Mr. Grove on the Gas Voltaic Battery. 34-7 



exterior surface of which was covered with oil, more effectu- 

 ally to prevent the absorption of air. The terminal wires 

 were then united and left so. After two hours, when the 

 oxygen of the surrounding atmosphere had been exhausted by 

 the phosphorus, the effect became more feeble, but continued 

 throughout the evening. The next morning, however, the 

 inclosed battery produced not the slightest effect upon the 

 iodide, the liquid had risen in the hydrogen tubes about 0*2 

 cubic inch, but no other effect was perceptible. On the other 

 hand, in the battery which had been placed by its side, charged 

 in the same way, and similar in every respect but in the fact 

 of being exposed to the atmospheric air, a very decided effect 

 was produced ; hydrogen had been evolved from one of the 

 platinums to the extent of 0*3 cubic inch in the cell contain- 

 ing liquid, and a decided effect was produced on the iodide. 

 The two batteries were left in this state for three more days ; 

 the decomposition and the evolution of hydrogen continued in 

 the exposed battery, but none was perceptible in the inclosed 

 one, although the liquid had risen a little more, viz. 0*1 cubic 

 inch in the hydrogen tubes of the latter. After the four days 

 above mentioned, the jar of nitrogen which covered the bat- 

 tery was taken away, and the action of the battery was tested 

 by iodide of potassium. At first there was no action, but after 

 about fifteen minutes, a slight action was perceptible; this 

 gradually increased, and in two hours the action was equal to 

 that of the battery which had been from the first exposed to 

 the atmosphere. I cannot but regard this experiment as a 

 conclusive negation of that view which regards hydrogen and 

 water as the efficient agents in the gas battery. The opinion 

 appears to me to have arisen from the circumstance of our 

 working always in an atmosphere containing oxygen, and also 

 from the fact of this latter gas being more soluble than hy- 

 drogen*. If we lived in an atmosphere of hydrogen, and if 

 this gas were equally or more soluble than oxygen, I have little 

 doubt that the converse effects would be observed. A battery 

 charged with hydrogen in one set of tubes and acidulated 

 water in the alternate ones, at first gives an effect nearly equal 

 to an oxyhydrogen gas battery, but the action rapidly declines 

 in the former, while it is constant in the latter. Even the or- 

 dinary action of the gas battery when charged with oxygen 

 and hydrogen appears to me unanswerable as to the point I 

 am now discussing. When we see a battery of a number of 

 cells at work, and the liquid gradually rising in the oxygen 



* The tendency of oxygen to combine with platinum may also have its 

 influence. See M. De La Rive's various experiments on this subject, Bibl. 

 Univ. passim. 



