Chemical Instruments and Operations, 283 



13. ANALYSIS OF A GASEOUS MIXTURE, IN WHICH BIHYDROGU- 

 RET OF CAREON, CARBONIC OXIDE, AND EITHER HYDROGEN 

 OR NITROGEN, OR BOTH THE LATTER, ARE INTERMINGLED. 



When, as in the case under consideration in the preceding 

 article, there is no nitrogen present, the gas which remains 

 after the action of the hme-water, may be considered as ox- 

 ygen; but if nitrogen be present, the residual gas must be 

 analysed in order to ascertain the quantity of oxygen which 

 remains unconsumed. 



This is easily accomplished by propelling the residual gas 

 into the receptacle for carbonic acid, R, fig. 1, and substi- 

 tuting a self-regulating reservoir of hydrogen for the bell 

 glass. Then having filled the gage and pipes with the pure 

 hydrogen, by the manipulation already described in the case 

 of oxygen, (article 2,) the residual gas may be drawn into the 

 receiver, exploded, and the resulting deficit ascertained — ■ 

 to one third of which the oxygen is equivalent. 



Instead of resorting to the method just mentioned, the re- 

 sidual gas, after being included in the receptacle, may be 

 transferred to the pneumatic cistern, and analysed by the 

 aqueous sliding rod eudiometer.* 



If we subtract from the weight of the " residual gas''"' the 

 weight of the oxygen found in it, the remainder being both 

 incombustible and insusceptible of absorption by lime water, 

 should be considered as the weight of the nitrogen. This 

 would have to be deducted from that of the gaseous mix- 

 ture, the calculation being otherwise unaltered. 



If after having analysed a gaseous mixture, agreeably to 

 the directions given in the last article, it be found that the 

 quantity of hydrogen indicated exceed, in weight, one third 

 of the carbon allotted to it, the excess must be considered 

 as pure hydrogen : since, agreeably to the table of equiva- 

 lents, the weight of the carbon, in the bihydroguret, is to the 

 hydrogen, as 3 to l.t 



* See Memoir, vol. x. page 67 of this Journal. , 



f That is, puttincr H for the pure hydrogen, we should have 

 M + O — C _ 1 /3 C _ 3 X V 



9 3 \ 11 4 / 



