MR. GROVE ON THE GAS VOLTAIC BATTERY. 
99 
battery, carefully protected by thick coatings of cement, passed under the edge of 
this vessel through the water, the exterior surface of which was covered with oil, 
more effectually 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 pro- 
duced ; hydrogen had been evolved from one of the platinums to the extent of 0*3 cubic 
inch in the cell containing 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 ni- 
trogen which covered the battery 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 mi- 
nutes, 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 hydrogen*. 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 oxy- 
hydrogen gas battery, but the action rapidly declines in the former, while it is con- 
stant in the latter. Even the ordinary action of the gas battery when charged with 
oxygen and hydrogen appears to me unanswerable as to the point I am now discuss- 
ing. When we see a battery of a number of cells at work, and the liquid gradually 
rising in the oxygen tubes, just in the proportion in which oxygen gas is eliminated 
in the voltameter, and when in a similar battery placed by its side, similarly charged, 
but not connected in closed circuit, not the slightest rise takes place in any tube, it 
seems impossible to adopt the conclusion that the oxygen has nothing to do with the 
current. Here we have no slight galvanoscopic effects, but chemical effects capable 
of quantitative admeasurement, capable of being continued to an extent only limited 
by the size of the apparatus, and equivalent to the chemical effects observable at the 
* 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. 
MDCCCXLIII. P 
