Gun-cotton, discovered by Schonbein, in 1845, has since been looked upon
as the most promising material for a smokeless gunpowder, it being a
very powerful explosive and burning with practically no smoke. To-day,
gun-cotton, in some form or other, constitutes the base of substantially
all of the smokeless powders with which have been attained any
considerable degree of success.

Gun-cotton alone and in its fibrous state has been found to be too
quick, or violent, for propulsive purposes, such as use in firearms; as
under such conditions of confinement it is very likely to detonate and
burst the gun. However, if gun-cotton be dissolved in a suitable
solvent, which is capable of being evaporated out, such as acetone, or
acetate of ethyl, which are very volatile, it becomes, when thus
dissolved and dried, a very hard, horn-like, amorphous substance, which
may be used for a smokeless gunpowder. But this substance taken alone is
very difficult to mould or granulate, and the loss of expensive solvents
must necessarily be quite considerable.

When gun-cotton is reduced to a collodial solid, as above, and used as a
smokeless gunpowder, the grains must be made comparatively small to
insure prompt and certain ignition, and consequently the pressures
developed in the gun are apt to be too great when charges sufficiently
large are used to give desired velocities.

If, however, a compound be made of gun-cotton and nitro-glycerine, in
about equal parts, by means of a volatile solvent or combining agent,
such as one of the before mentioned, and the solvent evaporated out, we
obtain practically a new substance and one which, as regards its
explosive nature, is quite unlike either of its two constituents taken