206 Mr. Haycraft on the Specific Heat of the Gases. 



Temperature of Calori. Temperature of Calori- 

 meter A, through meter B, through 

 which the Carbonic which Atmospheric 

 Acid passed. Air passed. 



At the beginning 1 ^ Fahr# 



of experiment, j 

 After 15 minutes, 



The comparative spe- 

 cific Heat of Carbonic 

 Acid inferred from 

 the comparative Rise 

 of the Temperature 

 of the Air beinglOOOO. 



At the beginning \ 

 of experiment, / 

 After 15 minutes, 



68/ n 



42 





At the beginning \ 42 



of experiment, J 

 After 40 minutes, 71, 



At the beginning) 45 



of experiment, J 

 After 35 minutes, 



68A 



At the beginning) 45i± 



of experiment, / 2 ° 



After 25 minutes, 63W\v 



No. 2. 



No. 3. 



No. 4. 



No. 5. 



42° Fahr. 

 68i§ 



66*$ 



42 



45 



4.R1 5 



'2TT 



9730 



9919 



10035 



10021 



10000 



In these experiments it will be perceived, that the two first 

 indicate that carbonic acid has a less capacity for caloric than 

 common air. The three last, however, which do not differ 

 materially from each other, will indicate an equal capacity, if 

 we take the average of their results. The cause of the two 

 first experiments indicating a lesser capacity, I suppose to 

 arise from the gas not being perfectly freed from watery va- 

 pours. In the experiments 1 made last year, I observed that 

 it was necessary to expose this gas to the drying influence of 

 muriate of lime, for 35 minutes at least before it indicated the 

 same specific heat as atmospheric air. This is not the case 

 with all the other gases : from hence I would infer, that it has 

 a greater affinity with watery vapour. 



The gas contained in the gasometer, as indicated by lime- 

 water, contained 99 per cent, of carbonic acid ; that taken from 

 the apparatus after the experiments were concluded, by the 

 same test, contained 90 per cent. The temperatures of the gases 

 while entering the calorimeters were equal, as indicated by the 

 thermometers. It is worthy of remark, however, that these 

 temperatures appeared several degrees lower than that of the 

 water contained in the heating apparatus through which they 



passed. 



