MR HAYCRAFT on the Specific Heat of the Gases. 209 



No. 2. 



The calorimeters were of a temperature of 52 -/^ at the be- 

 ginning of the experiment : after 55 minutes, the calorimeter A 

 had acquired a temperature of 92 ^ , and B that of 94 fa ; the sur- 

 rounding medium being 65. The average result of these experi- 

 ments, Nos. 1. and 2., indicates the specific heat of olefiant gas to 

 be 10559. Though the results of these two experiments do not 

 quite agree with those I formerly made, yet the difference is very 

 trifling, and may be supposed to arise from the greater freedom 

 of the gas I formerly made use of, from empyreumatic va- 

 pour. This will appear probable from the following experi- 



No. 3. 



The part of the apparatus B was filled with carburetted hy- 

 drogen, procured by the destructive distillation of mutton-suet. 

 The calorimeters were filled with water of the temperature of 

 50 g. At the end of 40 minutes, the calorimeter, through which 

 the olefiant gas passed, had acquired its extreme temperature of 

 95, the other that of 88 g ; the surrounding medium being 

 65 /o ; indicating the specific heat of olefiant gas to be 12777. 



That the gas procured from animal fat contains more em- 

 pyreumatic vapour, is evident from its sensible qualities, which 

 may account for its greater specific heat, compared with that pro- 

 cured from sea-coal. The gases, at the end of the experiment, 

 were exactly of the same temperature as when entering into 

 the calorimeters. 



No. 4. 



>"j.J<vi!.ry. . 1 ; ...i; '^, . 



The last experiment was repeated, except that the olefiant 

 gas was procured from alcohol and sulphuric acid. After 25 

 VOL. x. P. i. D d 



