X. Contributions to the history of explosive agents. —Second memoir

Abstract

Since the publication of the experiments on the explosion of gun-cotton and other compounds and mixtures by detonation, which are detailed in a memoir submitted by me to the Royal Society in March 1869, this matter has received considerable practical development, and has also been made the subject of further scientific investigation, both in England and on the Continent. In continuing my researches into the conditions to be fulfilled for accomplishing the detonation of explosive substances, I have arrived at further results confirmatory of, and additional to, those described in my former memoir. I have also been led to pursue experiments bearing upon this subject in somewhat new directions; and I venture to believe that an account of the results arrived at may possess some value as tending to throw further light upon the behaviour and properties of explosive agents. The exceptional behaviour which I have described as being exhibited by certain explosive compounds when applied to the development of detonation, in comparison with other substances, to which they were not inferior as regards the force and heat developed by their explosion, has been confirmed by further experiment. It was stated by me that 0·32 grm. (5 grains) of mercuric fulminate, if applied under favourable conditions, suffice to develop the detonation of compressed gun-cotton, that 3·25 grms. (50 grains) of chloride of nitrogen appeared to be the minimum amount by which detonation of gun-cotton could be developed, that 6·5 grms. (100 grains) of iodide of nitrogen failed to produce this result, and that repeated trials with different quantities of nitroglycerine ranging up to 31·2 grms. (1 ounce) did not in any one instance result in the detonation of gun-cotton by that substance, although the mechanical force and heat developed by its explosion were at least fully equal to those brought into operation by corresponding quantities of the most violent of the above explosive agents.