Mr. E. Howard on a new fulminating Mercury. 229 



" contained. In the next produce of air, from the same process, 

 " the flame descended blue and very rapid, from the top to the 

 " bottom of the vessel." 



These greenish and blue coloured flames, descending from 

 the top to the bottom of the vessel, are precisely descriptive of 

 the inflammable gas separated from the powder. If it can be 

 produced with certainty by the repetition of Dr. Priestley's 

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

 nitrous etherized gaSj my curiosity will excite me to make it 

 the object of future research ; otherwise, I must confess, I shall 

 feel more disposed to prosecute other chemical subjects : for, 

 having reason to think that the density of the acid made a varia- 

 tion in the product of this gas, and having never found that any 

 acid, however dense, produced an immediate explosion, I cnce 

 poured 6 drams of concentrate acid upon 50 grains of the 

 powder. An explosion, nearly at the instant of contact, was 

 effected : I was wounded severely, and most of my apparatus 

 destroyed. A quantity moreover of the gas I had previously 

 prepared, was lost by the inadvertency of a person who went 

 into my laboratory, whilst I was confined by the consequences 

 of this discouraging accident. But, should any one be desirous 

 of giving the gas a further examination, I again repeat, that as 

 far as I am enabled to judge, it may with safety be prepared, 

 by pouring 3 drams of sulphuric acid diluted with the same 

 quantity of water, upon 50 grains of the powder, and then 

 applying the flame of a candle until gas begins to be extricated. 

 The only attempt I have made to decompose it, was by ex- 

 posing it to copper and ammoniac; which, during several weeks,, 

 did not effect the least alteration. 



