Mr. Grove on the Gas Voltaic Battery. 351 



examination. It is well known that chlorine of itself will 

 slightly decompose water, forming hydrochloric acid, and 

 evolving oxygen, and there is little doubt that the voltaic ac- 

 tion here observed was due to this. There was no appear- 

 ance of the platinum having been attacked in several experi- 

 ments which I made with chlorine. So slight a chemical 

 action will, however, give rise to voltaic effects, that the ab- 

 sence of any apparent corrosion is not conclusive. It is stated 

 by chemists that gaseous chlorine will not attack platinum, 

 but that it is only when nascent it combines with this metal; 

 non constat however, that in the gas battery the chlorine at 

 the initiatory instant of its electro-synthesis may not be in a 

 state analogous, as to its chemical energies, to that converse 

 state called nascent, and therefore we cannot venture to nega- 

 tive the possibility of the platinum being slightly attacked. 

 This circumstance, added to its extreme solubility and power 

 of decomposing water, makes chlorine rather an unsatisfactory 

 element for the class of actions developed by the gas battery. 



Solutions of bromine, chlorine and iodine, have been before 

 experimented on (I believe by Dr. Schcenbein and M. Bec- 

 querel) as to their voltaic relations, but in examining the vol- 

 taic relations of bodies in a gaseous state, or to express myself 

 with more caution, in a state passing from gaseous to liquid, 

 I tried, 



Experiment 15, — One set of tubes charged with gaseous 

 chlorine, and the alternate tubes with solutions of bromine 

 and iodine. The chlorine was negative to both, i. e. was to 

 these as oxygen to hydrogen. 



I now tried hydrogen with several gases, but as it was next 

 to impossible (I found it quite impossible), in experiments on 

 a large scale, perfectly to exclude atmospheric air from the so- 

 lution*, voltaic action was produced in every case; and as 

 with one exception (chlorine) oxygen was the most powerful 

 electro-negative gas, the action of the atmospheric air entirely 

 masked any effect which might have been produced by the 

 other gasesf. I shall, therefore, not go through these expe- 

 riments in detail, but mention one or two only which appear 

 interesting, for the reasons which I shall state. 



Experiment 16. — Chlorine and hydrogen gave very power- 



* Gases will creep by a species of endosmose through water. Some time 

 ago I kept inverted over water for two months, a vessel divided by a dia- 



Khragm of porous ware, on one side of which was oxygen gas, on the other 

 ydrogen ; the diaphragm was constantly wet from capillary attraction ; at 

 the end of that period the water had risen considerably, and the gases on 

 each side detonated. 

 ■| See Postscript. 



