Heinrich Friedrich Emil Lenz

“ From the great interest which the late discoveries of Faraday in the field of electro-magnetism must awaken in all the natural philosophers of Europe, it is to be expected that we shall soon receive many and various explanations of the momentary action of an electric current on an electrical conductor; and as it is allowed according to Ampère to reduce the action of a magnet entirely to that of circular electric currents, the same may be expected with respect to the action of the magnet upon such a conductor. ”

“ In order now to find the resistance which the electric current suffers in its passage through the different wires, I first reduce their lengths all to one diagonal, and indeed to that of the wire of the multiplier, on the principle that two wires of the same metal offer then the same resistance to conduction when their lengths are in the same proportion as their diagonals (See Ohm's Galvanic Chain) . ”

“ Here then the coincidence for this kind of experiments is very great, go that we may regard the position as entirely confirmed, namely that
"the electromotive power which the magnet produces in a spiral, with convolutions of equal magnitude and with a wire of equal thickness and like substance, is directly in the same proportion as the number of the convolutions." ”