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XXXIX. On Grove's Gas-Battery. 

 By Henry Forster Morley, M.A., B.Sc* 



IT appears to me that the question as to the mode of action 

 of the well-known gas-battery has not yet been definitely 

 settled. 



1. The discoverer says, " The chemical or catalytic action 

 can only be supposed to take place, with ordinary platina-foil, 

 at the line or water-mark where the liquid, gas, and platina 

 meet " f. Nevertheless he showed that water containing oxygen 

 in one tube and hydrogen gas in the other tube gave a conti- 

 nuous currentj . As regards exp. 29 in the last-quoted excel- 

 lent paper (viz. the experiment in which, hydrogen being in 

 one tube and nitrogen in the other and no oxygen being dis- 

 solved in the liquid, hydrogen was found to appear in the 

 nitrogen tube), as Mr. Grove does not say that there is a cur- 

 rent, and as the presence of a current would contradict the 

 conservation of energy, I am inclined to think that the effect 

 is due to diffusion, and that it would occur whether the plati- 

 nums were joined or not. 



2. Mr. Justice Grove says that the phenomenon does not take 

 place when the nitrogen is absent and its place filled by the 

 liquid ; and this is just what we should expect if the effect is 

 due to diffusion. Mr. Grove thought it just possible that the 

 hydrogen decomposed the water in its tube, combining with 

 the oxygen, and that an equal amount of hydrogen was libe- 

 rated in the other tube. Since the total amount of water is 

 not changed, it is clear that such a decomposition could not be 

 accompanied by a current. 



3. Nevertheless Dr. Schonbein said that pure water con- 

 taining no oxygen in one tube and an aqueous solution of hy- 

 drogen in the other gave a continuous current§. M. Gaugain 

 makes the same assertion, but adds that he deprived his water 

 of air by boiling || . To boil water and then let it stand in the 

 air is evidently not enough to deprive it of oxygen ; hence 

 these anomalous results may be due to the water not having 

 been absolutely free from oxygen. Such a current, as before 

 stated, would contradict conservation of energy : indeed it has 

 been shown by Mr. Grove that water absolutely free from 

 oxygen in one tube and hydrogen gas in the other tube pro- 

 duces no current^". 



* Communicated by the Physical Society. 



t Phil. Mag. December 1842. See also Phil. Trans. 1843, p. 107. 



X Phil. Trans. 1843, exp. 28 &c. 



§ Phil. Mag. March 1843. 



|| Comptes Rendus, February 25, 1867 ; Phil. Mag. June 1867. 



<|] Phil. Trans. 1843, exp. 7 and elsewhere. 



