280 EXPERIMENTAL INVESTIGATIONS. 



and voltameter. According to our received theory of caloric, 

 oxygen and hydrogen cannot assume the gaseous from the 

 liquid state without rendering sensible heat latent. Now, as 

 in the gas battery the gases evolved from the liquid in the 

 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 enquiry (an enquiry 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 sup- 

 plied 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, whe- 

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

 the former forces. The action in the voltameter of ordinary 

 batteries 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 decompos- 

 ing water with the nitric acid battery at a rate of 1 50 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 expression) 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 instrument 

 capable of detecting such delicate thermoscopic effects. I am, 

 therefore, the more anxious to offer the point for the consi- 

 deration of those who may have such instruments at their 



