Nitro-Explosives: A Practical Treatise | Page 3

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 NO_{2} group, known as nitryl, has been substituted in
place of hydrogen.
Thus in glycerine,
|OH C_{3}H_{5}|OH, |OH
which is a tri-hydric alcohol, and which occurs very widely distributed
as the alcoholic or basic constituent of fats, the hydrogen atoms are
replaced by the NO_{2} group, to form the highly explosive compound,
nitro-glycerine. If one atom only is thus displaced, the mono-nitrate is
formed thus,

|ONO_{2} C_{3}H_{5}|OH; |OH
and if the three atoms are displaced, C_{3}H_{5}(ONO_{2})_{3}, or
the tri- nitrate, is formed, which is commercial nitro-glycerine.
Another class, the nitro-celluloses, are formed from cellulose,
C_{6}H_{10}O_{5}, 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,
C_{12}H_{14}O_{4}(ONO_{2})_{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 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, C_{6}H_{6}, prepared from the light oil obtained from
coal-tar, when nitrated forms nitro-benzenes, such as
mono-nitro-benzene, C_{6}H_{5}NO_{2}, and di-nitro-benzene,
C_{6}H_{4}(NO_{2})_{2}, in which one and two atoms are replaced
by the NO_{2} group. The latter of these compounds is used as an
explosive, and enters into the composition 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,
C_{6}H_{4}X_{2}, give, however, three series. They are called ortho,
meta, or para compounds, depending upon the position of NO_{2}
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 compound 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, C_{6}H_{5}.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.[A]
[Footnote A: "Organic Chemistry," Prof. Hjelt. Translated by J.B.
Tingle, Ph.D.]
If the graphic formula of benzene be represented thus (No. 1), then the
positions 1 and 2 represent the ortho, 1 and 3 the meta, and 1 and 4 the
para compounds. When the body phenol, C_{6}H_{5}.OH, is nitrated,
a compound is formed known as tri-nitro-phenol, or picric acid,
C_{6}H_{2}(NO_{2})_{3}OH, which is used very extensively as an
explosive, both as picric acid and in the form of picrates. Another nitro
body that is used as an explosive is nitro-naphthalene,
C_{10}H_{6}(NO_{2})_{2}, in roburite, securite, and other
explosives of this class. The hexa-nitro- mannite,
C_{6}H_{8}(ONO_{2})_{6}, is formed
[Illustration: No. 1]
[Illustration: META-DINITRO-BENZENE No.2]
by treating a substance known as mannite, C_{6}H_{8}(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.
Muhlhauer has described (_Ding. Poly. Jour._, 73, 137-143) three nitric
ethers of starch, the tetra-nitro-starch,
C_{12}H_{16}O_{6}(ONO_{2})_{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.
Muhlhauer proposes to use this body as a smokeless powder, and to
nitrate it with the spent mixed acids from the manufacture of nitro-
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 by Mühlhäuer. The former
chemists give jute the formula C_{12}H_{18}O_{9}, and believe that
its conversion into a nitro-compound takes place according to the
equation--
C_{12}H_{18}O_{9} + 3HNO_{3} = 3H_{2}O +
C_{12}H_{15}O_(6}(NO_{3})_{3}.
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