On a new fulminating Mercury, j.a 



gas is producecl, which is evidently a mixture of oxygenons and hydkogetious gafes ; for, 

 when an eledrical fpark is paffed through the gas that remains after the abforption of the 

 carbonic acid by cauftic alkali, it immediately explodes. Thefe refuits even take place on 

 ele(^rifying carbonic acid from marble, prcvioufly calcined in a low red heat, to expel its 

 water, and then diftilled in an earthen retort *. 



III. 



On a New Fubninating Mercury. By Edward Howard^ Efq. F. R, S, 

 C Concluded from page 2ogJ ^ 



SECTION XVII. 



I 



WILL now conclude, by obferving, that the fulminating mercury fcems to be charac- 

 terifed by the following properties : 



It takes fire at the temperature of 368 Fahrenheit; explodes by fri£tion f, by flint and 

 fteel, and by being thrown into concentrate fulphuric acid. It is equally inflammable 

 under the exhaufted receiver of an air-pump, as furrounded by atmofpheric air ; and it 

 detoir.tes loudly, both by the blow of a hammer, and by a ftrong elcftrical (hock. 



Notwithftanding the compofition of fulminating filver, and of fulminating gold, differ 

 eflentially from that of fulminating mercury, all three have fome fimilar qualities. In tre- 

 mendous effefts, filver undoubtedly (lands firft, and gold perhaps the la(t. The effefts of 

 the mercurial powder and of gunpowder, admit of little comparifon. The one exerts,' 

 within certain limits, an almoft inconceivable force : its agents feem to be gas and caloric, 

 very fuddenly fet at liberty, and both mercury and water thrown into vapour. The other 

 difplays a more extended but inferior power : gas and caloric are, comparatively fpeaWng, 

 liberated by degrees : and water, according to Count Rumford, is thrown into vapour t. 



Hence it feems, that the fulminating mercury, from the limitation of its fphere of 

 action, can feldom if ever be applied to mining ; and, from the immenfity of its initial 



♦ Melfieurs Landiiani and Van Maioim (jfnnalesde Chimie, torn. ii. p. 170.) obtained only hydrogencut 

 gas, by eleftrifying the carbonic acid gas. But the conduftor of their apparatus was an iron one ; which 

 metal would combine with the oxygen of the water, and prevent it from appearing in a gafeous ftate. In 

 my experiments, the conduflors were of platina. 



•}• Confe<}uently it Ihould not be inclofed in a botde with a glafs ftopper. 



X See Philofophical TranCaflions, for the year 1797, p. az». , 



The hard black fubftance mentioned by the Count, as remaining after the combuftion of gunpowder, 

 inuft, I believe, have been an alkaline fulphuret, mixed chiefly with fulphite and carbonate of pot-afti. 

 The conjeflure that it is white when firft formed, is certainly juft, as my experiment with the glafs globe 

 evinced. 



Vol. IV.— September 1800. Kfc force, 



