SMOKELESS GUNPOWDER.
By HUDSON MAXIM.
During the last forty years leading chemists have continued to experiment with a view to the production of a gunpowder which should be smokeless. But not until the last few years has any considerable degree of success been attained.
To be smokeless, a gunpowder must yield only gaseous products of combustion. None of the so-called smokeless powders are entirely smokeless, although some of them are very nearly so.
The smoke of common black gunpowder is largely due to minute particles of solid matter which float in the air. About one-half of the total products of combustion of black gunpowder of ordinary composition consists of potassium carbonate in a finely divided condition and of potassium sulphate, which is produced chiefly by the burning in the air of potassium sulphide, another production of combustion, as on the outrushing gases it is borne into the air in a fine state of division.
Another cause for the smoke of gunpowder is the formation of small liquid vesicles which condense from some of the products of combustion thrown into the air in a state of vapor, in the same manner as vesicles of aqueous vapor form in the air on the escape of highly heated steam from the whistle of a locomotive.
Broadly speaking, an explosive compound is one which contains, within itself, all the elements necessary for its complete combustion, and whose heated gaseous products occupy vastly more space than the original compound. Such compound usually consists of oxygen, associated with other elements, for which it has great affinity, and from which it is held from more intimate union, or direct chemical combination, under normal conditions, by being in combination as well with other elements for which it has less affinity, but which it readily gives up for the stronger affinities when explosion takes place, the other elements either combining with one another to form new compounds or being set free in an uncombined state.
An explosive is said to detonate when the above changes take place instantaneously, the action being transmitted with the speed of electricity by a sort of molecular rhythm from molecule to molecule throughout the entire substance of the compound.
An explosive is said to explode when the above changes do not occur instantaneously throughout the whole substance, but whose combustion takes place from the surface inward of the particles or grains of which it is composed, thus requiring some definite lapse of time.