On a new fulminating Mercury. f 9. 



|>rocers levcral times; and, finding that I always obtained 

 the fame kind of powder, I prepared a quantity of it, and 

 was led to make the feries of experiments which I fliall havit 

 the honour to relate ia this paper. 



Section III. 



I firft attempted to make the mercurial powder fulminate 

 by concuffion ; and for that purpole laid about a grain of M 

 upon a cold anvil, and ftruck it with a hammer, likewife 

 cold : it detonated flighlly, not being, as I fuppofe, ftruck 

 with a flat blow ; for, vipon ufing three or four grains, a 

 very ftunning difagreeable noife was produced, and the faces 

 both of the hammer and the anvil were much indented. 



Haifa grain, or a grain, if quite dry, is as much as ought 

 to be ufed on fucb an occafion. 



The (hock of an eleftrical battery, fent through five or fijfc 

 grains of the powder, produces a very fimilar effeft : it feems, 

 indeed, that a ftrong ele6trical (hock generally a6ls on ful- 

 minating fubftances like the blow of a hammer, MefTrs. 

 Fourcroy and Vauquelin found this to be the cafe with ail 

 their mixtures of oxymuriat of potafli *. 



To afcertain at what temperature the mercurial powder 

 explodes, two or three grains of it were floated on oil, in a 

 capfule of leaf tin ; the bulb of a Fahrenheit's thermometer 

 was made juft to touch the furface of the oil, which was then 

 gradually heated till the powder exploded, as the mercury of 

 the thermometer reached the 368th degree. 



Section IV. 



De(irous of comparing the ftrength of the mercurial com- 

 pound with that of gunpowder, I made the following expe- 

 riment, in the prefence of my friend Mr. Abernethv. 



Finding that the powder could be fired by flint and ftcel, 

 without a difagreeable noife, a common gunpowder proof, 

 capable of containing eleven grains of fine gunpowder, was 

 filled with it, and fired in the ufual way : the report was 

 (harp, but not loud. The perfon who held the inlirumcnt 

 ia his haad felt no recoil ; but the explofion laid open the 



"* Aarsilcs de Cbimir, Tom. XXI, p. 239, 



t) 2, upper 



