428 Mr. Grove on the Gas Voltaic Battery. 



voltameter must require and absorb precisely as much heat as 

 is set free by the gases becoming liquid in each cell, it may be 

 a curious subject of future inquiry (an inquiry which that 

 beautiful instrument, the thermo-multiplier, will materially 

 aid) to ascertain whether the heat absorbed in the voltameter 

 be exacted from surrounding bodies, or whether it be supplied 

 by the action of the battery itself, i. e. as the chemical force 

 in the voltameter is conversely equivalent to that in each cell 

 of the battery, and the calorific force at the voltameter is also 

 the converse equivalent of that in each battery cell, whether 

 there is the same mutual dependence of the latter as of the 

 former forces. The action in the voltameter of ordinary bat- 

 teries would argue strongly against the proposition, that the 

 heat is exacted from surrounding bodies, as it is well known 

 that water when electrolysed has its temperature rather in- 

 creased than diminished; and I have found, when decompo- 

 sing water with the nitric acid battery at a rate of 150 cubic 

 inches a minute, a very considerable augmentation of tempe- 

 rature in the liquid subjected to decomposition, so much so, 

 that if the quantity was not considerable, it was heated to 

 ebullition. Much of this adventitious heat may have arisen 

 from the restriction of the circuit by the voltameter plates 

 and connecting wires, but if the gas battery be supposed to 

 supply exactly sufficient heat, or (to use a license of expres- 

 sion) to convert electricity into sufficient heat to satisfy the 

 demands of the expanding gases, — each battery cell being 

 able by the condensation of its respective gases to afford this 

 supply, — a rise of temperature ought to be perceptible in the 

 whole battery equal to the heat produced by the condensation 

 of gases in all the cells, minus that of one cell. I have not as 

 yet been able to detect any elevation of temperature due to the 

 action of the gas battery, not having in my possession any in- 

 strument capable of detecting such delicate thermoscopic 

 effects. I am, therefore, the more anxious to offer the point 

 for the consideration of those who may have such instruments 

 at their command ; and here for the present I leave the gas 

 battery and its theory. 



London Institution, March 12, 1843. 



Postscript, July 7th. 



The length of time which has elapsed between the commu- 

 nication and printing of this paper, as it has enabled me to 

 procure the apparatus fig. 8, will I trust be deemed a sufficient 

 reason for my adding a Postscript containing a few experi- 

 ments with this form of battery, some of which I cannot but 

 consider important. 



