FULMINATING MERCURY. 203 



ducod with certainty, liy the repetition of Dr. Priestlry's cxpori- 

 nifiits, or should it by any means be got pure from the nitrous 

 etherized gass, my curiosity will excite me to make it the object of 

 future research ; otherwise, I must confess, I shall feel more dis. 

 posed to prosecute othi r chemical subjects : for baring reason to 

 think, that the density of the acid made a variation in the product 

 of this gass, and having never found that any acid, however dense, 

 produced an immediate rxplosion, 1 once poured six drachms of 

 concentrate arid upon fifty grains of the powder. An explosion, 

 nearly at the instant of contact, was effected : I was wounded se- 

 verely, and most of my apparatus destroyed. A quantity more, 

 over of the gass I had previously prepared was lost, by the inad. 

 vertency of a person who went into my laboratory, whilst I was 

 confined by the consequences of this discouraging accident Bat 

 should any one be desirous of giving the gass a further examina- 

 tion. I again repeat, that as far as I am enabled to judge, it may 

 with safety be prepared, by pouring three drachms of sulphuric 

 acid, diluted with the same quantity of water, upon fifty grains of 

 the powder, and then applying the flame of a candle until gass 

 begins to be extricated. The only attempt I have made to decom- 

 pose it, was by exposing it to copper and ammonia ; which, during 

 several weeks, did not effect the least alteration. 



" I will now conclude (continues Mr. Howard), by observing, 

 that the fulminating mercury seems to be characterised by the fol- 

 lowing properties : 



" It takes fire at the temperature of 368 Fahrenheit; it ex. 

 plodes by friction, by flint and steel, and by being thrown into 

 concentrate sulphuric acid. It is equally inflammable under the 

 exhausted receiver of an air-pump, as surrounded by atmospheric 

 air ; and it detonates loudly, both by the blow of a hammer, and 

 by a strong electrical shock. 



" Notwithstanding the compositions of fulminating silver, and 

 of fulminating gold, differ essentially from that of fulminating 

 mercury ; all three have similar qualities. In tremendous effects, 

 silver undoubtedly stands first, and gold perhaps the last. The 

 effects of the mercurial powder, and of gunpowder, admit of little 

 comparison. The one exerts, within certain limits, an almost in- 

 conceivable force : its agents seem to be gass and caloric, very 

 suddenly set at liberty, and both mercury and water thrown into 

 vapour. The other displays a more extended, but inferior power : 



