278 Mr. H. F. Morley on Grove's Gas-Battery. 



action occurs at the junction of liquid, gas, and platinum ; 

 for the gas at that point remains of constant density, whatever 

 the resistance in circuit may be. 



VII. As an example of these views, an ordinary gas element 

 with platinized plates was joined through a resistance of about 

 10 ohms, including a galvanometer. After about 1 \ hour the 

 galvanometer was deflected 195 divisions ; and after 19 hours 

 the deflection was 189. The gas-element was now slanted at 

 an angle of 40°, the plates forming inclined planes ; the cur- 

 rent rose gradually, and after 2 J hours the deflection was 235, 

 after 23 \ hours it was 221. The element was now rotated 90°, 

 so that the plates were vertical, but their long diameter was 

 still inclined at 40° to the horizon ; the current rose instantly 

 to 265, and after 4| hours the deflection was 262. 



When the plates form inclined planes the line of junction 

 between liquid, gas, and platinum is not altered ; but the whole 

 surface of the liquid is increased, and the submerged plate is 

 brought nearer to it ; hence the current is increased. In the 

 last position an increased line of junction is added, and the cur- 

 rent is still greater. 



VIII. The current produced by the ordinary gas elements 

 which I used was always greater when the tubes contained 

 but little gas than when they were full of gas, the ratio being, 

 in three cases, If, 7, and 18. This is because the greater the 

 distance between the surface of the liquid in the tubes and the 

 air the purer will the solution of gas near that surface be. 

 Perhaps also the greater length of the plate may enable it to 

 catch gas that would otherwise escape: the internal resistance 

 between the most active parts, those near the surface, would 

 be rather increased than diminished. 



However, the cells are not at all regular in their action ; and 

 this may be due to irregularities in the deposition of the finely 

 divided platinum on the plates. These irregularities do not 

 affect VII., since the tendency of the cell on that occasion was 

 to become gradually weaker. 



IX. M. Gaugain found that the electromotive force of pla- 

 tinum-wire electrodes partly exposed to the gas was not altered 

 by submerging them. I have said why this does not appear 

 to me conclusive (5). But I inverted the experiment: ignited 

 wires were put several centimetres below the surface of the 

 gases ; the electromotive force was 102. They were then 

 raised so as to be only just submerged; the force was 134. 

 They were then thrust up into the gases, and the force was 136, 

 A key connecting the wires through a galvanometer was 

 pressed down until the needle had got to the end of its first 

 swing ; when the needle had come to rest the operation was 



