Mr. E. Howard on a new fulminating Mercury. 233 



arsenic, and manganese; but I have not yet sufficiently varied 

 my experiments, to enable me to speak with absolute certainty. 

 Silver, when 20 grains of it were treated with nearly the same 

 proportions of nitrous acid and alcohol as 100 grains of mercury, 

 yielded, at the end of the operation, about 3 grains of a gray 

 precipitate, which fulminated with extreme violence. Mr. 

 Cruickshank had the goodness to repeat the experiment : he 

 dissolved 40 grains of silver in 2 ounces of the strongest 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 gray precipitate above described. It 

 probably combines with the same principles as the mercury, and 

 of course differs from Mr. Berthollet's fulminating silver, 

 alluded to in page 230. I observe, that a white precipitate is 

 always produced in the first instance, and that it may be pre- 

 served, by adding water, as soon as it is formed ; otherwise, when 

 the mother liquor is abundant, it often becomes gray, and is 

 re-dissolved. 



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 conjunction with Colonel 

 Blomefield, and Mr. Cruickshank.* 



Experiment 1 . From the manner in which the screw of the gun- 

 breech, mentioned in Section v. had acted on the barrel, it was 

 imagined, that by bursting an iron case, exactly fitted to the 

 bore of a cannon, its sudden enlargement might make many 

 flaws, and split the piece, without dispersing any splinters. In 



* It is with pleasure I take this opportunity of acknowledging the civil attention I 

 received from the different officers. 



MDCCC H h 



