbestos. Through the indiarubber cork passes a
glass tube, which leads the CO2 and nitrogen out of the
reduction tube. As the portion of the tube containing the
spirals is heated to redness, water jackets are provided on
both inner and outer tubes to protect the indiarubber cork.
Nitrogen Measuring Apparatus. — The measuring
tube with zigzag arrangement is used, having been found
very economical in potash. It is most convenient to take
readings by counterbalancing the column of potash solution
and reading off the volume of gas at atmospheric pressure.
For this purpose the tap immediately in front of the
measuring tube is momentarily closed, this having been
proved to be without ill effect on the progress of the test.
In all experiments done by this test the air correction is
subtracted from each reading, and the remainder brought
to milligrams of nitrogen with the usual corrections. As
objection has frequently been taken to the test on the
ground of difficulty in interpreting the results obtained,
Dr Robertson made a series of experiments for the purpose
of standardising the test, and at the same time of arriving
at the condition under which it could be applied in the
most sensitive and efficient manner. A variety of nitro-
celluloses having been tested, there were chosen as typical,
of stable and unstable products, service gun-cotton on the
one hand, and an experimental gun-cotton, Z, on the other.
The first point brought out by these experiments was the
striking uniformity of service gun-cotton, first in regard to
the rectilinear nature of the curve of evolution of nitrogen,
and secondly in regard to the small range within which a
266
NITRO-EXPLOSIVES.
large number of results is included, 15 samples lying
between 6.6 and 8.7 mgms. of nitrogen evolved in four
hours. In the case of service gun-cotton, little difference
in the rate of evolution of nitrogen evolved is obtained on
altering the rate of passage of CO2 gas through the wide
range of 500 c.c. per hour to 2,500 c.c. per hour. With Z
gun-cotton (see Fig. 52), however, the case is very different.
Fig. 52
23
22
21
20
19
18
17
16
15
14
13
12
II
10
3
8
7
6
5
4-
3
2
1
Z. Gun-
Cotton
untreated
Service
Guncotton
untreated
Quarter
/
/
/
r
/
^>
f
s*
/
/
/
/
\
/
/
s
1
xl
1
/
/
s
/
/
/
/
^
^
/
^
•^
^
— •-
^
I 2 3 4 5 6 7 6 9 10 II 12 13 14 15 16 Hours
D? Robertson's results.
Operating at a rate of 1,000 c.c. of CO2 per hour, a curve of
nitrogen evolution is obtained, which is bent and forms a
good representation of the inherent instability of the material
as proved to exist from other considerations. Operating at
the rate of 1,500 c.c. per hour, as recommended by Dr Will,
the evolution of nitrogen is represented by a straight line,
steeper, however, than that of service gun-cotton. The rate
of passage of CO2 was therefore chosen at 1,000 c.c. per
CURVES GIVEN BY WILL'S TEST.
267
hour, or two-thirds of the rate of Dr Will, and this rate,
besides possessing the advantage claimed of rendering
diagnostic the manner of nitrogen evolution in Z gun-
cotton, has in other cases been useful in bringing out
relationships, which the higher rate would have entirely
masked.
Readings are taken thirty minutes from the time the
nitro-cellulose is heated, and are taken at intervals of fifteen
minutes for about four hours ; fresh caustic potash is added
every thirty minutes or so. It is convenient to plot the
.Fig. 53
10
Quarter
I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 Hours
Service Guncotton for Cordite made at a Private Factory.
results in curves. The curves given in Fig. 53 are from
gun-cotton manufacturers in England at a private factory.
The rate of evolution of nitrogen is as follows : —
In i hour.
N.
In 2 hours.
N.
In 3 hours. In 4 hours.
N. N. in milligrammes.
1.25 2.55 4-5 5-75
1.5 3.25 5.25 6.75
These results are very satisfactory, the gun-cotton was of
a very good quality. Several hours are necessary to re-
move all the air from the apparatus. Dr Will stated fifteen
minutes in his original paper, but this has not been found
sufficient. It has not been satisfactorily proved that Will's
268 NITRO-EXPLOSIVES.
test can be applied to gelatinised nitrocellulose powders.
It is convenient to plot the results in curves ; the nitrogen
is generally given in cubic centimetres or in milligrammes,
and readings taken every fifteen minutes. The steepness
of the curve is a measure of the stability of the nitro-
cellulose which is being examined. The steeper the curve
the more nitrogen is evolved per unit of time, and the less
stable the nitro-cellulose. In the case of unstable nitro-
celluloses heated under the conditions described, the separa-
tion of nitrogen is much greater at first than at a later
period. If the nitro-cellulose be very unstable, explosions
are produced. If the separation of nitrogen is uniform
during the prolonged heating, then the nitro-cellulose may
be regarded as "normal." If it be desired to determine the
absolute amount of nitrogen separated from a nitro-cellulose,
the following conditions must be observed: — (i.) Accurate
weighing of the nitro-cellulose ; (2.) Determination of the
amount of air in the CO2, and deduction of this from the
volume of gas obtained ; (3.) Reduction of the volume of
the gas to the volume at o° C. and 760 mm. pressure.*
Bergmann and Junkj- describe a test for nitro-
cellulose that has been in use in the Prussian testing station
for some years. The apparatus consists of a closed copper
bath provided with a condenser and 10 countersunk tubes
of 20 cm. length. By boiling amyl-alcohol in the bath, the
tubes can be kept at a constant temperature of 132° C.
The explosive to be tested is placed in a glass tube 35 cm.
long and 2 cm. wide, having a ground neck into which an
absorption bulb is fitted. The whole apparatus is sur-
rounded by a shield, in case of explosion. In carrying out
the test, 2 grms. of the explosive are placed in the glass tube
and well pressed down. The absorption bulb is half filled
* See also Jour. Soc. Chew. /«//., Dec. 1902, pages 1545-1555, on
the "Stability of Nitro-cellulose" and "Examination of Nitro-
cellulose," Dr Will.
t Jour. Soc. Chem. Ind., xxiii., Oct. 15, 1904, p. 953.
BERGMANN AND JUNK'S TEST. 269
with water, and fitted into the ground neck of the glass
tube, which is then placed in one of the tubes in the bath
previously brought to the boiling point (132° C). The
evolved oxides of nitrogen are absorbed in the water in the
bulb, and at the end of two hours the tubes are removed
from the bath, and on cooling, the water from the bulb
flows back and wets the explosive. The contents of the
tube are filtered and washed, the filtrate is oxidised with per-
manganate, and the nitrogen determined as nitric oxide by
the Schultze-Tieman method. The authors conclude that
a stable gun-cotton does not evolve more than 2.5 c.c. of
nitric oxide per grm. on being heated to 132° C. for two
hours, and a stable collodion-cotton not more than 2 c.c.
under the same conditions. The percentage of moisture in
the sample to be tested should be kept as low as possible.
A sample of nitro-cellulose containing 1.97% of moisture
gave an evolution of 2.6 c.c. per grm., while the same sample
with 3.4 % moisture gave an evolution of over 50 c.c. per
grm. Sodium carbonate added to an unstable nitro-
cellulose diminishes the rate of decomposition, but if sodium
carbonate be intimately mixed with a stable nitro-cellulose
the rate of decomposition will be increased. Calcium
carbonate and mercury chloride have no influence. If an
unstable nitro-cellulose be extracted with alcohol a stable
compound is produced. The percentage solubility of a
nitro-cellulose in ether-alcohol rises on heating to 132° C.
A sample which before heating had a solubility of 4.7 °/0
had its solubility increased to 82.57,, after six hours' heating.
Mr A. P. Sy (Jour. Amer. Chem. Soc., 1903) describes a
new stability test for nitro-cellulose which he terms " The
Elastic Limit of Powder Resistance to Heat." The test con-
sists in heating the powder on a watch glass in an oven to
a temperature of 1 1 5 ° C., after eight hours the watch glass
and powder are weighed and the process repeated daily for
six days or less. He claims that the powder is tested in
its natural state, all the products of decomposition are
taken into account, whilst in the old tests only the acid pro-
270 NITRO-EXPLOSIVES.
ducts are shown, and in the Will test only nitrogen, that it
affords an indication of the effect of small quantities of
added substances or foreign matters on the stability and
that it is simple, and not subject to the variations of the
old tests.
Obermiiller (Jour. Soc. Chem. Ind., April 15, 1905)
considers Bergmann and Junk's test is too complicated and
occupies too much time; he proposes to heat gun-cotton to
140° C. in vacuO) and to measure continuously by means of
a mercury manometer the pressure exerted by the evolved
gases, the latter being maintained at constant volume ; the
rate at which the pressure increases is a measure of the rate
of decomposition of the nitro-cellulose.
SPECIFIC GRAVITIES OF EXPLOSIVES, &c.
Nitro-glycerine - .6
Gun-cotton (dry) - .06
„ (25 per cent, water) .32
Dynamite No. I 62
Blasting gelatine .54
Gelatine dynamite .55
Ballistite - .6
Forcite - .51
Tonite - .28
Roburite - .40
Bellite - .2-1.4
Carbo-dynamite 1.5
Turpin's cast picric acid - 1.6
Nitro-mannite - 1.6
Nitro-starch - 1.5
Emmensite 1.8
Mono-nitro-benzene - - - - - 1.2
Meta-di-nitro-benzene - .- , - 1.575 at i8°C.
Ortho-di-nitro-benzene - i-59° •>•>
Para-di-nitro-benzene 1.625 »
British gunpowder, E.X.E. 1.80
S.B.C. 1.85
Cannonite (powder) - 1.60
Celluloid - 1.35
Cellulose - - 1.45
Ammonium nitrate - i-7o?
Mercury fulminate - • .. * 4.42
TEMPERATURE OF DETONATION, ETC.
TABLE OF THE TEMPERATURE OF DETONATION.
271
Blasting gelatine
Nitro-glycerine -
Dynamite
Gun-cotton
Tonite - . -
Picric acid
Roburite -
Ammonia nitrate
3220
3170°
2940°
2650°
2648°
2620°
2100°
II300
RELATIVE SENSITIVENESS TO DETONATION (by Professor C. E.
Munroe, U.S. Naval Torpedo Station).
Maximum Dis-
tance at which
Detonation
occurred.
CM.
Gun-cotton
IO
/Nitro-glycerine 86.5, nitro-cotton
\ 9. 5, camphor 4 per cent.
Explosive gelatine (cam- \
phorated) - - /
20
f NH4NO3 5 parts, C6H4(NO3)2 i
\ part.
Judson powder, R.R.P.
25
Emmensite (No. 259)
30
Rack-a-rock
32
rKC103 79 parts, C6H5(NO)2 21
\ parts.
Bellite
50
Forcite No. I -
61
Kieselguhr dynamite No. I
64
75 per cent, nitro-glycerine.
Atlas powder No. I -
74
CHAPTER IX.
DETERMINATION OF THE RELATIVE
STRENGTH OF EXPLOSIVES.
Effectiveness of an Explosive — High and Low Explosives — Theoretical
Efficiency — MM. Roux and Sarrau's Results — Abel and Noble's —
Nobel's Ballistic Test — The Mortar, Pressure, or Crusher Gauge —
Lead Cylinders — The Foot- Pounds Machine — Noble's Pressure Gauge
— Lieutenant Walke's Results — Calculation of Pressure Developed by
Dynamite and Gun-Cotton — Macnab's and Ristori's Results of Heat
Developed by the Explosion of Various Explosives — Composition of
some of the Explosives in Common Use for Blasting, &c.
The Determination of the Relative Strength of Ex-
plosives.— Explosives may be roughly divided into two
divisions, viz., those which when exploded produce a
shattering force, and those which produce a propulsive
force. Explosives of the first class are generally known as
the high explosives, and consist for the most part of nitro
compounds, or mixtures of nitro compounds with other
substances. Any explosive whose detonation is very rapid
is a high explosive, but the term has chiefly been applied
to the nitro-explosives.
The effectiveness of an explosive depends upon the
volume and temperature of the gases formed, and upon the
rapidity of the explosion. In the high explosives the
chemical transformation is very rapid, hence they exert a
crushing or shattering effect. Gunpowder, on the other
hand, is a low explosive, and produces a propelling or
heaving effect.
The maximum work that an explosive is capable of
producing is proportionate to the amount of heat disen-
MECHANICAL EQUIVALENT OF EXPLOSIVES. 2/3
gaged during its chemical transformation. This may be
expressed in kilogrammetres by the formula 42 5 Q, where
Q is the number of units of heat evolved. The theoreti-
cal efficiency of an explosive cannot, however, be expected
in practice for many reasons.
In the case of blasting rock, for instance : * — i. Incom-
plete combustion of the explosive. 2. Compression and
chemical changes induced in the surrounding material
operated on. 3. Energy expended in the cracking and
heating of the material which is not displaced. 4. The
escape of gas through the blast-hole, and the fissures
caused by the explosion. The proportion of useful work
has been estimated to be from 14 to 33 per cent, of the
theoretical maximum potential.
For the purposes of comparison, manufacturers gene-
rally rely more upon the practical than the theoretical
efficiency of an explosive. These, however, stand in the
same relation to one another, as the following table of
Messrs Roux and Sarrau will show : —
MECHANICAL EQUIVALENT OF EXPLOSIVES.
Theoretical Work Relative
in Kilos. Value.
Blasting powder (62 per cent. KNO3) - - 242,335 i.o
Dynamite (75 per cent, nitro-glycerine) - - 548,250 2.26
Blasting gelatine (92 per cent, nitro-glycerine) - 766,813 3.16
Nitro-glycerine- - - - 794,563 3-28
Experiments made in lead cylinders give —
Dynamite i.o
Blasting gelatine i-4
Nitro-glycerine 1.4
Sir Frederick Abel and Captain W. H. Noble, R.A.,
have shown that the maximum pressure exerted by gun-
powder is equal to 486 foot-tons per Ib. of powder, or
that when I kilo, of the powder gases occupy the volume
of I litre, the pressure is equal to 6,400 atmospheres ; and
* C. N. Hake, Government Inspector of Explosives, Victoria,
Jour. Soc. Chem. Ind., 1889.
S
274 NITRO-EXPLOS1VES.
Berthelot has calculated that every gramme of nitre-glyce-
rine exploded gives 1,320 units of heat. MM. Roux and
Sarrau, of the Depot Centrales des Poudres, Paris, by
means of calorimetric determinations, have shown that
the following units of heat are produced by the detona-
tion of —
Nitro-glycerine - 1,784 heat units,
Gun-cotton 1,123 »
Potassic picrate - 840 „
which, multiplied by the mechanical equivalent per unit,
gives—
Nitro-glycerine - - 778 metre tons per kilogramme.
Gun-cotton - 489 „ „
Picrate of potash - 366 „ „
Nobel's Ballistic Test.— Alfred Nobel was the first
to make use of the mortar test to measure the (ballistic)
power of explosives. The use of the mortar for measur-
ing the relative power of explosives does not give very
accurate results, but at the same time the information
obtained is of considerable value from a practical point
of view. The mortar consists of a solid cylinder of cast
iron, one end of which has been bored to a depth of 9 inches,
the diameter of the bore being 4 inches. At the bottom
of the bore-hole is a steel disc 3 inches thick, in which
another hole has been bored 3 inches by 2 inches. The
mortar (Fig. 54) itself is fitted with trunnions, and firmly
fixed in a very solid wooden carriage, which is securely
bolted down to the ground. The shot used should weigh
28 Ibs., and be turned accurately to fit the bore of the
mortar. Down its centre is a hole through which the
fuse is put.
The following is the method of making an experi-
ment : — A piece of hard wood is turned in the lathe to
exactly fit the hole in the steel disc at the bottom of the
bore. This wooden cylinder itself contains a small cavity
into which the explosive is put. Ten grms. is a. very
convenient quantity. Before placing in the mortar, a
MORTAR TEST FOR EXPLOSIVES.
275
hole may be made in the explosive by means of a piece
of glass rod of such a size that the detonator to be used
will just fit into it. After placing the wooden cylinder
containing the explosive in the cavity at the bottom
of the bore, the shot, slightly oiled, is allowed to fall
gently clown on to it. A piece of fuse about a foot long,
and fitted with a detonator, is now pushed through the
hole in the centre of the shot until the detonator is
embedded in the explosive. The fuse is now lighted, and
m
FlG. 54. — MOKTAR FOR MEASURING THE BALLISTIC POWER OF EXPLOSIVES.
A, Shot; B, Steel Disc; C, Section of Mortar (Cast Iron); D, Wooden Plug holding
Explosive (£); f, Fuse.
the distance to which the shot is thrown is carefully
measured. The range should be marked out with pegs
into yards and fractions of yards, especially at the end
opposite to the mortar. The mortar should be inclined
at an angle of 45°. In experimenting with this apparatus,
the force and direction of the wind will be found to have
considerable influence.
Mr T. Johnson made some ballistic tests. He used a
steel mortar and a shot weighing 29 Ibs., and he adopted
the plan of measuring the distance to which a given charge,
5 grms., would throw the shot. He obtained the following
results : —
2/6 NITRO-EXPLOSIVES.
Range in Feet.
Blasting gelatine (90 per cent, nitro-glycerine and nitro-
cellulose) 392
Ammonite (60 per cent. Am(NO3) and 10 per cent, nitro-
naphthalene) 310
Gelignite (60 per cent, nitro-gelatine and gun-cotton) 306
Roburite (AmNO3 and chloro-nitro-benzol) - 294
No. i dynamite (75 per cent, nitro-gelatine) - - 264
Stonite (68 per cent, nitro-gelatine and 32 per cent.
wood- meal) - 253
Gun-cotton - - 234
Tonite (gun-cotton and nitrates) - 223
Carbonite (25 per cent, nitro-gelatine, 40 per cent, wood-
meal, and 30 per cent, nitrates) - 198
Securite (KNO3 and nitro-benzol) - 183
Gunpowder - 143
Calculation of the Volume of Gas Evolved in an
Explosive Reaction. — The volume of gas evolved in an
explosive reaction may be calculated, but only when they
are simple and stable products, such calculations being
made at o° and 760 mm. Let it be required, for example,
to determine the volume of gas evolved by I gram-
molecule of nitro-glycerine. The explosive reaction of
nitro-glycerine may be represented by the equation.
C3H503( N02)3 = 3C02 + 2iH20 + 1 £N2 + |O2
By weight 227 = 132 + 45 +42+8
By volume 2 = 3+ 2^ + ii + £
The weights of the several products of the above re-
actions are calculated by multiplying their specific gravi-
ties by the weight of I litre of hydrogen at o° C. and 760
mm. (0.0896 grm). Thus,
One litre of CO2 — 22 x .0896= 1.9712 grm.
H2O= 9x „ =0.8064 „
,, No =i4x „ =1.2544 „
62 =i6x „ =1.4336 „
The volume of permanent gases at o° and 760 mm. is
PRESSURE GAUGES. 277
constant, and assuming the gramme as the unit of mass,
is found to be 22.32 litres. Thus : —
Volume of 44 of CO., at O° and 760 mm. = j-™^ — 22.32 litres.
28 ,, N2 „ ,, -
32,, 02 „ ,, -¥—=22.32 „
Therefore
132 grms. of CO2 at O° C and 760 mm. —22.32 x 3 =66.96 litres.
45 » H2O » ,» = 22.32x2^ = 55.80 ,,
42 „ N2 „ „ = 22.32x1^ = 33.48 „
8 „ O, „ ,, =22.32 x j = 5.58 „
161.82 ,,
Therefore I gram-molecule or 227 grms. of nitro-glycerine
when exploded, produces 161.82 litres of gas at o° C and
760 mm.
To determine the volume of gas at the temperature of
explosion, we simply apply the law of Charles.* Thus —
in which V represents the original volume.
V ,, new volume.
T ,, original temperature on the absolute scale.
T ,, new temperature of the same scale.
In the present case T' = 6ooi°.
Therefore substituting, we have
,rt 161.82x6001
V'= - 273 =3557 litres.
or at the temperature of explosion I gram-molecule of
nitro-glycerine produces 3,557 litres of permanent gas.
Pressure or Crusher Gauge. — There are many forms
of this instrument. As long ago as 1792 Count Rumford
* According to the law of Charles, the volume of any gas varies
directly as its temperature on the absolute scale, provided the pressure
remains constant. Knowing the temperature on the centigrade scale,
the corresponding temperature on the absolute scale is obtained by
adding 273 to the degrees centigrade.
278
NITRO-EXPLOSIVES.
used a pressure gauge. The so-called crusher gauge was,
however, first used by Captain Sir Andrew Noble in his re-
searches on powder. Other forms are the Rodman * punch
Uchatius Eprouvette, and the crusher gauge of the English
Commission on Explosives. They are all based either
upon the size of an indent made upon a copper disc by a
steel punch fitted to a piston, acted upon by the gases of
FIG. 55. — PRESSURE GAUGE.
the explosive, or upon the crushing or flattening of copper
or lead cylinders.
Berthelot uses a cylinder of copper, as also did the
English Commission, but in the simpler form of apparatus
mostly used by manufacturers lead cylinders are used.
This form of apparatus (Fig. 55) consists of a base of iron
to which four uprights a are fixed, set round the circum-
ference of a 4-inch circle ; the lead plug rests upon the
* Invented by General Rodman, United States Engineers.
PRESSURE GAUGE. 279
steel base let into the solid iron block. A ring c holds the
uprights d together at the top. The piston b, which rests
upon the lead plug, is a cylinder of tempered steel 4 inches
in diameter and 5 inches in length ; it is turned away at
the sides to lighten it as much as possible. It should move
freely between the uprights d. In the top of this cylinder
is a cavity to hold the charge of explosive. The weight of
this piston is \2\ Ibs. The shot e is of tempered steel, and
4 inches in diameter and 10 inches in length, and weighs 34!
Ibs. It is bored through its axis to receive a capped fuse.
The instrument is used in the following manner : — A
plug of lead i inch long and I inch in diameter, and of a
cylindrical form, is placed upon the steel plate between the
uprights a, the piston placed upon it, the carefully weighed
explosive placed in the cavity, and the shot lowered gently
FIG. 56. — b, STEEL PUNCH ; c, LEAD CYLINDER FOR USE WITH
PRESSURE GAUGE.
upon the piston. A piece of fuse, with a detonator fixed at
one end, is then pushed through the hole in the shot until
it reaches the explosive contained in the cavity in the piston.
The fuse is lighted. When the charge is exploded, the shot
is thrown out, and the lead cylinder is more or less com-
pressed. The lead plugs must be of a uniform density and
homogeneous structure, and should be cut from lead rods
that have been drawn, and not cast separately from small
masses of metal.
The strength of the explosive is proportional to the
work performed in reducing the height of the lead (or
copper) plug, and to get an expression for the work done it
is necessary to find the number of foot-pounds (or kilo-
280 NITRO-EXPLOSIVES.
grammetres required to produce the different amounts of
compression. This is done by submitting exactly similar
cylinders of lead to a crushing under weights acting without
initial velocity, and measuring the reduced heights of the
cylinders ; from these results a table is constructed estab-
lishing empirical relations between the reduced heights and
the corresponding weights ; the cylinders are measured
both before and after insertion in the pressure gauge by
means of an instrument known as the micrometer calipers
(Fig. 57).*
The Use of Lead Cylinders. — The method of using
lead cylinders to test the strength of an explosive is a very
simple affair, and is conducted as follows : — A solid cast
lead cylinder, of any convenient size, is bored down the
centre for some inches, generally until the bore-hole reaches
FIG. 57. — MICROMETER CALIPERS FOR MEASURING DIAMETER OF
LEAD CYLINDERS.
to about the centre of the block. The volume of this hole
is then accurately measured by pouring water into it from
* An instrument called a "Foot-pounds Machine" has been in-
vented by Lieut. Quinan, U.S. Army. It consists of three boards,
connected so as to form a slide 16 feet high, in which a weight (the
shot of the pressure gauge) can fall freely. One of the boards is
graduated into feet and half feet. The horizontal board at the bottom,
upon which the others are nailed, rests upon a heavy post set deep in
the ground, upon which is placed the piston of the gauge, which in this
case serves as an anvil on which to place the lead cylinders. The
shot is raised by means of a pulley, fixed at the top of the structure, to
any desired height, and let go by releasing the clutch that holds it.
The difference between the original length and the reduced length
gives the compression caused by the blow of the shot in falling, and
gives the value in foot-pounds required to produce the different amounts
of compression. (Vide Jour. U.S. Naval Inst., 1892.)
LEAD CYLINDERS.
28l
a graduated measure, and its capacity in cubic centimetres
noted. The bore-hole is then emptied and dried, and a
weighed quantity (say 10 grms.) of the explosive pressed
well down to the bottom of the hole. A hole is then made
in the explosive (if dynamite) with a piece of clean and
rounded glass rod, large enough to take the detonator. A
piece of fuse, fitted with a detonator, is then inserted into
the explosive and lighted. After the explosion a large
pear-shaped cavity will be found to have been formed, the
volume of which is then measured in the same way as before.
The results thus obtained are only relative, but are of
considerable value for comparing dynamites among them-
selves (or gun-cottons). Experiments in lead cylinders gave
the relative values for nitro-glycerine 1.4, blasting gelatine
FIG. 58. — LEAD CYLINDERS BEFORE AND AFTER USE.
1.4, and dynamite i.o. (Fig. 58 shows sections of lead
cylinders before and after use.)
Standard regulations for the preparation of lead cylin-
ders may be found in the Chem. Zeit., 1903, 27 [74], 898.
They were drawn up by the Fifth International Congress
of App. Chem., Berlin. The cylinder of lead should be 200
mm. in height and 200 mm. in diameter. In its axis is a
bore-hole, 125 mm. deep and 25 mm. in diameter. The
lead used must be pure and soft, and the cylinder used in
a series of tests must be cast from the same melt. The
temperature of the cylinders should be 15° to 20° through-
out. Ten grms. of explosive should be used and wrapped
in tin-foil. A detonator with a charge of 2 grms., to be
fired electrically, is placed in the midst of the explosive.
The cartridge is placed in the bore-hole, and gently pressed
282
NITRO-EXPLOSIVES.
against the bottom, the firing wires being kept in central
position. The bore-hole is then filled with dry quartz sand,
which must pass through a sieve of 144 meshes to the sq.
cm., the wires being .35 mm. diameter. The sand is filled
in evenly, any excess being levelled off. The charge thus
prepared is then fired electrically. The lead cylinder is
then inverted, and any residues removed with a brush.
The number of c.c. of water required to fill the cavity, in
excess of the original volume of the bore-hole, is a measure
of the strength of the explosive. The results are only
comparable if made with the same class of explosive. A
FIG. 59.— NOBLE'S PRESSURE GAUGE.
I
result is to be the mean of at least three experiments. The
accuracy of the method depends on (a) the uniform tem-
perature of the lead cylinder (15° to 20° C. 7); (fr) on the
uniformity of the quartz sand ; (c) on the uniformity of the
measurements.
Noble's Pressure Gauge. — The original explosive
vessels used by Captain Sir A. Noble in his first experi-
ments were practically exactly similar to those that he
now employs, which consists of a steel barrel A (Fig. 59),
open at both ends, which are closed by carefully fitted
screw plugs, furnished with steel gas checks to prevent any
escape past the screw. The action of the gas checks is
PRESSURE GAUGE. 283
exactly the same as the leathers used in hydraulic presses.
The pressure of the gas acting on both sides of the annular
space presses these sides firmly against the cylinder and
against the plug, and so effectually prevents any escape.
In the firing plug F is a conical hole closed by a cone fitting
with great exactness, which, when the vessel is prepared for
firing, is covered with fine tissue paper to act as an insulator.
The two firing wires G G, one in the insulated cone, the other
in the firing plug, are connected by a very fine platinum
wire passing through a glass tube filled with meal powder.
The wire becomes red-hot when connection is made with a
Leclanche battery, and the charge which has previously
been inserted into the vessel is fired. The crusher plug is
fitted with a crusher gauge H for determining the .pressure
of the gases at the moment of explosion, and in addition
there is frequently a second crusher gauge apparatus
screwed into the cylinder. When it is desired to allow the
gases to escape for examination, the screw J is slightly
withdrawn. The gases then pass into the passage I, and
can be led to suitable apparatus in which their volume can
be measured, or in which they can be sealed for subsequent
chemical analysis.
The greatest care must be exercised in carrying out
experiments with this apparatus ; it is particularly neces-
sary to be sure that all the joints are perfectly tight before
exploding the charge. Should this not be the case, the
gases upon their generation will cut their way out, or com-
pletely blow out the part improperly secured, in either case
destroying the apparatus. The effect produced upon the
apparatus when the gas has escaped by cutting a passage
for itself is very curious. The surface of the metal where
the escape occurred presents the appearance of having been
washed away in a state of fusion by the rush of the highly
heated products.
The Pressure Gauge. — The pressure is found by the
use of a little instrument known as the pressure gauge
284
NITRO-EXPLOSIVES.
which consists of a small chamber formed of steel, inside
of which is a copper cylinder, and the entrance being closed
by a screw gland, in which a piston, having a definite
sectional area, works. There is a gas check E (Fig. 60)
placed in the gland, and over the piston, which prevents
the admission of gas to the chamber. When it is desired
to find the pressure in the chamber of a gun, one or more
of these crushers are made up with or inserted at the
extreme rear end of the cartridge, in order to avoid their
being blown out of the gun when fired. This, however,
often takes place, in which case the gauges are usually
r"
FIG. 60.— CRUSHER GAUGE. £, GAS CHECK.
found a few yards in front of the muzzle. The copper
cylinders which register the pressure are made 0.5 inch
long from specially selected copper, the diameters being
regulated to give a sectional area of either TV or ^V square
inch.
Hollow copper cylinders are manufactured with reduced
sectional areas for measuring very small pressures. It has
been found that these copper cylinders are compressed to
definite lengths for certain pressures with remarkable uni-
formity. Thus a copper cylinder having a sectional area
of TV square inch, and originally J inch long, is crushed to
a length of 0.42 inch by a pressure of 10 tons per square
inch. By subsequently applying a pressure of 12 tons per
square inch the cylinder is reduced to a length of 0.393 inch.
Before using the cylinders, whether for experimenting with
closed vessels or with guns, it is advisable to first crush
them by a pressure a little under that expected in -the
experiment. Captain Sir A. Noble used in his experiments
PRESSURE DEVELOPED BY EXPLOSION. 285
a modification of Rodman's gauge. (Ordnance Dept,
U.S.A., 1861.)
By Calculation. — To calculate the pressure developed
by the explosion of dynamite in a bore-hole 3 centimetres
in diameter, charged with I kilogramme of 75 per cent,
dynamite, Messrs Vieille and Sarrau employ the following
formula : —
V-v.
Where Vo = the volume (reduced to o° and 760 mm.) of
the gases produced by a unit of weight of the explosive ;
Q the number of calories disengaged by a unit of weight
of the explosive ; c equals the specific heat at constant
volume of the gases ; V the volume in cubic centimetres
of a unit of weight of the explosive ; v the volume occupied
by the inert materials of the explosive. The volume of
gas produced by the explosion of I kilogramme of nitro-
glycerine (at o° and 760 mm.) is 467 litres.
Vo will therefore equal 0.75 X 467 = 350.25.
The specific heat c is, according to Sarrau, .220 (c] ; and
according to Bunsen, I kilogramme of dynamite No. I dis-
engages 1,290 (Q) calories. The density of dynamite is
equal to 1.5, therefore
If we take the volume of the kieselguhr as .1, we find from
above formula that
P = 3 qo( i H -- - - ) = 1 3,QOO atmospheres,
•" \ 273X.222/
.600 — . I
which is equal to 14,317 kilogrammes per square centi-
metre. The pressure developed by I kilogramme of pure
286 NITRO-EXPLOSIVES.
nitroglycerine equals 18,533 atmospheres, equals 19,151
kilogrammes. Applying this formula to gun-cotton, and
taking after Berthelot, Q=iO75, and after Vieille and
Sarrau, Vo = 67i litres, and c as .2314, and the density of
the nitro-cellulose as 1.5, we have (V = O)
1075
=671(1
273 x. 2314
= 18,135 atmospheres.
.666
To convert this into pressure of kilogrammes per square
centimetre, it is necessary to multiply it by the weight of a
column of mercury 0.760 m. high, and I square centimetre
in section, which is equal to increasing it by TJV It thus
becomes
p* =(i+3v).
P*= 18,135 X 1.033 = 18,733 kilogrammes.
The following tables, taken from Messrs William
Macnab's and E. Ristori's paper (Proc. Roy. Soc., 56,
8-19), " Researches on Modern Explosives," are very in-
teresting. They record the results of a large number of
experiments made to determine the amount of heat evolved,
and the quantity and composition of the gases produced
when certain explosives and various smokeless powders
were fired in a closed vessel from which the air had been
previously exhausted. The explosions were carried out in
a " calorimetric bomb " of Berthelot's pattern.*
* For description of " bomb," see " Explosives and their Power,"
Berthelot, trans, by Hake and Macnab, p. 150. (Murray.)
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288
NITRO-EXPLOSIVES.
TABLE SHOWING THE HEAT DEVELOPED BY EXPLOSIVES CON-
TAINING NITRO- GLYCERINE AND NITRO- CELLULOSE IN
DIFFERENT PROPORTIONS.
Composition of Explosives.
Calories per cent.
Nitro-cellulose (N — 13.3 per cent.).
Nitro-glycerine.
ioo per cent, dry pulp
0
1061
100 „ gelatinised -
0
922
90
10 per cent.
1044
80 „ - - - '- -
20
1159
70
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1267
60 „ - - - -
40
1347
50
5o
1410
40
60
1467
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1652
Nitro-cellulose (N = 12.24 Per cent.).
Nitro-glyceiine.
80 per cent. -
20 per cent.
IO62
60 „
40 „
1288
50 „ . . . .
50
1349
40 »
60
1405
Nitro-cellulose (N = 13.3 per cent.).
Nitro-glycerine.
Vaseline.
55 per cent. . . .
40 per cent.
5 per cent. 1134
35 ...
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290
NITROEXPLOSIVES.
Composition of some of the Explosives in
Common Use.
Ordinary Dynamite.
Nitro-Glycerine - 75 per cent.
Kieselguhr - - 25 „
Amvis.
Nitrate of Ammonia 90 per cent.
Chloro - di - nitro
Benzene 5 ,,
Wood Pulp 5 „
Ammonia Nitrate Powder.
Nitrate of Ammonia 80 per cent.
Chlorate of Potash 5 „
Nitro-Glucose - 10 „
Coal Tar
Celtite.
Nitro-Glycerine
Nitro-Cotton
KN03
Wood Meal -
5
56-59 parts.
2-3-5
17-21
89
Ammonium Oxalate 11-13
Moisture - - 0.5-1.5
Atlas Powders.
Sodium Nitrate - 2.0 p. ct.
Nitro-Glycerine - 75.0 „
Wood Pulp - - 21.0 „
Magnesium Carbonate 2.0 „
Dualine.
Nitro-Glycerine - 50 per cent.
Sawdust - - 30 „
Nitrate of Potash 20 „
Vulcan Powder.
Nitro-Glycerine
Nitrate of Soda
Sulphur
Charcoal
30 per cent.
52.5 „
7-0 „
Vigorite.
Nitro-Glycerine - 30 per cent.
Nitrate of Soda - 60 „
Charcoal 5 „
Sawdust 5 „
Rendrock.
Nitrate of Potash 40 per cent.
Nitro-Glycerine - 40 „
Wood Pulp - - 13 „
Paraffin or Pitch - 7 „
Ammonia Nitrate Powder.
Ammonia Nitrate 80 per cent.
Potassium Chlorate 5 „
Nitro-Glucose
Coal Tar
10
5
Hercules Powders.
Nitro-Glycerine
75 to 40 p. ct.
Sugar - - i „ 15.66 „
Chlorate of
Potash . 1.05 „ 3.34 „
Nitrate of
Potash 2.10 ,, 31.00 „
Carbonate of
Magnesia 20.85 »> 10.00 „
Carbo- Dynamite.
Nitro-Glycerine - 90 per cent.
Charcoal - - 10 „
Geloxite (Permitted List).
Nitro-Glycerine - 64-54 parts.
Nitro-Cotton - 5- 4
Nitrate of Potash 22-13
Ammonium Oxalate 15-12
Red Ochre - - i- o
WTood Meal - -7-4
The Wood Meal to - contain
not more than 15 % and not less
than 5 °/0 moisture.
COMPOSITION OF EXPLOSIVES.
291
Giant Powder.
Nitro-Glycerine - 40 per cent.
Sodium Nitrate - 40 „
Rosin - - - 6 „
Sulphur 6 „
Guhr - - - 8 „
Dynamite de Trauzel.
Nitro-Glycerine - 75 parts.
Gun-Cotton 25 ,.
Charcoal - - 2 „
Rhenish Dynamite.
Solution of N.G. in
Naphthalene - 75 per cent.
Chalk, or Barium
Sulphate - - 2 „
Kieselguhr - - 23 „
Ammonia Dynamite.
Ammonia Nitrate 75 parts.
Paraffin - 4 »
Charcoal - 3 „
Nitro-Glycerine - 18 „
Blasting Gelatine.
Nitro-Glycerine - 93 per cent
Nitro-Cotton 3 to 7 „
Gelatine Dynamite.
Nitro-Glycerine - 71 per cent.
Nitro-Cotton - 6 „
Wood Pulp 5 „
Potassium Nitrate 18 „
Gelignite.
Nitro-Glycerine 60 to 6 1 p. ct.
Nitro-Cotton - 4 „ 5 „
Wood Pulp - - 9 „ 7 „
Potassium Nitrate 27 „
Forcite.
Nitro-Glycerine - 49 per cent.
Nitro-Cotton - i.o „
Sulphur - -i-5 »
Tar - - - 10.0 „
Sodium Nitrate - 38.0 „
Wood Pulp 5 »
(The N.-G., &c, varies.)
Tonite No. i.
Gun-Cotton 52-50 per cent.
Barium Nitrate 47-40 „
Tonite No. 2.
Contains Charcoal also.
Tonite No. 3.
Gun-Cotton 1 8 to 20 p. ct.
Ba(NO3)2 - 70 „ 67 „
Di-nitro-Benzol n „ 13 „
Moisture
0.5
Carbonite.
1 7.76 p. ct.
1.70 „
0.42 „
34.22 „
9-7i „
i-55 »
34-27 „
0.36 „
Nitro-Glycerine -
Nitro-Benzene
Soda -
KN03 -
Ba(NO3)2 -
Cellulose
Cane Sugar -
Moisture
Roburite.
Ammonium Nitrate 86 p. ct.
Chloro-di-nitro-Benzol 14 „
Faversham Powder.
Ammonium Nitrate 85 p. ct.
Di-nitro-Benzol - 10 „
Trench's Flame-ex-
tinguishing Com-
pound - - 5 »
Favierite No. i.
Ammonium Nitrate 88 p. ct.
Di-nitro-Naphthalene 12 „
Favierite No. 2.
No. i Powder - - 90 p. ct.
Ammon. Chloride - 10 „
Bellite.
Ammonium Nitrate 5 parts.
Meta-di-nitro-Benzol i „
292
NITRO-EXPLOSIVES.
Petrofacteur.
Nitro-Benzene - - 10 p. ct.
Chlorate of Potash - 67 „
Nitrate of Potash - 20 „
Sulphide of Antimony 3 „
Securite.
Mixtures of
Meta-di-nitro-Benzol 26 p. ct. j
and
Nitrate of Ammonia 74 „ >
Rack-a-Rock.
Potassium Chlorate 79 parts.
Mono-nitro-Benzene 21 „
Oxonite.
Nitric Acid (sp.gr. 1.5) 54 parts.
Picric Acid - - 46 „
Emmensite.
Emmens Acid - 5 parts.
Ammonium Nitrate 5 „
Picric Acid 6 „
Brugere Powder.
Ammonium Picrate 54 p. ct.
Nitrate of Potash - 46 „
Designolle's Torpedo Powders.
Potassium Picrate 55 to 50 p. ct.
Nitrate of Potash 45 „ 50 „
Stowite.
Nitro-Glycerine 58 to 61 parts.
Nitro-Cotton 4.5 „ 5 „
Potassium
Nitrate - 18 „ 20 „
Wood Meal - 6 „ 7 „
Oxalate of
Ammonia- n „ 15 „
The Wood Meal shall con-
tain not more than 15 % and
not less than 5 % by weight of
moisture. The explosive shall
be used only when contained in
a non-water-proofed wrapper of
parchment — No. 6 detonator.
Faversham Powder.
Nitrate of Ammonium 93 to 87
Tri-nitro-Toluol - 1 1 „ 9
Moisture - - i „ —
Kynite.
Nitro-Glycerine 24-26 parts.
Wood-Pulp - 2.5- 3.5 „
Starch- - 32.5- 3.5 „
Barium Nitrate 31-5-34-5 »
CaCO3 - - o - 0.5 „
Moisture - - 3.0- 6.0 „
Must be put up only in water-
proof parchment paper, and
No. 6 electric detonator used.
Rexite.
Nitro-Glycerine 6.5-8.5 parts.
Ammonium
Nitrate - - 64-68 „
Sodium Nitrate - 13-16 „
Tri-nitro-Toluene 6.5-8.5 „
Wood Meal - - 3- 5 „
Moisture - - .5-1.4 „
Must be contained in water-
proof case (stout paper), water-
proofed with Resin and Cerasin
— No. 6 detonator.
Withnell Powder.
Ammonium Nitrate 88-92 parts.
Tri-nitro-Toluene 4-6 „
Flour (dried at 100° C. 4- 6 „
Moisture - - 0-15 „
Only to be used when con-
tained in a linen paper cartridge,
water - proofed with Carnuba
Wax, Paraffin — No. 7 detonator
used.
Phenix Powder.
Nitro-Glycerine 28-31 parts.
Nitro-Cotton - o- i „
Potassium Nitrate 30-34 „
Wood Meal - 33-37* „
Moisture - - 2- 6 „
COMPOSITION OF EXPLOSIVES.
293
SMOKELESS POWDERS.
Cordite.
Nitro-Glycerine
58 p. ct. + or-.75
Nitro-Cotton 37 „ +or-.65
Vaseline - 5 „ +or-.25
Cordite, M.D.
Nitro-Glycerine
30 p. ct. + or- i
Nitro-Cotton 65 „ -for- i
Vaseline - 5 „ +or-.25
Analysis of —
By W. Macnab and A. E.
Leighton.
E.G. Powder.
Nitro-Cotton - 79.0 p. ct.
Potassium Nitrate 4.5 „
Barium Nitrate - 7.5 „
Camphor - - 4.1 „
Wood Meal 3.8 „
Volatile Matter - i.i „
Walsrode Powder.
Nitro-Cotton 98.6 p. ct.
Volatile Matter - 1.4 „
Kynoch's Smokeless.
Nitro-Cotton - 52.1 p. ct.
Di-nitro-Toluene 19.5 „
Potassium Nitrate 1.4 ,,
Barium Nitrate - 22.2 „
Wood Meal 2.7 „
Ash - 0.9 „
Volatile Matter - 1.2
Schultze.
Nitro-Lignin - =62.1 p. ct.
Potassium Nitrate = 1.8 „
Barium Nitrate - =26.1 „
Vaseline - - 4.9 „
Starch 3.5 „
Volatile Matter - i.o
Imperial Schultze.
80. i p. ct.
Nitro-Lignin
Barium Nitrate - 10.2
Vaseline - - 7.9
Volatile Matter - 1.8
Cannonite.
Nitro-Cotton 86.4 p. ct.
Barium Nitrate - 5.7 „
Vaseline - - 2.9 ,,
Lamp Black 1.3 „
Potassium Ferro-
cyanide - 2.4 „
Volatile Matter - 1.3 „
Amberite.
Nitro-Cotton - 71.0 p. ct.
Potassium Nitrate 1.3 „
Barium Nitrate - 18.6 „
Wood Meal 1.4 „
Vaseline - - 5.8 „
Sporting- Ballistite.
Nitro-Glycerine - 37.6 p. ct.
Nitro-Cotton - 62.3 „
Volatile Matter - o.i „
294
NITRO-EXPLOSIVES.
The following is a complete List of the Permitted Explosives as
Defined in the Schedules to the Explosives in Coal Mines Orders
of the 2oth December 1902, of the 24th December 1903, of the 5th
September 1903, and loth December 1903 : —
Albionite.
Ammonal.
Ammonite.
Amvis.
Aphosite.
Arkite.
Bellite No. i.
Bellite No. 2.
Bobbinite.
Britonite.
Cambrite.
Carbonite.
Clydite.
Coronite.
Dahmenite A.
Dragonite.
Electronite.
Faversham Powder.
Fracturite.
Geloxite.
Haylite No. i.
Kynite.
Negro Powder.
Nobel's Ardeer
Powder.
Nobel Carbonite.
Normanite.
Pit-ite.
Roburite No. 3.
Saxonite.
Stow-ite.
Thunderite.
Victorite.
Virite.
West Falite No. i.
West Falite No. 2.
INDEX.
ABEL'S, Sir Frederick, method of
manufacturing gun-cotton, 57.
Abel's heat test, 249.
Acid mixture for nitrating nitro-
glycerine, 23.
Air pressure in nitrator, 28.
Alkalinity in nitro-cellulose, 217.
Amberite, 189.
Ammonite, 149.
Analyses of collodion-cotton, 81.
gelatine dynamites, 123.
Analysis of explosives, 197.
acetone, 209.
blasting gelatine, 199.
cap composition, 241.
cordite, 206.
celluloid, 230.
dynamite, 197*
forcite, 202.
fulminate, 240.
glycerine, 233.
gun-cotton, 212.
nitric acid, 24.
picric acid, 230.
tonite, 205.
waste acids, 239.
Armstrong on the constitution of the
fulminates, 159.
Atlas powder, 119.
Auld on acetone, 211.
Axite, 176.
BALLISTITE, 179.
Beater or Hollander for pulping
gun-cotton, 64.
Bedson, Prof., on roburite explosion
gases, 140.
Bellite, 142.
Benzene, explosives derived from, 132.
Benzene, mono-nitro- and di-nitro-
benzene, 134.
Bergmann and Junk on nitro-cellulose
tests, 268.
Bernthsen summary of nitro-benzenes,
133-
Blasting gelatine, 119.
Blasting charge, preparation of, 166.
B.N. powder, 190.
Boiling-point of N.G., 19.
Boutnny's nitro-glycerine process, 15.
296
INDEX.
Brown on wet gun-cotton, 56.
Brugere's powder, 195.
Bucknill's resistance coil, 13.
CALCULATION of volume of gas
\^^ evolved in an explosive reaction,
276.
Cannonite, 189.
Cellulose, 2, 47.
Celluloid manufacture, 91.
analysis, 230.
cartridges, 91.
uses of, 90.
Field's papers on, 93.
fibre for, 94.
nitration of fibre, &c., 95.
formula of, 57.
Champion and Pellet's method of de-
termining nitrogen, 223.
Chenel's modification of Kjeldahl's
method, 227.
Collodion-cotton, 79.
Comparative tests of black and nitro-
powders, 193.
Compressing gun-cotton, 77-
Composition of waste acids from nitro-
glycerine, 43.
Composition of some common ex-
plosives, 290.
Conduits for nitro-glycerine, 7.
Cooppal powder, 5, 189.
Cordite manufacture, 169.
analysis, 206.
Cresilite, 158.
Cross and Bevan on nitro-jute, 107.
Crusher gauge, 284.
Cundill, Colonel, classification of
dynamites, 112.
DANGER area, 5.
Dangers in the manufacture of
gun-cotton, 85.
Decomposition of cellulose, 54.
Definition of explosives in Order of
Council (Explosives Act), i.
Determination of N2O4 in nitric acid, 24.
Determination of strength of H2SO4, 25.
Determination of relative strength of
explosives, 272.
Detonators, 163.
Di-nitro-toluene, 138.
Dipping cotton in manufacture of gun-
cotton, 60.
Divers and Kawakita on the fulminates,
159-
Dixon, Prof. H. B., on roburite ex-
plosions, 139.
Drying house for gun-cotton, 122.
Dynamite, efficiency of, 118.
frozen dynamite, 116.
gelatine dynamite, 119.
properties of kieselguhr dynamite,
116.
Reid & Borland's carbo-dynamite,
119.
Rhenish dynamite, 119.
various kinds of, 119.
EC. powder, 186.
• Electronite, 151.
Emmensite, 195.
Equation of formation of nitro-glycerine,
16.
Equation of formation of nitro-cellulose,
50-
Exploders, electric, 167.
Explosion gases of dynamite, 19.
nitro-glycerine, 18.
gun-cotton, 55.
roburite, 139.
Exudation test gelatines, 257.
CAVERSHAM powder, 147.
-I Favier's explosive, 149.
Field on celluloid, 93, 99.
INDEX.
297
Firing-point of explosives, 247.
Filite, 1 80.
Filtering nitro-glycerine, 37.
Flameless explosives, 89, 138, 144.
Formation of white matter in the nitra-
tion of N.G., 39.
Forcite, 119.
France, 82.
Free fatty acid in glycerine, 39, 235.
Freeing nitric acid from N9O4, 25.
Freezing-point of N.G., 21.
French Commission on Ammonium
Nitrate, 142.
Fulminates constitution, 159.
Fulminate of mercury, I59» 240.
Fulminate of silver, 161.
Fuses, various kinds of, 166.
GASES formed by the decomposi-
tion of nitro-glycerine, 1 8.
Gelatine explosives, analysis of, 199.
Glycerine, analysis of, 233.
formula of, 16.
nitration of, 23.
Greiner's powder, 190.
Gun-cotton, analysis of, 212.
boiling, 64.
complete series of, 52, 54.
compressing, moulding, and pack-
ing, 67, 77, 78.
dipping and steeping the cotton, 60.
drying the cotton, 58.
granulation of, 79.
manufacture of, 57.
Abel's method, 57.
Stowmarket, 57.
Waltham Abbey, 71.
products of decomposition of, 55.
properties of, 54.
pulping, 65.
washing, 63.
as a mining explosive, 56.
Guttmann's nitric acid plant, 45.
Guttmann's heat test, 256.
H ANDY'S method for determining
moisture in dynamite, 197.
Hannah, Dr N., on roburite explosion
gases, 139.
Heat developed by explosives contain-
ing nitro-glycerine, &c., 288.
Heat test, Abel, 249.
Hellhoffite, 152.
Henrite powder, 191.
Hollander, 65.
Horsley's apparatus, 248.
Hydro-extractors for wringing out gun-
cotton, 62.
IMPURITIES in commercial glyce-
1 rine, 39, 233.
Impurities in fulminate, 240.
nitro-glycerine, 38.
picric acid, 231.
KETONES as solvents for pyroxy-
line, 101.
Kieselguhr dynamite, 112.
Kinetite, 145.
Kjeldahl method of determining nitro-
gen, 227.
LE BOUCHET, manufacture of gun-
cotton at, 78.
Lead cylinders for testing strength of
explosives, 281.
Lenk's improvements in gun-cotton
manufacture, 49.
Lewes on the pressure of cordite, 175.
Leibert's treatment of nitro-glycerine,
30.
Lightning conductors for danger build-
ings, 10.
Liquefaction test for gelatine, 257.
Lodge on lightning conductors, 8.
298
INDEX.
Lowering of freezing-point of N.G., 21.
Lunge's nitrometer, 219.
Lydite, 156.
IVyTANUFACTURE of gun-cotton,
Manufacture of nitro-glycerine, 17.
cordite, 169.
roburite, 140.
fulminates, 162.
tonite, 84.
di-nitro-benzene, 138.
nitro-starch, 103.
celluloid, 91.
Majendie (Col. Sir V. D. ), report on a
picric acid explosion, 155.
Maximite, 191.
Maxim's detonator mixture, 165.
M' Robert's mixing machine, 126.
Mechanical equivalent of explosives,
273.
Melinite, 156.
Mono - nitro - glycerine, di-nitro-nitro-
glycerine, 41.
Moulding gun-cotton, 77.
Mounds for protection of danger build-
ings, 6.
Mortar for ballistic tests, 275.
Mowbray on use of compressed air, 15.
Miihlhausen on nitro-starch, 4, 5, 103.
NATHAN'S nitrator, 32.
Nitric peroxide in N.G., 24.
Nitration products of cellulose, 52, 54.
Nitro-glycerine, analysis of, 198.
properties, 17.
nitration, 23.
separation, 35.
washing, 37.
uses of, 41.
manufacture of, 17.
Nitro-benzene, properties and manu-
facture of, 132, 137.
Nitro-cellulose, 2, 47, 60, 212.
Nitro-jute, 5, 107.
Nitro-mannite, 4, 109.
Nitro-naphthalene, 148.
Nitro-starch, 4, 103.
Nitro-toluene, 132.
Nitrated gun-cotton, 83.
Nitrogen, determination of, Lunge
method, 219.
Champion and Pellet's, 223.
Schultze-Tieman, 224.
Kjeldahl-Chenel's, 227.
percentages of in various explosives,
228.
Nitrometers, Lunge, Horn's, &c., 220,
222.
Nobel's ballistic test, 274.
Noble's pressure gauge, 282.
experiments on cordite, 172.
Normal powder, 191.
OLE 1C acid in glycerine, 236.
Orsman on roburite, 142.
Oxonite, 152.
Oxy-cellulose, 102.
PACKING gun-cotton, 78.
dynamite, 116.
Page's regulator, 260.
Panclastite, 152.
Percentage composition of nitro-glyce-
rine, 1 8.
Perkin on magnetic rotation of nitro-
glycerine, 19.
Phenol, tri-nitro-phenol, 152.
Picric acid, 152, 231.
powders, 157, 189.
Picrates, 154, 231.
Polarised light and nitro-cellulose, 2 1 8.
Position of the N(X group in nitro-
explosives, 2, 3, 16.
Prentice's nitric acid plant, 43.
Pressure gauge, 282.
INDEX.
299
Primers of gun-cotton, 166.
Properties of dynamite, 116.
gelatine compounds, 130.
Pulping gun-cotton, 65.
Pyroxyline for celluloid, 96.
solvents for, 101.
Q
UINAN'S foot-pound machine,
280.
RAOULT'S law and N.G., 21.
Reworked gun-cotton, 78.
Rhenish dynamite, 119.
P.oburite, properties and manufacture
of, 138.
Bedson's report on, 140.
Orsman on gases produced by
explosion of, 142.
Romit, 148.
SARRAU and Vieille, gases obtained
from ignition of dynamite, 19.
Sayers, 50.
Scheme for analysis of explosives, 213.
Schultze's powder, 183.
Schultze-Tieman method of determining
nitrogen, 224.
Securite, 144.
Separation of nitro-glycerine from mixed
acids, 35.
Shimose, 156.
Silver test for glycerine, 233.
Smokeless powders, 1 68.
Smokeless diamond, 190.
Snyder's powder, 193.
Sobrero discovered nitro-glycerine, 14.
Sodium nitrate, analysis of, 239.
Soluble and insoluble nitro-cellulose, 51.
Solubility of nitro-glycerine, 20.
Solvents for soluble gun-cotton, 52, 101.
Solubility test for gun-cotton, 214.
Specific gravity of explosives, 270.
Sprengel's explosives, 151.
Stowmarket, manufacture of gun-cotton
at, 57-
Sulphuric acid, determination of strength
of, 24.
Sy on test for nitro-cellulose, 269.
TEMPERATURE of nitration of
nitro-glycerine, 29.
Thomson's patents, 73-
Toluene, 146.
Tonite, 84, 146.
analysis of, 205.
fumes from, 85.
Treatment of waste acids, 43.
Trench's fire-extinguishing compound,
88.
Trebouillet and De Besancele on cellu-
loid manufacture, 92.
Tri-nitro-cresol, 158.
Tri-nitro-toluene, 146.
Tri-nitro-phenol, 152.
Tri-nitro-glycerine, 2, 14.
Troisdorf powder, 191, 192.
Turpin's melinite, 156.
US. naval powder, 180.
• Uses of celluloid, 91, 93, 102.
Uses of collodion-cotton, 90.
VASELINE, 208.
Vielle poudre, 190.
Volney's powder, 148.
Von Foster's powder, 191.
WALSRODE powder, 188.
W.A. powder, 182.
Waltham Abbey, manufacture of gun-
cotton at, 71.
manufacture of cordite at, 169.
Walke's pressure gauge results, 289.
300
INDEX.
War Office experiments with cordite,
173-
Washing gun-cotton, 63.
nitro-glycerine, 37.
Waste acids from nitro-glycerine, 41,
226.
Weltern powder, 191.
Werner & Pfleiderer's mixing machine,
124.
Whirling out the acids from gun-cotton,
62.
Will's test for nitro-cellulose, 261.
Wood pulp, 126.
'V'YLONITE Company's process,
TV 96.
ZENGER'S lightning conductors,
II.
Printed at THE DARIEN PRESS, Edinburgh.
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HOLDERS—WORKSHOP NOTES— MANUFACTURING — STORING MATERIALS— RETORT HOUSE
(WORKING) — CONDENSING GAS — EXHAUSTEES, ETC. — WASHING AND SCRUBBING — PURIKICATION
—GASHOLDERS (CARE OF)— DISTRIBUTING GAS— TESTING— ENRICHING PROCESSES— PRODUCT
WORKS— SUPPLEMENTARY.
"The book contains a vast amount of in ormation." — Gas World.
8 CROSBY LOCK WOOD & SON'S CATALOGUE.
GAS FITTING. A Practical Handbook. By JOHN BLACK.
Revised Edition. With 130 Illustrations. Crown Svo, cloth 2s. 6d.
GAS WORKS, their Construction and Arrangement, and the
Manufacture and Distribution of Coal Gas. By S. HUGHES, C.E.
Ninth Edition. Revised by H. O'CONNOR, A.M.Inst C.E. Crown Svo
6s.
GAS MANUFACTURE, CHEMISTRY OF. A Practical
Manual for the use of Gas Engineers, Gas Managers, and Students.
By HAROLD M. ROYLE, Chief Chemical Assistant at the Beckton Gas
Works [Nearly Ready. Price about \ 23. 6d. Net.
PREPARATION OF STANDARD SOLUTIONS — ANALYSIS OF COALS — DESCRIPTION OF VARIOUS
TYPES OF FURNACES — PRODUCTS OF CARBONISATION AT VARIOUS TEMPERATURES — ANALYSIS OF
CRUDE GAS— ANALYSIS OF LIME— ANALYSIS OF AMMONIACAL LIQUOR— ANALYTICAL VALUATION
OF OXIDE OF IRON — ESTIMATION OF NAPHTHALIN — ANALYSIS OF FIRE-BRICKS AND FIRE-CLAY
—ART OF PHOTOMETRY— CARBURETTED WATER GAS— APPENDIX CONTAINING STATUTORY AND
OFFICIAL REGULATIONS FOR TESTING GAS, VALUABLE EXCERPTS FROM VARIOUS IMPORTANT
PAPERS ON GAS CHEMISTRY, USEFUL TABLES, MEMORANDA, ETC.
GOLD WORKING* JEWELLER'S ASSISTANT for Masters
and Workmen, compiled from the Experience of Thirty Years' Work-
shop Practice. By G. E. GEE. Crown Svo 75. 6d.
GOLDSMITH'S HANDBOOK* Alloying, Melting, Reducing,
Colouring, Collecting, and Refining. Manipulation, Recovery of Waste,
Chemical and Physical Properties ; Solders, Enamels, and other useful
Rules and Recipes, etc. By G. E. GEE. Sixth Edition. Crown Svo, cloth
3S.
GOLDSMITH'S AND SILVERSMITH'S COMPLETE
HANDBOOK* By G. E. GEE. Crown Svo, half-bound ... 75.
HALL-MARKING OF JEWELLERY* Comprising an Account
of all the different Assay Towns of the United Kingdom, with the Stamps
at present employed ; also the Laws relating to the Standards and Hall-
marks at the various Assay Offices. By G. E. GEE. Crown Svo 35.
HOROLOGY* MODERN, IN THEORY AND PRACTICE.
Translated from the French of CLAUDIUS SAUNIER, ex-Director of
the School of Horology at Macon, by JULIEN TRIPPLIN, F.R.A.S.,
Besangon Watch Manufacturer, and EDWARD RIGG, M.A., Assayer
in the Royal Mint. With 78 Woodcuts and 22 Coloured Copper Plates.
Second Edition. Super Royal Svo, £2 2s. cloth ; half-calf £2 i os.
"There is no horological work in the English language at all to be compared to this production
of M. Saunier's for clearness and completeness. It is alike good as a guide for the student and as a
reference for the experienced horologist and skilled workman." — Horological Journal.
TRADES & MANUFACTURES, THE INDUSTRIAL ARTS, ETC. 9
INTEREST CALCULATOR* Containing Tables at i, i J, 2, 2 J,
3» 3l> 3l) 4>.4j> 4l) and 5 Per cent. By A. M. CAMPBELL, Author of
" The Concise Calendar." Crown 8vo, cloth.
[Just published. Net 2s. 6d.
.IRON AND METAL TRADES' COMPANION* For
Expeditiously ascertaining the Value of any Goods bought or sold by
Weight, from is. per cwt. to \i2s. per cwt., and from one farthing per
pound to one shilling per pound. By THOMAS DOWNIE. Strongly
bound in leather, 396 pp 95.
" A most useful set of tables. Nothing like them before existed." — Building' News.
"Although specially adapted to the iron and metal trades, the tables will be found useful in every
• other business in which merchandise is bought and sold by weight." — Rail-way News.
IRON-PLATE WEIGHT TABLES* For Iron Shipbuilders,
Engineers, and Iron Merchants. Containing the Calculated Weights of
upwards of 150,000 different sizes of Iron Plates, from i ft. by 6 ins. by
J in. to 10 ft. by 5 ft. by i in. Worked out on the basis of 40 Ibs. to the
square foot of iron of i in. in thickness. By H. BURLINSON and
W. H. SIMPSON. 4to, half-bound £i 55.
XABOUR CONTRACTS* A Popular Handbook on the Law of
Contracts or Works and Services. By DAVID GIBBONS. Fourth Edition
with Appendix of Statutes by T. F. UTTLEY, Solicitor. F'cap. 8vo, cloth
35. 6d.
XAUNDRY MANAGEMENT. A Handbook for Use in Private
and Public Laundries. Crown 8vo, cloth. ... 2s.
1AW FOR MANUFACTURERS, EMPLOYERS AND
OTHERS, ETC See "EVERY MAN'S OWN LAWYER." A Handy-
book of the Principles of Law and Equity. By a BARRISTER. Forty-
fourth (1907) Edition, including the Legislation of 1906. 830 pp. Large
Crown 8vo, cloth Just published. Net 6s. 8d.
SUMMARY OF CONTENTS :— LANDLORD AND TENANT— VENDORS AND PURCHASERS—
(CONTRACTS AND AGREEMENTS — CONVEYANCES AND MORTGAGES — JOINT-STOCK COMPANIES —
^PARTNERSHIP— SHIPPING LAW— DEALINGS WITH MONEY— SURKTISHIP— CHEQUES, BILLS AND
NOTES — BILLS OF SALE — BANKRUPTCY — MASTERS, SERVANTS AND WORKMEN — INSURANCE: LIFE,
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UNFANCY, CUSTODY OF CHILDREN — TRUSTEES AND EXECUTORS — TAXES AND DEATH DUTIES —
CLERGYMEN, DOCTORS, AND LAWYERS — PARLIAMENTARY ELECTIONS — LOCAL GOVERNMENT —
LIBEL AND SLANDER— NUISANCES— CRIMINAL LAW— GAME LAWS, GAMING, INNKEEPERS— FORMS
• OF WILLS, AGREEMENTS, NOTICES, ETC.
" A useful and concise epitome of the law." — Law Magazine.
" A complete digest of the most useful facts which constitute English law."— Globe.
"Admirably done, admirably arranged, and admirably cheap." — Leeds Mercury.
•" A dictionary of legal facts well put together. The book is a very useful one."— Spectator.
io CROSBY LOCKWOOD & SON'S CATALOGUE.
LEATHER MANUFACTURE. A Practical Handbook of Tan-
ning, Currying, and Chrome Leather Dressing. By A. WATT. Fifth
Edition, Revised and Enlarged. 8vo, cloth.
{Just published. Net 125. 6d.
CHEMICAL THEORY OF THE TANNING PROCESS — THE SKIN — HIDES AND SKINS — TANNIN OR
TANNIC ACID — GALLIC ACID — GALLIC FERMENTATION — TANNING MATERIALS — ESTIMATION OF
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OR BATING — TANNING BUTTS FOR SOLE LEATHER — TANNING PROCESSES — TANNING BY PRESSURE
—QUICK TANNING— HARNESS LEATHER TANNING— AMERICAN TANNING— HEMLOCK TANNING-
TANNING BY ELECTRICITY — CHEMICAL TANNING — MISCELLANEOUS PROCESSES — COST OF
AMERICAN TANNING — MANUFACTURE OF LIGHT LEATHERS — DYEING LEATHER — MANUFACTURE
OF WHITE LEATHER— CHROME LEATHER MANUFACTURE — Box CALF MANUFACTURE — CHAMOIS
OR OIL LEATHER MANUFACTURE — CURRYING- MACHINERY EMPLOYED IN LEATHER MANUFAC-
TURE—EMBOSSING LEATHER— FELLMONGERING— PARCHMENT, VELLUM, AND SHAGREEN— GUT
DRESSING— GLUE BOILING — UTILISATION OF TANNER'S WASTE.
" A sound, comprehensive treatise on tanning and its accessories." — Chemical Review.
LEATHER MANUFACTURE. PRACTICAL TAN-
NING: A Handbook of Modern Processes, Receipts, and Suggestions
for the Treatment of Hides, Skins, and Pelts of every description. By
L. A. FLEMMING, American Tanner. 472 pp. Cloth, 8vo... Net 255.
MENSURATION AND GAUGING* A FOCKET.BOOK
containing Tables, Rules, and Memoranda for Revenue Officers, Brewers,
Spirit Merchants, etc. By J. B. MANT. Second Edition. i8mo 45.
" Should be in the hands of every practical brewer." — Brewers' Journal.
METRIC TABLES, A SERIES OF. In which the British Standard
Measures and Weights are compared with those of the Metric System at
present in Use on the Continent. By C. H. BOWLING, C.E. 8vo, cloth
i os. 6d.
" Mr. Dowling's tables are well put together as a ready-reckoner for the conversion of one system
nto the other." — Atheneeum.
METROLOGY, MODERN. A Manual of the Metrical Units and
Systems of the present Century, with an Appendix containing a proposed
English System. By Lowis D'A. JACKSON, A.M.Inst.C.E., Author of
"Aid to Survey Practice," etc. Large crown 8vo, cloth ... I2S. 6d.
"We recommend the work to all interested in the practical reform of our weights and measures. )r
— Nature.
MOTOR CARS FOR COMMON ROADS. By A. J. WALLIS-
TAYLER. 212 pp., with 76 Illustrations. Crown 8vo ... 45. 6d.
MOTOR VEHICLES FOR BUSINESS PURPOSES* A
Practical Handbook for those interested in the Transport of Passengers
and Goods. By A. J. WALLIS-TAYLER, A.M.Inst.C.E. With 134 Illus-
trations. Demy 8vo, cloth. {Just Published. Net 95.
RESISTANCE TO TRACTION ON COMMON ROADS— POWER REQUIRED FOR MOTOR VEHICLES-
LIGHT PASSENGER VEHICLES — HEAVY PASSENGER VEHICLES — LIGHT GOODS VANS — HEAVY
FREIGHT VEHICLES— SELF-PROPELLED VEHICLES FOR MUNICIPAL PURPOSES— MISCELLANEOUS
TYPES OK MOTOR VEHICLES— COST OF RUNNING AND MAINTENANCE.
TRADES & MANUFACTURES, THE INDUSTRIAL ARTS, ETC. II
OILS AND ALLIED SUBSTANCES* AN ANALYSIS.
By A. C. WRIGHT, M.A.Oxon., B.Sc.Lond., formerly Assistant Lecturer
in Chemistry at the Yorkshire College, Leeds, and Lecturer in Chemistry
at the Hull Technical School. Demy 8vo, cloth Net ps.
THE OCCURRENCE AND COMPOSITION OF OILS, FATS, AND WAXES— THE PHYSICAL PRO-
PERTIES OF OILS, FATS, AND WAXES, AND THEIR DETERMINATION — THE CHEMICAL PROPERTIES
OF OILS, FATS, AND WAXES FROM THE ANALYTICAL STANDPOINT— DETECTION AND DETERMI-
NATION OF NON-FATTY CONSTITUENTS — METHODS FOR ESTIMATING THE CONSTITUENTS OF
OILS AND FATS— DESCRIPTION AND PROPERTIES OF THE MORE IMPORTANT OILS, FATS, AND
WAXES, WITH THE METHODS FOR THEIR INVESTIGATION — EXAMINATION OF CERTAIN
COMMERCIAL PRODUCTS.
ORGAN BUILDING (PRACTICAL). By W. E. DICKSON, M.A.,
Precentor of Ely Cathedral. Second Edition. Crown 8vo 2s. 6d.
PAINTS, MIXED. THEIR CHEMISTRY AND TECH-
NOLOGY. By MAXIMILIAN TOCH. With 60 Photomicrographic
Plates and other Illustrations [Just Published. Net i2s.
THE PIGMENTS— YELLOW, BLUE, AND GREEN PIGMENTS— THE INERT FILLERS AND EX-
TENDERS—PAINT VEHICLES— SPECIAL PAINTS— ANALYTICAL— APPENDIX.
PAPER'MAKING. A Practical Manual for Paper Makers and
Owners and Managers of Paper Mills. With Tables, Calculations,
etc. By G. CLAPPERTON, Paper Maker. With Illustrations of Fibres
from Microphotographs. Second Edition, Revised and Enlarged.
Crown 8vo, cloth ... ... ... ... [Just Published. Net 55.
CHEMICAL AND PHYSICAL CHARACTERISTICS OF VARIOUS FIBRES— CUTTING AND BOILING OF
RAGS — JUTE BOILING AND BLEACHING — WET PICKING — WASHING, BREAKING, AND BLEACHING —
ELECTROLYTIC BLEACHING— ANTICHLOR— CELLULOSE FROM WOOD— MECHANICAL WOOD PULP-
ESPARTO AND STRAW — BEATING — LOADING— STARCHING— COLOURING MATTER — RESIN, SIZE, AND
SIZING — THE FOURDRINIER MACHINE AND ITS MANAGEMENT — ANIMAL SIZING — DRYING — GLAZING
AND BURNISHING— CUTTING, FINISHING— MICROSCOPICAL EXAMINATION OF PAPER— TESTS FOR
INGREDIENTS OF PAPER — RECOVERY OF SODA— TESTING OF CHEMICALS — TESTING WATER FOR
IMPURITIES.
"The author caters for the requirements of responsible mill hands, apprentices, etc., whilst his
manual will be found of great service to students of technology, as well as to veteran papermakers
and mill owners. The illustrations form an excellent feature."— The Worlds Paper Trade.
PAPER-MAKING* A Practical Handbook of the Manufacture
of Paper from Rags, Esparto, Straw, and other Fibrous Materials.
Including the Manufacture of Pulp from Wood Fibre, with a Description
of the Machinery and Appliances used. To which are added Details
of Processes for Recovering Soda from Waste Liquors. By A. WATT.'
With Illustrations. CrownSvo 75. 6d.
CELLULOSE — MATERIALS USED IN PAPER-MAKING — TREATMENT OF RAGS, ESPARTO, WOOD,
AND VARIOUS FIBRES — BLEACHING OR REFINING — LOADING — SIZING — COLOURING — MAKING PAPER
BY HAND AND MACHINERY — CALENDERING, CUTTING, AND FINISHING — COLOURED PAPERS — MIS-
CELLANEOUS PAPERS — MACHINERY USED IN PAPER-MAKING — RECOVERY OF SODA FROM SPENT
LIQUORS— DETERMINING THE REAL VALUE OR PERCENTAGE OF COMMERCIAL SODAS, CHLORIDE OF
LIME, ETC. — USEFUL NOTES AND TABLES— LIST OF WORKS RELATING TO PAPER MANUFACTURE.
" It may be regarded as the standard work on the subject. The book is full of valuable informa-
tion. 'The Art of Paper-Making' is in every respect a model of a text-book, either for a technical
class or for the private student." — Paper and Printing Trades Journal.
12 CROSBY LOCKWOOD & SON'S CATALOGUE.
PAPER-MAKING, CHAPTERS ON. A Series of Volumes dealing
in a practical manner with all the leading questions in connection with
the Chemistry of Paper-Making and the Manufacture of Paper. By
CLAYTON BEADLE, Lecturer on Paper-Making before the Society of
Arts, 1898 and 1902, and at the Battersea Polytechnic Institute, 1902,
•etc., etc. Each volume is published separately, at the price of 55. net
per vol.
Volume I. comprises a Series of Lectures delivered on behalf of
the Battersea Polytechnic Institute in 1902. Crown 8vo. Net 55.
CONTENTS': — EXAMINATION OF FIBROUS RAW MATERIALS FOR PAPER-MAKING—ART PAPERS
AS APPLIED TO PROCESS PRINTING— BLEACHING — CHEMISTRY OF BLEACHING — THE INFLUENCE OF
MOISTURE ON PAPER — CHEMICAL RESIDUES IN PAPER — THE FUNCTION OF WATER IN THE FORMA-
TION OF A WEB OF .PAPER — THE PERMANENCE OF PAPER— SUNDRY PHYSICAL QUALITIES OF
PAPER.
Volume II. comprises Answers to Questions on Paper-Making
Set by the Examiners to the City and Guilds of London Institute,
1901-1903. Crown 8vo, 174 pp Net 55.
CONTENTS : — TECHNICAL EDUCATION AS APPLIED TO PAPER-MAKING — THE USE OF
SPECIALLY PREPARED SIZE IN DRY SHEETS FOR PAPER SIZING — ANSWERS TO ORDINARY AND
HONOURS GRADE EXAMINATION PAPERS, 1901-1903, DEALING WITH SUCH SUBJECTS AS MEASURING
THICKNESS OF PAPERS — INSTRUCTION TO BEATER MEN — ESTIMATION OF DIFFERENT FIBRES —
WASTE PRODUCTS— MANUFACTURE OF ES WRITINGS— TREATMENT OF SPANISH ESPARTO — MANU-
FACTURE OF ART PAPRRS — RAG BOILING— LOADING — COLOURING — PERMANGANATE BLEACHING —
SODA RECOVERING— CHROMO PAPER — ELECTRIC DRIVING IN MILLS — CLASSIFICATION OF RAW
MATERIALS — FORCED DRAUGHT — MECHANICAL STOKING, ETC., ETC.
Volumes III. and IV. embrace upwards of thirty leading practical
questions in connection with the Manufacture of Paper, and the
opinions and answers to these questions by more than fifty mem-
bers of the paper trade occupying positions as Mill Managers,
Machine-men, Beater-men, etc. Against each of these answers are
to be found the author's comments and criticisms, the whole with
Index forming useful book of reference. Just ready. Crown 8vo.
Price 55. net per volume.
Volume III. will discuss the following questions : —
"BRASS" AND "STEEL" BEATER BARS — THE SIZE AND SPEED OF BEATER ROLLS— THE
FADING OF PRUSSIAN BLUE PAPERS— THE EFFECT OF LOWERING THE "BREST" ROLL— THE
EFFECT OF "LOADING" ON THE TRANSPARENCY OF PAPER — "TERRA ALBA" AS A LOADING FOR
PAPER— THE USE OF ALUM IN TUB SIZEING— THE INFLUENCE OF TEMPERATURE IN BLEACHING—
THE USE OF " REFINING" ENGINE — AGITATION AS AN AUXILIARY TO BLEACHING — THE HEATING
OF STUFF FOR THE PAPER MACHINE — THE COMPARATIVE MERITS OF SODA RECOVERY PROCESSES —
THE ELECTRIFICATION OF PAPER ON THE MACHINE — THE COMPARATIVE TRANSPARENCY OF
PAPERS — THK "LIFE" OF MACHINE WIRES— THE ACTION OF EDGE-RUNNERS — THE BULKING
OF PAPERS.
Volume IV. will comprise the following : —
SPECIAL QUALITIES OF "ART" PAPERS— THE "AGEING" OF PAPERS— THE USE OF LIME IN
BOILING — CONTROLLING THE MARK OF THE "DANDY" — THE COMPARATIVE MERITS OF "MA-
CHINE" AND "HAND" CUT RAGS — THE CAUSE OF FROTH ON THE MACHINE AND HARM
RESULTING THEREFROM — THE AMOUNT OF WATER REQUIRED IN THE PRODUCTION OF DIFFERENT
KINDS OF PAPER — THE MANAGEMENT OF SUCTION-BOXES — THE CONTROL OF SHRINKAGE OF
PAPERS ON THE MACHINE — How TO MAKE PAPER THAT DOES NOT SHRINK OR EXPAND WITH
ATMOSPHERIC INFLUENCES — How TO MAKE PAPER THAT DOES NOT STRETCH WHEN TESTING FOR
STRENGTH — GENERAL CONSIDERATIONS OF THE FOREGOING QUESTIONS — USE OF DIFFERENT
PAPER TESTING MACHINES.
TRADES & MANUFACTURES, THE INDUSTRIAL ARTS, ETC. 13-
PARA RUBBER* ITS CULTIVATION AND PREPARATION.
By W. H. JOHNSON, F.L.S., F.R.H.S., Director of Agriculture,.
Gold Coast Colony, West Africa, Commissioned by Government in 1902
to visit Ceylon to Study the Methods employed there in the Cultivation
and Preparation of Para Rubber and other Agricultural Staples for
Market, with a view to Introduce them into West Africa. Demy 8vo, cloth
Net ?s. 6d.
THE PARA RUBBER TREE (Hevea brasiliensis) AT HOME AND ABROAD — CULTIVATION —
PROPAGATION — SITE FOR PLANTATION — DISTANCE APART TO PLANT THE TREES — TRANSPLANT-
ING— CULTIVATION — INSECT PESTS AND FUNGOID DISEASES — COLLECTING THE RUBBER —
VARIOUS METHODS — TAPPING— FLOW OF LATEX INCREASED BY WOUNDING THE TREE — How
TO TAP— THE PREPARATION OK RUBBER FROM THE LATEX— VARIOUS METHODS— SCRAP RUBBER —
YIELD FROM CULTIVATED TREES — ESTABLISHMENT AND MAINTENANCE OF A PARA RUBBER
PLANTATION — COMMERCIAL VALUE OF THE OIL IN HEVEA SEEDS.
PASTRYCOOK AND CONFECTIONER'S GUIDE. For
Hotels, Restaurants, and the Trade in General, adapted also for Family
Use. By R. WELLS, Author of "The Bread and Biscuit Baker." is.
PETROLEUM. THE OIL FIELDS OF RUSSIA AND THE
RUSSIAN PETROLEUM INDUSTRY. A Practical Handbook on
the Exploration, Exploitation, and Management of Russian Oil Pro-
perties, the Origin of Petroleum in Russia, the Theory and Practice of
Liquid Fuel, and a Translation of the Rules and Regulations concerning"
Russian Oil Properties. By A. B. THOMPSON, A.M.I.M.E. 500 pp.?
with numerous Illustrations and Photographic Plates, and a Map of
the Balakhany-Saboontchy-Romany Oil Field. Super-royal 8vo, cloth
Net £3 35.
" A careful and comprehensive study of the conditions of the industry. The work is very
valuable and should undoubtedly be the standard authority on Baku for some time to come." —
Mining Jou rnal.
PIGMENTS* AN ARTISTS' MANUAL. Showing their Composition
Conditions of Permanency, Non-Permanency, and Adulterations, etc.,
with Tests of Purity. By H. C. STANDAGE. Third Edition. Crown
8vo, cloth 2s. 6d.
RECIPES, FORMULAS AND PROCESSES, TWEN-
TIETH CENTURY BOOK OF. Edited by GARDNER D. Hiscox,
M.E. Nearly 10,000 Scientific, Chemical, Technical and Household
Recipes, Formulas and Processes for Use in the Laboratory and the
Office, the Workshop and the Home. Medium 8vo, 800 pp., cloth
Net i2s. 6d.
SELECTED LIST OF CONTENTS. — ABSINTHE — ACID PROOFING — ADHESIVES— ALCOHOL —
ALKALI — ALLOYS — ALUMINIUM — AMMONIA — ANILINE — ANTIDOTES FOR POISON — ANCHOV
PREPARATIONS — ANTISEPTICS — ANTIQUES — BAKING POWDERS — BAROMETERS — BEVERAGES —
BLEACHING — BRASS — BRICK —CARBOLIC ACIDS — CASTING — CELLULOID — CHEESE — CERAMICS —
CIGARS — COFFEE — CONDIMENTS — COPPER — COSMETICS — COTTON — DIAMOND TESTS— DONARITE —
DYES— ELECTRO PLATING— EMBALMING— ENAMELLING— ENGRAVING— ESSENCES— EXPLOSIVES-
FERTILISERS — FILTERS — FOOD ADULTERANTS — GELATINE — GLASS — GOLD — GUMS —HARNESS
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LAUNDRY PREPARATIONS — LEATHER — LINOLEUM — LUBRICANTS — MATCHES — METALS — Music
BOXES — OILS — PAINTS— PAPEK — PERFUMES — PETROLEUM — PHOTOGRAPHY — PLASTER — PLATING —
POLISHES — PORCELAIN — POULTRY — PUTTY — RAT POISONS — REFRIGERATION — ROPES — RUBBER —
RUST PREVENTIVES— SALT— SCREWS— SJLK— SILVER— SOAPS— SOLDERS— SPIRIT— SPONGES— STEEL
— STONE — THERMOMETERS — TIN — VALVES — VARNISHES — VETERINARY FORMULAS— WATCH-
MAKERS' FORMULAS — WATERPROOFING — WAX — WEIGHTS AND MEASURES — WHITEWASH — WOOD
—YEAST.
I4 CROSBY LOCKWOOD & SOX'S CATALOGUE.
RUBBER HAND STAMPS. And the Manipulation of Rubber.
A Practical Treatise on the Manufacture of Indiarubber Hand Stamps,
Small Articles of Indiarubber, The Hektograph, Special Inks, Cements,
and Allied Subjects. By T. O'CoNOR SLOANE, A.M., Ph.D. With
numerous Illustrations. Square 8vo, cloth 55.
SAVOURIES AND SWEETS. Suitable for Luncheons and
Dinners. By Miss M. L. ALLEN (Mrs. A. MACAIRE), Author of
" Breakfast Dishes," etc. Thirtieth Edition. F'cap 8vo, sewed. is.
SEWING MACHINERY. Construction, History, Adjusting, etc.
By J. W. URQUHART. Crown 8vo as.
SHEET METAL-WORKER'S GUIDE. A Practical Handbook
for Tinsmiths, Coppersmiths, Zincworkers, etc., with 46 Diagrams and
Working Patterns. By W. J. E. CRANE. Crown 8vo, cloth. is. 6d.
SHEET METAL WORKER'S INSTRUCTOR. Comprising
Geometrical Problems and Practical Rules for Describing the Various
Patterns required by Zinc, Sheet-Iron, Copper, and Tin-Plate Workers.
By R. H. WARN. New Edition, Revised and Enlarged, by J. G. HORNER,
A.M.I.M.E. Crown 8vo, 254 pp., with 430 Illustrations, cloth 75. 6d.
SILVERSMITH'S HANDBOOK. Alloying and Working of
Silver, Refining and Melting, Solders, Imitation Alloys, Manipulation,
Prevention of Waste, Improving and Finishing the Surface of the Work,
etc. By GEORGE E. GEE. Fourth Edition, Revised. Crown 8vo, cloth. 3s.
SOAP-MAKING. A Practical Handbook of the Manufacture of
Hard and Soft Soaps, Toilet Soaps, etc. With a Chapter on the Re-
covery of Glycerine from Waste Leys. By ALEXANDER WATT. Seventh
Edition, including an Appendix on Modern Candlemaking. Crown 8vo,
cloth 75. 6d.
" The work will prove very useful, not merely to the technological student, but to the practical
soap boiler who wishes to understand the theory of his art." — Chemical News.
SOAPS, CANDLES AND GLYCERINE. A Practical Manual
of Modern Methods of Utilisation of Fats and Oils in the Manufacture
of Soap and Candles, and of the Recovery of Glycerine. By L. L. LAM-
BORN, Massachusetts Institute of Technology, M.Am.C.S. Medium
8vo, cloth. Fully illustrated. 706 pp. ... [Just Published. Net 305.
THE SOAP INDUSTRY — RAW MATERIALS— BLEACHING AND PURIFICATION OF SOAP-STOCK —
THE CHEMICAL CHARACTERISTICS OF SOAP-STOCK AND THEIR BEHAVIOUR TOWARDS SAPONI-
FYING AGENTS— MECHANICAL EQUIVALENT OF THE SOAP FACTORY— COLD PROCESS AND SEMI-
BOILED SOAP — GRAINED SOAP — SETTLED ROSIN SOAP — MILLED SOAP-BASE — FLOATING SOAP
—SHAVING SOAP— MEDICATED SOAP— ESSENTIAL OILS AND SOAP PERFUMERY— MILLED SOAP-
CANDLES— GLYCERINE — EXAMINATION OF RAW MATERIALS AND FACTORY PRODUCTS.
SOLUBILITIES OF INORGANIC AND ORGANIC
SUBSTANCES. A Hand-book of the most Reliable Quantitative
Solubility Determinations. Recalculated and Compiled by ATHERTON
SEIDELL, Ph.D., Chemist, Hygienic Laboratory, U.S., Public Health
Service, Washington, D.C. Medium 8vo, 370 pages.
[Just published. Net 145.
TRADES & MANUFACTURES, THE INDUSTRIAL ARTS, ETC. 15
TEA MACHINERY AND TEA FACTORIES. Describing
the Mechanical Appliances required in the Cultivation and Preparation
of Tea for the Market. By A. J. WALLIS-TAYLER, A.M.lnst.C.E.
Medium 8vo, 468 pp. With 218 Illustrations ...... Net 255.
" The subject of tea machinery is now ne of the first interest to a large class of people to whom
we strongly commend the volume." — Chamber of Commerce Journal.
WAGES TABLES. At 54, 52, 50, and 48 Hours per Week.
Showing the Amounts of Wages from one-quarter of an hour to sixty-four
hours, in each case at Rates of Wages advancing by One Shilling from
4-r. to 55^. per week. By THOS. CARBUTT, Accountant. Square crown
8vo, half-bound ........................ 6s.
WATCH REPAIRING, CLEANING, AND ADJUSTING. A
Practical Handbook dealing with the Materials and Tools used, and
the Methods of Repairing, Cleaning, Altering, and Adjusting all kinds
of English and Foreign Watches, Repeaters, Chronographs, and Marine
Chronometers. By F. J. GARRARD, Springer and Adjuster of Marine
Chronometers and Deck Watches for the Admiralty. With over
200 Illustrations. Crown 8vo, cloth Net 45. 6d.
WATCHES & OTHER TIME-KEEPERS, HISTORY OF.
By J. F. KENDAL, M.B.H.Inst. ... is. 6d. boards; or cloth, 2s. 6d.
WATCHMAKER'S HANDBOOK. Intended as a Workshop
Companion for those engaged in Watchmaking and the Allied Mechanical
Arts. Translated from the French of CLAUDIUS SAUNIER, and enlarged
by JULIEN TRIPPLIN, F.R.A.S., and EDWARD RIGG, M.A., Assayer in
the Royal Mint. Fourth Edition. Crown 8vo, cloth ps.
"Each part is truly a treatise in itself. The arrangement is good and the language is clear
and concise. It is an admirable guide for the young watchmaker." — Engineering.
WEIGHT CALCULATOR. Being a .Series of Tables upon
a New and Comprehensive Plan, exhibiting at one Reference the
Exact Value of any Weight from i Ib. to 15 tons, at 300 Progressive
Rates, from id. to i6Ss. per cwt., and containing 186,000 Direct Answers,
which, with their Combinations, consisting of a single addition (mostly to
be performed at sight), will afford an aggregate of 10,266,000 Answers ; the
whole being calculated and designed to ensure correctness and promote
despatch. By HENRY HARBEN, Accountant. Sixth edition, carefully
Corrected. Royal 8 vo, strongly half-bound £155.
"A practical and useful work of reference for men of business generally." — Ironmonger.
" Of priceless value to business men." — Sheffield Independent.
WOOD ENGRAVING. A Practical and Easy Introduction to
the Study of the Art. By W. N. BROWN. Crown 8vo, cloth. is. 6d.
16 CROSBY LOCKWOOD &• SON'S CATALOGUE.
HANDYBOOKS FOR HANDICRAFTS.
By PAUL N. HASLUCK.
Author of" Lathe Work,-'3 etc. Crown 8vo, 144 pp., is. each.
>*" These Handybooks have been written to supply information for
Workmen, Students, and Amateurs in the several Handicrafts, on the
actual practice of the Workshop, and are intended to convey in plain
language Technical Knowledge of the several Crafts. In describing the
processes employed, and the manipulation of material, workshop terms are
used, workshop practice is fully explained, and the text is freely illustrated
with drawings of modern tools, appliances, and processes.
METAL TURNER'S HANDYBOOK, A Practical Manual
for Workers at the Foot-Lathe. With 100 Illustrations is.
" The book displays thorough knowledge of the subject." — Scotsman.
WOOD TURNER'S HANDYBOOK. A Practical Manual for
Workers at the Lathe. With 100 Illustrations is.
" We recommend the book to young turners and amateurs." — Mechanical World.
WATCH JOBBER'S HANDYBOOK* A Practical Manual
of Cleaning, Repairing, and Adjusting. With 100 Illustrations ... is.
" All connected with the trade should acquire and study this work." — Clerkenwell Chronicle.
PATTERN MAKER'S HANDYBOOK. A Practical Manual
on the Construction of Patterns. With 100 Illustrations ... is.
"A most valuable, if not indispensable, manual for the pattern maker." — Knowledge.
MECHANIC'S WORKSHOP HANDYBOOK. A Practical
Manual on Mechanical Manipulation, embracing Information on various
Handicraft Processes, with Useful Notes and Miscellaneous Memoranda.
Comprising about 200 subjects is.
" Should be found in every workshop, and in all technical schools." — Saturday Review.
MODEL ENGINEER'S HANDYBOOK. A Practical Manual
on the Construction of Model Steam Engines. With upwards of 100
Illustrations ;.. is.
" Mr. Hasluck has produced a very good little book." — Builder.
CLOCK JOBBER'S HANDYBOOK. A Practical Manual on
Cleaning, Repairing, and Adjusting. With 100 Illustrations ... is.
" It is of inestimable service to those commencing the trade." — Coventry Standard.
CABINET WORKER'S HANDYBOOK. A Practical Manual
on the Tools, Materials, Appliances, and Processes employed in Cabinet
Work. With upwards of loo Illustrations is.
"Amongst the most practical guides for beginners in cabinet work." — Saturday Review.
WOODWORKER'S HANDYBOOK. Embracing Information
on the Tools, Materials, Appliances, and Processes Employed in Wood-
working. With 104 Illustrations is.
"Written by a man who knows not only how work ought to be done, but how to do it and how to
convey his knowledge to others." — Engineering.
" Mr. Hasluck writes admirably, and gives complete instructions." — Engineer.
" Mr. Hasluck combines the experience of a practical teacher with the manipulative skill and
scientific knowledge of processes of the trained mechanician, and the manuals are marvels of what can
be produced at a popular price." — Schoolmaster.
" Helpful to workmen of all ages and degrees of experience."— Daily Chronicle.
14 DAY USE
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