312 LENZ ON THE VARIOUS CONDUCTING POWERS 
ranging one fourth of these, or twenty-five particles, then there will only 
remain seventy-five to be arranged by any increase of power. Let us 
now suppose we have another wire of the same length, whose section 
contains only twenty-five atoms; it is obvious that this battery will be 
able to arrange more than one fourth of this number, so that the ratio 
of the conducting powers cannot be as one to four, but will be found 
by actual experiment a very different ratio. If we increase the size of 
the battery, suppose the size of the plates to be doubled, then it is ob- 
vious we shall not double the deflecting power. For out of one hun- 
dred particles there are only seventy-five remaining, a part of which 
only can be arranged by the increased part of the battery. Hence the 
deflecting force increases very slowly with the increased size or energy 
of the battery.” 
That this view of Ritchie’s is wrong may easily be proved by ex- 
periments, of which the numerical determinations of Fechner afford 
numerous examples. There are, in fact, some arrangements, particu- 
larly in closed galvanic series, which show such a relation between the 
pile and the connecting wires, that the increase of the plates does not 
perceptibly increase the strength of the current in the wire. This 
would, according to Ritchie’s opinion, prove the whole of the fluid to 
be already entirely disposed of, and that it would be impossible to pass 
any more fluid through the same wire. But this is by no means the 
case; for if, instead of doubling the number of plates, their size be 
doubled, the force will be almost exactly double. This proves, there- 
fore, that the whole of the fluid has not yet been disposed of, and that 
another arrangement of the voltaic pile only was required to produce 
the arrangement of a double number of particles of the fluid. Besides, 
Ritchie’s theory does not explain the difference of effect produced by 
a voltaic pile of many plates, and by one of fewer plates but of larger 
size. 
Ohm however several years ago furnished us with a theory of the gal- 
vanic battery which supplies this deficiency ; but being only published 
in German, it is unknown both in France and in England. This theory 
explains perfectly the difference between Barlow’s results and those of 
other natural philosophers who have occupied themselves with this 
subject, as well as the doubts of Ritchie. The latter says, in his paper 
above quoted, that “ The conducting power of a wire must be a func- 
tion of all the quantities concerned in the experiment. These quantities 
are obviously the diameter of the wire, its length, the size of the battery, 
and the strength of the acid.” Had he, instead of the term “ conducting 
power” used that of strength of the current, he would have been nearer 
the mark, and given a proper explanation of those apparent anomalies. 
Before quoting the simple formula of Ohm we must observe, that 
this philosopher always uses the term conducting resistance instead of ; 
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