On a newfulminatitig Mercury. 25 1 



greater quantity of oxalic acid, from the fame materials, with the intervention of 100 

 grains of mercury, than with the intervention of 100 grains of copper, otherwife than by 

 the notion of confpiring afEnities, fo analogous to what we fee in other phsenomena of 

 nature F 



I have attempted, without fuccefs, to communicate fulminating properties, by means of 

 alcohol, to gold, platina, antimony, tin, copper, iron, lead, zinc, nickel) bifmuth, co- 

 balt, arfenic, and manganefe ; but I have not yet fufEciently varied my experiments, to 

 enable me to fpeak with abfolute certainty. Silver, when 20 gprains of it were treated 

 with nearly the fame proportions of nitrous acid and alcohol as lOO grains of mercury, 

 yielded, at the end of the operation, about 3 grains of a grey precipitate, which fulmi- 

 nated with extreme vio'ence. Mr. Cruickfhank had the goodnefs to repeat the experiment; 

 he diflbived 40 grains of filver in a ounces of the ftrongeft nitrous acid diluted with an 

 equal quantity of water, and obtained (by means of 2 ounces of alcohol) 60 grains of a 

 very white powder, which fulminated like the grey precipitate above defcribed. It pro- 

 bably combines with the fame principles as the mercury, and of courfe differs from Mr. 

 Berthollet's fulminating filver, alluded to in page 250. I obferve, that a white precipitate 

 is always produced in the firft inftance, and that it may be preferved, by adding water, 

 as foon as 5t is formed ; otherwife, when the mother liquor is abundant, it often becomes 

 grey, and is re- diflbived. 



P. S. Since the preceding pages were written, I have been permitted, by the Right 

 Honourable Lord Howe, Lieutenant General of the Ordnance, to make the following 

 trials of the mercurial powder, at Woolwich, in conjundlion with Colonel Blomefield, 

 and Mr. Cruickfliank *. ' 



Experiment i. From the manner in which the fcrew of the gun-breech, mentioned in 

 Se£lion v. had afted on the barrel, it was imagined, that by burfting an iron cafe, exaitly 

 fitted to the bore of a cannon, its fudden enlargement might make many flaws, and fplit 

 the piece, without difperfing any fplinters. In conformity to this opinion, a call iron cafe 

 was conflrufted, with a cylindrical chamber, of equal length and diameter, calculated to 

 hold 3.1 ounces troy of the mercurial powder. The cafe, being firmly fcrewed together, 

 was charged through its vent-hole, and introduced into a twelve-pounder carronade, the 

 bore of which it exaflly fitted. The powder was then enflamed, with proper precautions. 

 -The gun remained entire, but the cafe divided : the portion forming the upper furface of 

 the chamber, was expelled in one mafs; that adjoining the breech, which conftituted the 

 reft of the chamber, was cracked in every dire£tion, and in part crumbled ; yet it was fo 

 wedged into fome indentations which the explofion had made in the fides of the piece, that 

 the fragments were not removed without great labour. 



Experiment 2. Another caft iron cafe was prepared, of the fame fize as the former, with 

 a chamber alfo cylindrical, but wrought in a tranfverfe dire£lion, and of a greater length' 



* It is with pleafure I take this opportunity of acknowledging the civil attention I received from the 

 different officers. 



K k 2 than 



