352 Mr. Grove on the Gas Voltaic Battery. 



ful effects, as was expected by Dr. Schcenbein*; water was 

 decomposed between platinum electrodes by two cells. This 

 is the most powerful gas battery f, but not very satisfactory, 

 for the reasons above stated, experiment 13. 



Experiment 17. — Hydrogen and carbonic oxide were tried 

 in order to ascertain their voltaic relations. Hydrogen was 

 much more electro-positive than carbonic oxide, or rather 

 formed, with the oxygen of the atmospheric air in solution, a 

 combination which overpowered the opposite tendency of the 

 carbonic oxide and air. 



Experiment 18. — Chlorine and defiant gas gave a very 

 feeble effect upon iodide of potassium. After four hours the 

 liquid in the olefiant gas tubes had not risen more in the closed 

 circuit than in the detached pair; the chlorine was nearly all 

 absorbed in solution. 



Experiment 19. — Chlorine and carbonic oxide gave very 

 notable effects; ten cells decomposed water. From the ex- 

 treme solubility of the former gas, the equivalent relationship 

 could not be ascertained. 



It now occurred to me that as oxygen and hydrogen are 

 evolved from water by electrolysis, and conversely form water 

 bv electro-synthesis, so some other gases which are evolved 

 from certain electrolytes by voltaic action, might, when ar- 

 ranged as a gas battery with the electrolyte from which they 

 are evolved, give rise to a current, although they would not 

 do so when arranged in circuit with a different electrolyte. 

 To test this view I tried, 



Experiment 20, — Oxygen and deutoxide of nitrogen in al- 

 ternate tubes of the gas battery, with dilute nitric acid ; the 

 effects were however precisely similar to experiment 8, viz. a 

 very feeble action for a few minutes, then a cessation, and no 

 continuous chemical action. 



Experiment 21. — For the same reason oxygen and nitrogen, 

 with solution of sulphate of ammonia, were tried ; this arrange- 

 ment produced at first a slight effect upon the iodide, which 

 soon ceased, and after several clays there was no more rise of 

 liquid in any cell of the closed circuit than in the detached 



* See his letter, Phil. Mag., March 1843. 



+ Chlorine, in its voltaic relations, maybe considered as the converse of 

 zinc, both decomposing water, but the one liberating oxygen, the other hy- 

 drogen ; thus a tube of the gas battery charged with chlorine, and having 

 acidulated water as an electrolyte, and zinc as a positive clement, forms a 

 combination of which one pair will decompose water. I have tried to 

 render this combination practically useful, by charging the negative cell of 

 a nitric acid battery with peroxide of manganese and muriatic acid, but the 

 supply of chlorine thus obtained is insufficient for quantitative voltaic 

 effects, though the intensity is great. 



