FAVRE AND SILBERMANN'S CALORIMETER 



is sufficient to cool the gas to the temperature of the bath. 

 Experimenters should solder the oxygen-jet to the stopper 

 so as to diminish the number of openings. It is also advan- 

 tageous to solder the coil to the cover. 



Certain fuels with very smoky flames require the addition of 

 oxygen very near their surfaces. Scheurer- 

 Kestner and Meunier-Dollfus employed the 

 following arrangement (Fig. 4), a being the 

 platinum capsule; cc r , the platinum tube, 

 which at the part c fits tight in the mouth 

 of the oxygen-jet; , $, ^, platinum suspen- 

 sion-rods; d, fuel. 



It is impossible to prevent the genera- 

 tion of more or less hydrocarbons and car- 

 bonic oxide. The weight of the hydrogen 

 and carbon is determined by causing the 

 gaseous products of combustion to pass 

 through an organic analysis tube, after re- 

 moving the water and carbonic acid. For 

 this purpose the exit-tube c (Fig. 3) is con- 

 nected by a caoutchouc tube with a Liebig apparatus, fol- 

 lowed by a U-tube of soda-lime. 



The gas-current being rather rapid, an absorption appa- 

 ratus must be used, large and powerful enough to completely 

 free the gas from the carbonic acid and water before it reaches 

 the red-hot copper oxide. This is done by passing the gases 

 through another U-tube smaller than the preceding, and whose 

 weight should vary only a few milligrams. The gases thus 

 freed pass to the tube of hot copper oxide, where the com- 

 bustible gases are burnt to water and carbonic acid, which are 

 collected and weighed as usual. 



Scheurer-Kestner and Meunier-Dollfus employed a plati- 

 num combustion-tube, and prefer soda-lime as absorbent for 

 the water after the conclusive experiments by Mulder.* 

 *Zeitschrift fur analytische Chemie, I. 4. 



