100 Mr R. Adie’s Account of Electrical Experiments. 
a feeling of surprise from the close resemblance their action bore 
to the respiration of the lower classes of animals. In this arrange- 
ment of inorganic matter an electrical current is as much dependent 
on a supply of air for its maintenance, as the lives of plants or ani- 
mals are. Still, it should be borne in mind that, beyond the simple 
fact noticed, there is no further evidence of parallelism. 
Three pairs of the water battery are sufficient to decompose aci- 
dulated water with platina poles, and one pair serves to do so with 
copper poles. The battery excited by diluted sulphuric acid also 
requires three pairs to decompose water. Professor Grove has 
shewn that twenty-six pairs of his composition of water battery are 
necessary to perform the same decomposition, while three pairs 
acting only by their oxidation of zinc, are equally effective. Tak- 
ing these things into consideration, it appears to me, that for the 
great source of the galvanic current we must look to the composition 
of a metallic oxide, for which the presence of water is essential, 
although it is not always decomposed. 
On turning over in my mind the action of water on a galvanic 
couple, and comparing it with the gas battery, I was led to expect 
that if the most oxidizable metal of the former arrangement be 
removed, and its place supplied with one of the hydrogen tubes of 
Professor Grove’s battery, that the principle of the action would be 
unchanged. In lieu of the composition of the oxide of zinc, on the 
zine plate, there should be the formation of water on the platina 
plate ; the hydrogen being drawn from that contained in the tube, 
and the oxygen from the supply absorbed by the water from the 
atmosphere. A trial proved this view to be correct; the slip of 
platina in the hydrogen gas was the generating metal to a plate of 
either copper, silver, or platina, immersed in water holding oxygen 
in solution. I found the size of the conducting plate to possess 
much influence over the action; a large plate of silverfoil gave 
more electricity than a slip of platina corresponding in size to the 
generating plate. Pieces of copper of large dimensions are too apt 
to give opposite currents. 
When the above experiment shewed that the oxygen tube of the 
gas battery could be dispensed with, I wished to try its value as a 
sustaining arrangement. For this purpose it is necessary to cement 
inside the hydrogen tube a piece of zinc, unconnected with the pla- 
tina; then as the gas is consumed the acidulated water rises till it 
comes in contact with the zinc, when a fresh supply of hydrogen is 
obtained. A tube so prepared placed over a shallow vessel con- 
taining a piece of silverfoil for a conducting plate, gave an endur- 
ing action; and the electrical current derived from this single pair 
of composition of water plates, freely decomposed the argent cyanide 
of potassium. To avoid the sulphate of zinc being dissolved in the 
fluid in the battery cell, I have used an inverted U tube where the 
hydrogen is generated in a separate vessel; but the first method 
a 
