Sf>g COMBUSTION OF CHARCOAL. 



State aft<* After the combustion the gas consisted of 



combustion* 



Carbonic acid mixed with 



sulphurous acid gas - r950*45 cent. cub. rr 57878 cub. in ? 



Oxigen gas. . . • • '595*06 =z 362*36 



Nitrogen 126-80 = 77*21 



Qxiearburetted hidrogen 15*89 zz 9'63 



* 1688-2 =1028-03 



From this combustion we cannot deduce any very precise 

 conclusions respecting the composition of carbonic acid gas; 

 Water pro- since, independent of the uncertainties arising from the 

 tuced. production of water, which amounted to 0-018 of a gr. 



[0*278 of a gr.] and of the oxicarbu retted. hidrogen, some, 

 sulphurous acid was produced, and absorbed by the potash 

 with the carbonic acicj. We may presume however, that 

 the charcoal contained but a very small quantity of sulphur 

 and hidrogen; for, if we were to consider the mixture of 

 carbonic acid and sulphurous acid gas as so much pure car- 

 bonic acid gas, the results of the combustion of tlje sul- 

 phuretted yr.d hidroguretted charcoal would approaph very 

 pear those furnished by the carbon of plumbago. 

 "Furnishes The results of this combustion however show, that the 



nearly as much charcoa 1 em ployed in the formation of hidroguretted sul- 

 common char- P nnr furnishes nearly as much hidrogen, as charcoal that 

 PpM ' has not been subjected to this process. Hence we may in- 



fer, that the hidrogen of the hidroguretted sulphur is not 

 furnished by the charcoal. Jt is probable, that sulphur con- 

 tains either water, or oxigen and hidrogen ; and that the 

 charcoal forms the hidroguretted sulphur by abstracting the 

 hidrogen. 



Central results, Recapitulation of the principal Observations, 



Plumbago. Cornish plumbago, burned in oxigen gas, yields nothing 



but carbonic acid gas and oxide of iron, without any mix- 

 ture of water, or of hidrogen gas. 



Its combustion shows, that J 00 parts of plumbago con- 

 tain 96 of carbon and 4 of iron; and that 100 parts by 

 weight of carbonic acid gas contain between 27*04 and 

 27*38 parts of carbon. We find the same results, whether 

 we calculate from the weight of the carbon burned, or the 



quantity 



