n of some oxygen-bearing element, various oxygen-bearing salts
were combined with it, such as nitrate of potassium, nitrate of ammonia,
nitrate of baryta, etc. Also a great many of the first smokeless powders
were made of low grade gun-cotton combined with nitro-glycerine in
varying proportions. These powders would often give very good results
when first made; but low grade gun-cotton or di-nitro-cellulose, as it
is called, is a very unstable compound, and these powders, after giving
very promising results, were found to be constantly undergoing change,
sooner or later resulting in complete decomposition.

When nitro-glycerine was first combined with gun-cotton in small
quantities, camphor was often added, to lessen the rapidity of
combustion which the nitro-glycerine was supposed to impart and also to
render the compound more plastic, and to tend to prevent the
decomposition of the low grade gun-cotton. But camphor being volatile,
would, by its evaporation, cause the powder to constantly change in
character. Castor oil has been found to be a better diluent, as this
will not evaporate.

As all of the smokeless powders made of a low grade gun-cotton were
found to deteriorate and spoil, experiments were made with gun-cotton of
the highest degree of nitration, both alone and in combination with
nitro-glycerine. These experiments were first conducted in England by
private parties and by the British government, when it was found that
high grade gun-cotton would give excellent results if made into a
colloidal solid and used alone, or in combination with certain other
constituents. With a view to saving the large quantity of solvents
necessary to reduce the gun-cotton, and to get a more prompt and certain
ignition with a larger grain, experiments were cautiously made by the
admixture of varying proportions of nitro-glycerine to the gun-cotton
when dissolved, or rather along with other solvents in the process of
dissolving it.

It was soon found that nitro-glycerine added in quantities, even equal
in weight to the gun-cotton itself, did not materially increase the
rapidity of the explosion of the compound. And it was also found that
high grade gun-cotton, when combined with nitro-glycerine, gave very
much better results than low grade gun-cotton.

I have spoken here of high and low grade gun-cotton, when in fact the
word gun-cotton should be applied only to the highest nitro-compound of
cellulose. The word gun cotton has al