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 alone.  The nitro-glycerine, furthermore, being itself a solvent of gun-cotton, much less of the volatile ether is necessary to render the compound of an amorphous character.  Being quite plastic this substance may be wrought or moulded into any desired size or form of grain.

This simple compound of nitro-glycerine and gun-cotton, or with some slight modifications, has been found, when properly granulated, to be the most smokeless powder that has yet been discovered or invented.  If pure chemicals are employed in the manufacture, and the gun-cotton and nitro-glycerine be made of the highest nitration and best quality, we have a smokeless powder which will possess the following desirable qualities: 

1st.  It is absolutely smokeless, that is, its products of combustion are entirely gaseous.

2d.  Its products of combustion are in no way deleterious or unpleasant.

3d.  It is perfectly safe to manufacture, handle and transport.  There is no more danger of its exploding accidentally than there would be of an explosion of shavings or sawdust; for, unless well confined and set off with a strong primer, it will not explode at all.  In the open its combustion is so slow as to in no way resemble or partake of the nature of an explosion.

4th.  It is perfectly stable, and will keep any length of time absolutely without undergoing any change whatever, under all conditions of temperature or exposure to which gunpowder would ever be subjected.

5th.  It is not hygroscopic, and may be soaked in water without being at all affected by it.

6th.  It will not corrode the cartridge case.