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.


~The Nitro-Celluloses.~--The substance known as cellulose 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 cellulose
is (C_{6}H_{10}O_{6})_{X}, and it is generally assumed that the molecular
formula must be represented by a multiple of the empirical formula,
C_{12}H_{20}O_{10} 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)
considers these reasons insufficient, and prefers to employ the single
formula C_{6}H_{10}O_{5}. 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.

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:--