COMBUSTION OP CHARCOAL AND OF HIDROGEN. j^| 



forming carbonate of Darytes.' The gasses were always left 

 to stand on potash previous- to the detonation:* a precaution 

 particularly necessary for the bxigen'gas I employed, and* 

 which 1 obtah/ed from bximuriate of potash'. This gas is 

 never free from 'a few thousandth parts of its bulk of car- 

 bonic acid. 



A thousand parts of hidrogen gas obtained from the so- R esu its, 

 lufidn of zinc purified by sublimation, when detonated 

 with 1000 parts of 'oxigen gas, afforded 3 parts of carbonfc 

 acid efas; • • ■• • 



rfidrogen gas obtained from the zinc of the shops, which- 

 had^iot been sublimed, produced the same quantity of acid 

 as the preceding. • *•• ' -t 



A thousand parts of hidrogen gas" from' the solution" of 

 iron produced '4*5 of acid gas in a similar process. • 



•The hidrogen gas from solution 'of tin in muriatic* acid 

 afforded 9 pafts of carbonic acid. * 



That from the decomposition of water by Volta's pile, 3 

 parts. 



That from the decomposition of 'ammonia; 10 parts, * 



To render such smailr quantities- of carbonic acid j,as 

 sensible, I effected the, absorption over mercury in a thbe 

 of such length, that the* column of gas I examined was 7 

 dec. [27*5 inches] high, and 13 niil. [0*5 of an inch] in 

 diameter. The puocess was not finished in less than 24 

 hours. . . 



It maybe supposed, that the diminution of the gas by ^ n it ro us -ra- 

 the potash was owing to the absorption of nitrous vapour, pour affected 

 which might be formed in these combustions where a small l ese * 

 quantity of nitrogen is always present : but I constantly made 

 the detonation over an ex-tensive surface of water, and left 

 the residual gas ill contact with this fluid for an hour, or a 

 sufficient time to prevent any suspicion of the presence of 

 this vapour. 



I have said, that, when barytes water was employed in- Barytes -water 

 stead of potash, the earth was precipitated in the state of ,et ,al1 a carw - 

 carbonate. Not to be deceived in a result so small, T in- ° Bate * 

 traduced two ounces of an aqueous solution of barytes with 

 excess of water into a globe of thick glass, the capacity of 

 which was 754 cub, ceut. [46 cub. inches.] 



Thia 



