l66 COMBUSTION OF CHARCOAt AND OF HIDROGEN. 



Apparatus for the combustion of charcoal. 



Apparatus for The combustion was effected in the sun, by means of a 



thecorubus- , r .._... . 



tion of char- Iens °-325 met. [1-2*8 inch.] in diameter, in a tubulated re- 



c P a *» ceiver with a steel cock, which contained about 2600 cent, 



cub. [158 cub. in,]. The charcoal was fastened by a wire 

 of platina to a plate of the same metal, which was suspended 

 in the middle of the receiver by a chain of platina fastened 

 to the top of the vessel. Near its point of suspension, and 

 in the tubulure, was fastened to the chain a small cylinder 

 filled with muriate of luue, which had been weighed in a 

 closed vessel previous to the experiment. 



The receiver was suspended between two vertical pillars 

 by a horizontal bar fixed to the tubulure, and crossing the 

 pillars in the direction of their diameter. This bar could 

 be moved up and down between the pillars, and be fixed 

 by screws; so as to keep the receiver immersed more or less 

 in a mercurial trough, which was deep enough to fill the 

 receiver with mercury, when plunged into it perpendicu-r 

 larly with the cock open. The mercury was previously 

 dried, and the tu ulure alone was left full of common air, 

 that the mercury might not mix with the rouiiate of lime, 

 Oxigen gas from the oxi muriate of potash was introduced 

 into the receiver, by fitting to the tubulure a bladder filled 

 with this gas, and furnished with a cock, and raising the 

 receiver to a prpper height; after which the cocks were 

 closed. 



To extract the gas from the receiver, I screwed on the 

 tubulure a small glass globe filled with mercury. On open- 

 ing the cocks, the mercury in the globe fell into the re- 

 ceiver, and was replaced by the gas in the latter. The'pipe 

 of the cock of the tubulure had a tube leading into the 

 receiver to convey the mercury free of the muriate of lime. 

 Before I commenced the process of combustion, I always 

 extracted in this way a part of the oxigen gas that had been 

 introduced iritp the receiver, and subjected it to analysis. 

 Eudiometrical To ascertain the proportion of oxigen gas, I employed 

 processes. For ^ hidrosulphuret of potash, concentrated, and impregnated 

 with nitrogen gas; and I always compared this process with 



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