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ARTICLE XIII. 
On the Laws of the Conducting Powers of Wires of different 
Lengths and Diameters for Electricity ; by E. LEnz. 
(Read to the Academy of St. Petersburgh, the 28th of November, 1834.) 
From the Mémoires de l’ Académie Impériale des Sciences de St. Petersbourg: 
VI™. series, tom. i. 1835. 
Tuoucu Van Marum, Priestley, Children, Harris, and Davy* had 
previous to Galvani’s brilliant discovery endeavoured to determine the 
eonductibility of different metal wires by discharges of the Leyden bat- 
tery, yet the first more accurate experiments on this subject were made 
at a later period by means of the electromotor and the voltaic pile ; but, 
strange to say, these later and more accurate experiments have led to 
results at variance with each other. Whilst the experiments of Davy, 
Pouillet, Becquerel, Christie, Ohm, and Fechner prove the law that 
wires of the same metal conduct electricity inversely as their lengths, 
and directly as their sections—that is to say, as the squares of their 
diameters—Barlow and Cumming consider, according to their experi- 
ments, that the conductibility is inversely proportionate to the square 
of the lengths, and directly as the diameters of the wires (or as the 
square roots of their sections). Ritchie, whose observations on this sub- 
ject are the most recent (Phil. Trans. for 1833, p. 313), but who, un- 
fortunately, like most English authors, is totally unacquainted with the 
works of the German natural philosophers Ohm and Fechner, endea- 
vours to explain this contradiction by assuming that the conductibility 
of the wires varies according to the force of the current; for having 
connected two wires with two different batteries, he found by means of 
his galvanometer that the strength of the currents were not in the 
same proportion to each other. He explains this according to his own 
view of the conductibility of electricity in the following manner : 
“Let us suppose that there is no actual transfer of electricity along 
the wire, but that all the phenomena of deflection, &c. result from 2 
definite arrangement of the electric fluid essentially belonging to the 
wire itself. Let us further suppose that a section of wire contains one 
hundred particles of electricity, and that the battery is capable of ar- 
* ([M..Lenz is here in error; the experiments of Children, Davy, and Harris 
‘were all made subsequently to the discovery of Galvani.—Eprr.] 
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