64 CALORIFIC POWER OF FUELS. 



sugar (C^HJDJ, for which Berthelot and Vielle found 3961.7 

 calories. (Use 2 grams for a combustion.) 



Examples of Calculations. 



Mahler gives several types of calculations from his notes, 

 so as to show the different circumstances which may occur. 

 A. Colza Oil. Elementary analysis showed 



Carbon 77.182 per cent. 



Hydrogen 11.711 " " 



Oxygen and nitrogen 11.107 " 



100.000 " " 



Weight taken, I gram. Calorimeter contained 2200 grams 

 water. Equivalent in water of bomb, etc., 481 grams. 

 Pressure of oxygen, 25 atmospheres. 



The apparatus prepared as above was allowed to rest a 

 few minutes to gain equilibrium of temperature. Then com- 

 menced noting the temperatures. 



PRELIMINARY PERIOD. 



minute 10.23* 



1 " 10.23 



2 minutes 10.24 



Rate of variation, 



3 minutes 10.24 



4 " 10.25 



5 " 10.25 



10.25 10-23 

 a = - - = 0.004 . 



The electrodes are connected and the combustion begins. 



COMBUSTION PERIOD. 

 minutes 10.80 7 minutes.. 13.79 



12.90 



8 " .. 13.84 maximum.* 



* Prof. Jacobus recommends plotting the temperatures and using, not 

 the maximum, but the one at the instant the curve of cooling becomes a 

 straight line. The difference is slight, but important in some cases. 



