420 1EXPERIMENTS on 



found to have lofl in point of purity ; fometlmes no dimi- 

 nution of bulk whatever took place. 



The following circumftances feemcd to influence the laft 

 mentioned experiments, i ft. Temperature. 2d. The length 

 of time during which they were continued. And 3d. The 

 proportion which the mud and air bore to each other, the 

 furface of the mud being more or lefs extenfive, feemcd alfo 

 to have its eifedls. 



The air thus afFeded by the adtion of the mud would in 

 no inftance burn or explode, when a candle v/as applied to 

 it ; hence it contained but a fmall quantity of hydrogen gas. 



This laft mentioned fa£l induced me to engage in an ef- 

 fay to determine the origin of the hydrogen gas which 

 abounds in the air obtained by agitating Jlagnant -waters. 



It is neceffary to be obferved, that in the above experi- 

 ments with mud, but a fmall proportion of water was ad- 

 ded to it in the tumbler, the quantity was juft fufficient to 

 promote putrefaftion. I am of opinion that the hydrogen 

 gas is afforded by a decompofition of the ftagnant w^ater, 

 effedted by the putrefaction of the dead animal and vegeta- 

 ble fubftances, which enter largely into the compofition of 

 the foil of marfhes. 1 was induced to form this opinion, 

 becaufe, firft, pure water is a compound of but two elements, 

 confequently the affinity cannot be broken but by the ac- 

 tion of a third fubftance. And fecondly, we have no ex- 

 periments which prove that pure water has undergone fpon- 

 taneous decompofition. My ideas are confirmed by a fadt 

 well known to all feamen, viz. when a candle is applied to 

 the bung hole of a cafk containing river ivater^ which had 

 been for fome time clofely flopped, an elaftic fluid efcapes, 

 which will inflame and appears in all refpeds fmiilar to hy- 

 drogen gas obtained by other means. 



After forming the above conjectures, I determined to 

 perform a few experiments which might tend to confirm 

 or difprove my opinion. With this view mud and water, 



with 



