8th. It is sure of ignition with a good primer, and may be made to burn as slowly as desired by varying the character and size of the grains. Indeed, it may be made to burn so slowly as to fail of complete combustion before the bullet leaves the gun, and after firing several rounds, partly burned pieces of the powder may be picked up in front of the gun. 9th. In a shoulder arm, a velocity of 2,000 feet per second may be imparted to the bullet with this powder, and with a pressure in the chamber of the gun of not more than fifteen English tons. This is, of course, when the gun, cartridge case, primer, and projectile are adapted to the use of smokeless powder, and the granulation of the powder is adapted to them. If what I have here claimed for the above smokeless powder be true, it would appear that it may be taken as really an ideal smokeless powder. Why, then, has it not already been universally adopted? Surely such a powder is just what every government is seeking. In reply to this, let me say that, in order for the above compound to be an effective and successful smokeless powder, with the manifestation of the many desirable qualities which I have recited, a great many other conditions are necessary, some of which I will mention. To arrive at the knowledge that this compound would constitute the best smokeless powder has required a great deal of experimenting. It was first thought that gun-cotton colloid, without any nitro-glycerine, that is, gun-cotton dissolved and dried, would burn more slowly, keep better, and give better ballistics than it would if combined with nitro-glycerine. It was also thought that gun-cotton of a high degree of nitration when made into colloidal form would even then burn too quickly to be suitable for use in firearms. Consequently, the first experiments were with low grade gun-cotton, what is called collodion cotton, such as is employed in the manufacture of celluloid. But, as this would not explode without the addition 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.