Mr. Haycraft on the Specific Heat of the Gases. 263 

 No. 2. 



Temperature of A, Temperature of B, 



containing Atnio- containing Hy- 



spheric Air. drogen Gas. 



At the beginning 1 , „ „ 



OT experiment, J 2 ° 25 Inferred Capacity. 



After 5 minutes, 55?% 55?° 10500 



After 10 minutes, 60 60?% 10424 



After 15 minutes, 64|° 64^ 9950 



After 20 minutes, 67/^ 67?% 10002 



After 25 minutes, 69^ 69?% 10000 



This last experiment was conducted as the former ones. 



The air appeared, after the experiments, to contain 88 per 

 cent, of hydrogen gas, as indicated by explosion with oxyo-en 

 gas *. 



In these two experiments it may be observed, that the watery 

 vapour which may be presumed to be in the hydrogen gas, 

 before it had been sufficiently exposed to the dryino- influence 

 of the muriate of lime, seemed to decrease in specific heat, ex- 

 actly contrary to what might be expected. In the first ex- 

 periment, at the expiration of the first five minutes, it had a 

 capacity of 9222, pretty nearly the same as indicated in the 

 experiments of Messrs. De la Roche and Berard ; but in pro- 

 portion as the experiment had advanced, and the hydrogen 

 had been exposed longer to the muriate of lime, its specific 

 heat approached to that of atmospheric air, till, at the end of 

 the experiment, they were quite equal. 



No. 2. was performed upon the same hydrogen, in its driest 

 state ; and throughout the whole experiment it indicated also 

 a capacity equal to the standard. In this experiment I know 

 of no source of fallacy, as the gases, while entering into the 

 calorimeters, were of exactly the same temperature, and care 

 was taken to ensure accuracy. 



Azote. 

 Of azote I shall merely state, that last year I performed 



* The apparatus which I found most convenient for exploding gases, is a 

 modification of Dr. Ure's syphon eudiometer. it consists of a hole bored 

 in the solid bottom of a mercurial trough, representing an inverted syphon ; 

 one end of which opens into the part containing mercury, and the other 

 through the edge of the trough to the open air. To the latter openin« 

 h cemented an open glass tube j and to the former a common graduated 

 eudiometer is made to fit accurately. When this apparatus is used, the 

 graduated tube is filled in the usual way, and applied to the opening com- 

 municating with the trough. Mercury "is poured into the other tube, to 

 the same height us that contained in the graduated one. The finger is 

 thru applied to the open tube, and the electric spark passed. After the ex- 

 plosion, more mercury is noured into the open tube, to the same height 

 that it had risen in the eudiometer, after which the degrees are read oft: 



similar 



