5 03 
and magnetic rotations. 
point moved on to 12 0 from its position at the beginning of 
the experiment. On stopping the motion, the needle ad- 
vanced 11 5 0 , and then rested. 
These experiments appear to me to admit of explanation, 
on precisely the same principles which I had previously ap- 
plied to those relating to magnetism. It seems that electricity 
excited by induction is not instantly destroyed by removing 
the inducing body; nor is it instantly excited, to the full 
extent which the circumstances admit, on presentig an excited 
to an unexcited body. Admitting this principle, the whole 
of the reasoning which was given at the commencement of 
this paper, relative to rotations from magnetic causes, applies 
equally to those which arise from electricity. 
The velocity with which electricity travels, has been urged 
as an objection to this explanation of the phenomena ; and 
the immense rapidity with which the metals conduct that 
fluid, renders it difficult to admit that the motions employed 
in these experiments are at all comparable with that of elec- 
tricity. There are two circumstances that may be stated as 
some explanation of this difficulty: the first is, that although 
the forces thus set in action are exceedingly weak, yet, from the 
nature of the apparatus, they act constantly for a considerable 
time, and in the same direction ; thus gaining, by the duration of 
their total action, a power far superior to the almost infinitely 
small one which arises from the transient action of each 
part ; the second is, that although the velocity with which 
electricity of considerable intensity moves through good 
conductors is excessively great, I am not aware of any ex- 
periments which prove that the small inequalities which are 
produced in a very weakly electrified body by induction from 
