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



sulphuric acid, and that, by using a dilute instead of a concen- 

 trate acid, a gas is obtained which enlarges the flame of a 

 burning taper, so much like the gaseous oxide of azote, that 

 they mistook it for that substance, until they discovered that it 

 was permanent over water, refused to detonate with hydrogen, 

 and that the fallacious appearance was owing to a mixture of 

 nitrous gas with an inflammable gas. 



The inflammable gas separated from the powder answers to 

 the description of the gas which at first deceived the Dutch 

 chemists; ist, in being permanent over water; 2dly, refusing 

 to detonate with hydrogen; and, 3dly, having the appearance 

 of the gaseous oxide of azote, when mixed with nitrous gas. 



The gas separable by the same acid, from nitrous etherized 

 gas, and from the mercurial powder, have therefore the same 

 properties. Every chemist would thence conclude, that the 

 nitrous etherized gas is a constituent part of the powder, had 

 the inflammable and nitrous gas, instead of the inflammable and 

 carbonic acid gas, been the mixed product extricated from it 

 by dilute sulphuric acid. 



It however appears to me, that nitrous gas was really pro- 

 duced by the action of the dilute sulphuric acid; and that, 

 when produced, it united to an excess of oxygen present in the 

 oxalate of mercury. 



To explain how this change might happen, I must premise, 

 that my experiments have shewn me, that oxalate of mercury 

 can exist in two, if not in three states. 



ist, By the discovery of Mr. Ameilon already quoted, the 

 precipitate obtained by oxalic acid, from nitrate of mercury, fuses 

 with a hissing noise. This precipitate is an oxalate of mercury, 

 seemingly with excess of oxygen. Mercury dissolved in sul- 



