30 



Voltaic Induction. 



dynamic cylinder, or in right lines diverging from the magnetic axis 

 N S. Let S denote a piece of steel placed within their influence. 

 Now it is evident that were they to pass uninterruptedly, i. e. by the 



Fig. 3. 



x 



X X 



I 



X 



X 



X 



■ 



lines y x, they would act with equal intensity upon the opposite sides 

 of the line of particles 0, a, a, a, &c, through which they pass, and 

 thus destroy each others influence. But if we suppose that, upon 

 entering the surface c, d, of the steel, they suffer a deflection from 

 the magnetic axis N S, their action would be thrown into the dotted 

 lines, Vj r, and this would bring them in contact with only one side of 

 every particle. Induction, therefore would commence upon the un- 

 der sides of all the particles, a, above the magnetic axis N S, and 

 upon the upper surfaces of those below it ; the north poles of all the 

 superficial particles, here only represented, would be repelled and 

 revolve from N, while corresponding south polar forces would, 

 in consequence of attraction, revolve around the particles, towards 

 N ; and as the latter are those that issue from the surface c d, they 

 would give to the steel, S a south polarity, the opposite of that pos- 

 sessed by N. The duration of this rotation, after the magnet is with- 

 drawn, most probably depends upon the molecular condition of the 

 steel, since we find that caloric, which expands the particles, enables 

 the forces to return to a state of neutrality.* 



• This mode of explaining magnetic induction, is offered as mere conjecture. It 

 does not, indeed, account for the absence of a voltaic current; but is not opposed to 

 the supposition that the circulation is confined to the particles, individually. 



