120 Mr. Grove on the Effect of 



be observed, that the effects with the above liquids are by no 

 means in direct relation with their respective specific heats ; 

 but in order to bring the results of the experiments with 

 liquids into comparison with those with gases, I now asso- 

 ciated a gas with a liquid, viz. hydrogen with water. All 

 things being disposed as before, the tube A was filled with 

 hydrogen gas, the tube B with water, both being immersed in 

 3 oz. of water. The thermometer rose in five minutes — 

 In hydrogen. In water. 



From 60° to 75°-S. From 60° to 72°. 



This experiment of itself conclusively negatives the possi- 

 bility of specific heat alone accounting for the phaenomenon 

 under consideration ; and though, doubtless, specific heat 

 must have some influence on the cooling effects of different 

 gases and liquids, yet in the former it is apparently of very 

 trifling import in comparison with the real physical cause of 

 the differences, whatever that may be. 



Supposing, as is stated by Faraday*, that gases possess 

 feeble conducting powers for voltaic electricity, and supposing 

 hydrogen, from its close analogy in chemical character to 

 the metals, to possess a greater conducting power than the 

 other gases, this would account for its peculiar effect on the 

 ignited wire, as a certain portion of the current, instead of 

 forcing its way through the wire, would be carried off by the 

 surrounding gas. In order to ascertain this I arranged the 

 following experiments. 



1st. Into the closed end of a bent tube, fig. 2, a loop of 

 platinum wire, AB, and two separate platinum wires CD, 

 were hermetically sealed, the extremities of the latter being 

 approximated as closely 



as possible, and the in- F'g- ^' 



terval between them be- 

 ing close to and imme- 

 diately over the apex of 

 the loop. The tube was 

 filled with hydrogen, 

 and the wire AB con- 

 nected with a voltaic 

 battery of sufficient 

 power to raise it to as 

 high a degree of igni- £- 

 tion as it would bear 

 without fusion ; C and -^ 

 D were now connected 



* Experimental Researches, §§ 272, 441 and 444 



