[DAWES] SPECIFIC HEAT OF A GAS AT CONSTANT PRESSURE 1 97 



(3) Again, in tliis method the measurement of the initial tem- 

 perature of the gas is exact, since all heat given up by it after it passes 

 the thermocouple is accounted for in the calorimeter readings. 



(4) It is necessary to heat the gas only to a comparatively low 

 temperature in order 'to have as favourable a dettermination as that of 

 Kegnault with the very high temperatures he used. Hence the disad- 

 vantages and limitations of using boiling oil as a heating bath are 

 avoided. The method may be readily applied to gases which are de- 

 composed at high temperatures. 



(5) The determination of the specific heat of a gas is reduced to 

 the measurement of rates, so that the initial and final adjustments of 

 conditions have not to be considered or allowed for. 



(6) The method may be readily adapted to the measurement of 

 the specific heat of liquids so that it gives promise of Becoming generally 

 useful. 



The writer would in conclusion express his sincere thanks to Prof. 

 J. C. McLennan for his kindly interest m this investigation, and his 

 helpful suggestions during its progress. 



Physical Laboratory, University of 'J'oronto. 



