426 



Dr. Henri/ on the Action of 



[June; 



1 vol. of explosive mixture was rendered 

 incapable of being inflamed by electri- 

 ' city when mixed with 

 ■ ^ , 



*About 8 vol. of hydrogen 

 6 



* 9 



* 11 



1-5 



* 1 



* 



4 



0-, 



2 



2 



3 



nitrogen. 



oxygen 



nitrous oxide 

 cyanogen. . . 

 carb. hydrog, 

 carbonic ox. 

 defiant gas. . 

 muriatic acid 

 ammonia . . . 

 carbonic acid 



EflPect of adding the same gases to 1 vol. 



of explosive mixture on the action of 



the sponge. 

 I ' > 



not prevented by many vols. 



ditto. 



not prevented by 10 vol. 



ditto. 



prevented by 1 vol. 



not prevented by 10 vol. 



prevented by -^ a vol. 



prevented by 1'5 vol. 



not prevented by 6 vol, 



not prevented by 10 vol. 



ditto. 



From the foregoing table it appears, that carbonic oxide pro- 

 duces the greatest eftect, in the smallest proportion to an explo- 

 sive mixture of oxygen and hydrogen, in preventing the action 

 of those gases on each other, when exposed to the sponge at 

 temperatures below the boiling point of mercury. In general, 

 those gases which either do not unite with oxygen, or unite with 

 it only at high temperatures, have little eftect in restraining the 

 efficiency of the sponge. There is an apparent exception, how- 

 ever, in cyanogen, which it would require more research than I 

 have yet had time to devote to an object merely collateral, to 

 reconcile (if it be capable of being reconciled), with the general 

 principle. 



From the fact that carbonic oxide, olefiant gas, and carbu- 

 retted hydrogen, when brought to unite with oxygen by means 

 of the platinum sponge assisted by heat, undergo this change at 

 different temperatures, it seemed an obvious conclusion, that by 

 exposing a mixture of those gases with each other and with 

 oxygen to a regulated temperature, the correct analysis of such 

 mixtures might probably be accomplished. Mixtures of two or 

 more of the combustible gases were therefore exposed, in con- 

 tact with oxygen gas and the platinum sponge, in tubes bent into 

 the shape of retorts, which were immei'sed in a mercurial bath. 

 This bath was gradually heated to tlie required temperatures, 

 and by proper management of the source of heat, was prevented 

 from rising above that degree. 



1st. By subjecting 25 measures of carbonic oxide, 16 of 

 olefiant gas, and 57 of oxygen, in contact with the sponge, to a 

 heat which was not allowed to exceed 350° Fahrenheit till the 

 diminution of volume ceased, all the carbonic oxide was con- 

 verted into carbonic acid, and the olefiant gas remained in its 

 original volume. 



2d. By exposing in a similar manner 20 measures of carbonic 

 oxide, 21 of carburetted hydrogen, and 36 of oxygen, to a tern- 



