Chemical Observations, 355 



that column, and the whole of the second, are derived from 

 my own experiments : — 



One volume of explosive mixture was ren- Effect of adding the same gases to one volume 

 dered incapable of being inflamed by elec- of explosive mixture on the action of the 



tricity when mixed with sponge. 



/ " — \ f T! ' > 



About *8 vols of hydrogen - - not prevented by many vols. 



„ 6 „ nitrogen - - ditto. 



*9 „ oxygen - - - not prevented by 10 vols. 



♦11 „ nitrous oxide - ditto. 



1 .5 „ cyanogen - - prevented by 1 vol. 



*1 „ carbonized hydr. not prevented by 1 vols. 



4 „ carbonic oxide - prevented by \ vol. 



♦0.5 „ defiant gas - - prevented by 1.5 vol. 



*2 „ muriatic acid - not prevented by 6 vols. 



2 „ aramoniacal - not prevented by 10 vols. 



3 „ carbonic acid - ditto." 



From other observations of Dr. Henry, carbonic oxide 

 appears to retard the combustion of hydrogen, by taking the 

 precedence of the latter in uniting with oxygen, from superior 

 inflammability. This I found to be much more strikingly the 

 case with sulphuretted hydrogen gas, which Dr. Turner found 

 to suspend the action of the sponge, when present even in the 

 most minute proportion. When mixed with oxygen, this gas 

 slowly disappeared under the influence of a dried clay pellet, 

 containing spongy platinum ; the hydrogen only uniting with 

 the oxygen, and the sulphur being deposited in the ball, which 

 was soon thereby rendered inactive, but not till it had destroyed 

 two or three hundred times its bulk of sulphuretted hydrogen 

 in the course of twenty-four hours. In a mixture of sulphuretted 

 hydrogen, hydrogen and oxygen gases in equal volumes, the 

 oxygen united in twenty-fours to the hydrogen of the sulphuretted 

 hydrogen, nearly to the entire exclusion of the free hydrogen ; 

 but the union of the last with the remaining oxygen was deter- 

 mined in a few seconds by throwing up a fresh platinum ball. 



Sulphurous acid gas is as efficient in this way as sulphuretted 

 hydrogen (Turner) ; yet, upon trial, the sponge had no effect 

 in determining the union of oxygen and sulphurous acid, even 

 with the presence of moisture. 



Olefiant gas in my hands was at first as powerful in preventing 

 the combustion of explosive mixture as it was found to be by 



