278 Mr. Grove on the Gas Voltaic Battery. 



The nitric acid battery, an account of which I originally 

 published in 1839, having shown me the value of highly oxy- 

 genated acids and peroxides as voltaic excitants*, I deter- 

 mined, with a view of further extending the analogy of the 

 gaseous and metallic voltaic batteries, to try the nitric acid as 

 an electrolyte with the gas battery. Therefore, 



Experiment 5. — I charged a battery with hydrogen and 

 nitric acid in alternate cells, the nitric acid being only diluted 

 sufficiently to prevent injury to the wooden parts of the bat- 

 tery. With this arrangement I found that three cells were 

 capable of decomposing water, and thus, here also, the ana- 

 logy held good, the gaseous hydrogen deoxidating the nitric 

 acid in this arrangement, just as nascent hydrogen does in the 

 metallic battery. 



I now endeavoured to produce the converse effects, viz. to 

 form a battery in which oxygen should be the gaseous ele- 

 ment, and be absorbed by an electrolyte having an affinity for 

 it. To this end, 



Experiment 6. — I caused a battery often cells to be charged, 

 the one set of tubes with oxygen and the alternate tubes with 

 solution of protosulphate of iron. This battery decomposed 

 iodide of potassium, but was not able to decompose water; 

 the tubes which contained the solution of protosulphate re- 

 presented the hydrogen tubes of the ordinary gas battery. 

 The voltaic action caused by oxygen and protoxide of iron 

 was, however, but temporary i\ After a few hours it abated, 

 the iodide was no longer decomposed, and the liquid did not 

 rise perceptibly in the tubes containing oxygen ; the solution 

 when tested by ferrocyanide of potassium gave a blue precipi- 

 tate, indicating the presence of peroxide, but the greater por- 

 tion of this was probably formed at the expense of the atmo- 

 spheric air. 



In the last experiments and others, I had observed that a 

 more decided effect was obtained when free hydrogen alone 

 was present than when oxygen was alone. In my former 

 paper I attributed this to the atmospheric air in solution, and 

 for convenience of arrangement I have hypothetically assumed 

 this explanation in the commencement of this paper, but the 

 recent letter of Dr. Schcenbein induced me to look further 

 into this point. Therefore, 



* See Phil. Mag., May and October 1839, pp. 389 and 290. 



t In experiment 26 it will be seen that a continuous current is obtained 

 from oxygen and a liquid (ammonia); oxygen likewise gives a current with 

 solution of cyanogen, and probably with many organic compounds. 



[To be continued.] 



