128 
MR. DANIELL ON VOLTAIC COMBINATIONS. 
myself, whether this unexpected difference, in the opposite direction to what I ex- 
pected, is dependent upon the construction of the cells or upon some accidental cir- 
cumstance which I have not been able to trace ; but the result may certainly be 
taken to prove that no advantage arises from the extension or approximation of the 
conducting metal which I have described. 
The increase of the number of the battery series requires for convenience a different 
arrangement from that which I described in my last communication ; and I now place 
the cells in two parallel lines of ten each, upon a long table, the siphon-tubes arranged 
opposite to each other, and hanging over a small gutter placed between the rows, to 
carry off the refuse solution when it is necessary to change the acid ; and as the uni- 
formity of action may be completely maintained by the occasional addition of a small 
quantity of fresh liquid, I have been able to dispense with the cumbrous addition of 
the dripping funnels. This arrangement admits with facility of any combination of 
the plates which may be desired. 
I proceeded now to connect the cells together in pairs ; the zinc rod of each ribbed 
cell being in communication with that of a plain cell, and the copper with the copper. 
The ten pairs were then connected in a series of ten : the product of this combination 
was 1 “ cubic inches per five minutes, or exactly double that of the single-ribbed cells. 
Considered in a theoretical point of view, these experiments seem to me to lead to 
the conclusion that the most perfect voltaic combination would consist of a solid 
sphere of a generating metal, surrounded by a hollow sphere of a conducting metal, 
with a stratum of intervening electrolyte perpetually renewed, and the metals com- 
municating by a wire defended from the electrolyte by a glass tube covering that por- 
tion which it would be necessary should pass through it. In such a hypothetical 
arrangement, the resistance of the electrolyte would increase directly as the distances 
of the two spheres, or as the thickness of the stratum ; while, supposing this resist- 
ance overcome, the quantity of force set in circulation would increase as the square 
of that distance from the centre, or as the surface of the exterior sphere. The num- 
ber of a series required to give the necessary impulse would consequently only in- 
crease as the simple distance, while the advantage would increase as the square. 
The rod of zinc within the cylinder of copper is probably the nearest practical 
approximation which can be made to such an arrangement ; but the soundness of this 
deduction might doubtless be tested by varying the diameters of the cylinders. 
The battery which I have now described, consisting of twenty cells, will, I think, 
be found amply sufficient for all the purposes of demonstration and investigation. It 
is competent to keep eight inches of platinum wire -rTrth inch permanently red hot 
in the open air; and the amount of work which it is able to perform renders it even 
an economical source of the purest oxygen for laboratory purposes. 
To facilitate this application, I have fitted up a cell by inclosing a platinum plate, 
instead of the zinc rod, within the membranous tube, which is closed at the upper end 
by a glass tube bent in a convenient form to deliver the disengaged gas under a 
