Mr. E. Howard on a new fulminating Mercury. 211 



temperature. It appears therefore, that the ten grains of powder, 

 produced four cubical inches only of air. 



To continue the comparison between the mercurial powder 

 and gunpowder, 10 grains of the best Dartford gunpowder were 

 in a similar manner set fire to in the glass globe : it remained 

 entire. The whole of the powder did not explode, for some 

 complete grains were to be observed adhering to the interior 

 surface of the glass. Little need be said of the nature of the 

 gases generated during the combustion of gunpowder : they 

 must have been, carbonic acid gas, sulphureous acid gas, nitro- 

 gen gas, and (according to Lavoisier*) perhaps hydrogen gas. 

 As to the quantity of these gases, it is obvious that it could 

 not be ascertained ; because the two first were, at least in part, 

 speedily absorbed by the alkali of the nitre, left pure after the 

 decomposition of its nitric acid. 



SECTION VIII. 



From the experiments related in the 4th and 5th sections, in 

 which the gunpowder proof and the gun were burst, it might 

 be inferred, that the astonishing force of the mercurial powder 

 is to be attributed to the rapidity of its combustion ; and, a train 

 of several inches in length being consumed in a single flash, it 

 is evident that its combustion must be rapid. From the expe- 

 riments of the 6th and 7th sections, it is sufficiently plain that 

 this force is restrained to a narrow limit; both because the block 

 of wood charged with the mercurial powder was more shattered 



* See Lavoisier, Trails' dementaire, p. 527. 



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