when subject to the action of reducing agents, are
converted into amido compounds, as is the case, for instance, with
nitro-benzene, C{6}H{5}NO{2}, into aniline, C{6}H{5}NH{2}, or with
nitro-naphthalene, C{10}H{7}NO{2}, which changes into naphthylamine,
C{10}H{7}NH{2}.

But the nitric acid derivatives of cellulose are not capable of
conversion by reducing agents into similar amido compounds. They have
the following properties, which accord more closely with nitrates than
with nitric bodies: alkalies remove the nitric acid; cold sulphuric acid
expels the nitric acid, cellulose sulphates being formed; boiling with
ferrous sulphate and hydrochloric acid causes the elimination of the
nitric acid as nitric oxide (on which reaction a method for determining
the degree of nitration of gun cotton is based). It is best therefore to
consider them as cellulose nitrates. Several well-characterised
cellulose nitrates have been prepared, but is an exceedingly difficult
matter to obtain any one in a state of purity, the commercial articles
being always mixtures of two or three. Those that are best known and of
the most importance are the following:--

Cellulose Hexa-nitrate, C{6}H{4}O{5}(NO{3}){6}. This forms the
principal portion of the commercial explosive gun cotton, and is made
when a mixture of strong nitric acid and strong sulphuric acid is
allowed to act on cotton at from 50 to 55 deg. F. for twenty-four hours. The
longer the action is prolonged, the more completely is the cotton
converted into the nitrate, with a short duration the finished product
contains lower nitrates. This hexa-nitrate is insoluble in ether,
alcohol, or in a mixture of those solvents, likewise in glacial acetic
acid or in methyl alcohol.

Cellulose Penta-nitrate, C{6}H{5}O{5}(NO{3}){5}, is found in
explosive gun cotton to a small extent. When gun cotton is dissolved in
nitric acid and sulphuric acid is added, the penta-nitrate is thrown
down as a precipitate. It is not soluble in alcohol, but is so in a
mixture of ether and alcohol, it is also slightly soluble in acetic
acid. Solutions of caustic potash convert it into the di-nitrate.

Cellulose Tetra-nitrate, C{6}H{6}O{5}(NO{3}){4}, and Cellulose
Tri-nitrate, C{6}H{7}O{5},(NO{3}){3}, form the basis of the
pyroxyline or soluble gun cotton of commerce. It has not been found
possible to separate them owing to their behaviour to solvents being
very similar. These nitrates are obtained by treating cotton