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



SECTION XVII. 



I will now conclude, by observing, that the fulminating mer- 

 cury seems to be characterised by the following properties. 



It takes fire at the temperature of 368 Fahrenheit; explodes 

 by friction,* by flint and steel, and by being thrown into con- 

 centrate sulphuric acid. It is equally inflammable under the 

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

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

 hammer, and by a strong electrical shock. 



Notwithstanding the composition of fulminating silver, and 

 of fulminating gold, differ essentially from that of fulminating 

 mercury, all three have some 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 inconceivable force : its agents seem to be gas and 

 caloric, very suddenly set at liberty, and both mercury and water 

 thrown into vapour. The other displays a more extended but 

 inferior power: gas and caloric are, comparatively speaking, 

 liberated by degrees; and water, according to Count Rumford, 

 is thrown into vapour.-f* 



Hence it seems, that the fulminating mercury, from the limi- 

 tation of its sphere of action, can seldom if ever be applied to 

 mining ; and, from the immensity of its initial force, cannot be 



* Consequently it should not be inclosed in a bottle with a glass stopper. 



f See Philosophical Transactions, for the year 1797, p. 222. 



The hard black substance mentioned by the Count, as remaining after the com- 

 bustion of gunpowder, must, I believe, have been an alkaline sulphuret, mixed chiefly 

 with sulphite and carbonate of potash. The conjecture that it is white when first' 

 formed, is certainly just, as my experiment with the glass globe evinced. 



