174 On a newfulminating Mercury. 



(by predifpofing afBnity) favour, as well as attraft, an acid combination, of the hydrogen 

 of the one, and the oxygen of the other. The pure red oxide of mercury appeared not 

 unfit for this purpofe ; il was therefore intermixed with alcohol, and upon both, nitric acid 

 was afFufed. The acid did not aft upon the alcohol fo immediately as when thefe fluids 

 are alone mixed together, but firft gradually diflblved the oxide : however, after fome 

 minutes had elapfed, a fmell of ether was perceptible, and a white denfe fmoke, much 

 rcfembling that from the liquor fumaus of Libavius, was emitted with ebullition. The 

 mixture then drew down a dark-coloured precipitate, which by degrees became nearly 

 white. This precipitate I feparated by filtration : and, obferving it to be cryftallized in 

 fmall acicular cryftals, of a faline tafte, and alfo finding a part of the mercury volatilized in 

 the white fumes, I muft .acknowledge I was not altogether without hopes that muriatic 

 acid had been formed, and united to the mercurial oxide. I therefore, for obvious 

 reafons, poured fulphuric acid upon the dried cryftalline mafs, when a violent eiFervefcence 

 cnfued, and, to my great aftonilhment, an explofion took place. 



The Angularity of this explofion induced me to repeat the procefs fcveral 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 have the honour to relate in this 

 paper. 



SECTION III. 



I firft attempted to make the mercurial powder fulminate by concuflion ; and for that 

 purpofe laid about a grain of it upon a cold anvil, and ftruck it v/ith a hammer, likewife 

 cold: it detonated llightly, not being, as I fuppofe, ft:ruck with a flat blow ; for, upon 

 ufing 3 or 4 grains, a very (tunning difagreeable nolfe was produced, and the faces both of 

 the hammer and the anvil were much indented. 



Half a grain or a grain, if quite dry, is as much as ought to be ufed on fuch an occafion. 



The fhock of an eleftrical battery, fent through 5 or 6 grains of the powder, produces a 

 very fimilar efl^ed : it feeras indeed, that a (Irong eleftrical fhock, generally acts on ful- 

 minating fubftances like the blow of a hammer. Meflrs. Fourcroy and Vauquelin found 

 this to be the cafe with all their mixtures of oxymuriate of potafli *. 



To afcertain at what temperature the mercurial powder explodes, 2 or 3 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. 



Defirous of co'mparing the ftrenglh of the mercurial compound with that of gunpowder, 

 I made the following experiment, in tlie prefence of my friend Mr. Abernethy. 



• Annalei de Chimie, tom. xxi. p. 13-9. 



Finding 



