32 Voltaic Induction. 
If, however, we make these particles move downwards, in front of 
the magnet, one surface of each, the under one, will enter upon the 
line of induction at the very instant when, the opposite one is depart- 
Fig. 4. 
ing from it. At the under sides, therefore, it is supposed that the 
process commences and continues during this kind of motion. From 
the under side of a, the force Ne’ will repel a north polar force to- 
wards v’ and from that of a’, a similar one will revolve towards 2”, 
each being accompanied by equal forces of an opposite character, 
moving in a contrary direction in consequence of its attraction to- 
wards N. ‘The arches sz and s/n’ represent the respective direct- 
ions of these poles, which are supposed to revolve in curves around 
the particles, in consequence of their mutual attraction for the mat- 
ter. When the motion is discontinued, so will also the induction 
cease, and the polar forces, after revolving for a time in proportion to 
the impulse already received and the corpuscular attraction, pass 
into the particles and neutralize each other. But when the mo- 
tion is continued in the same direction, fresh magnetic forces act in 
quick succession upon the same surface, so as not only to augment 
the force and amplitude of the rotation produced by preceding ones, 
but to lead to their extension laterally, by the rapid generation of 
similar circles. ‘The result is the circulation of a voltaic current, 
passing through the particles at right angles to the magnetic rotation. 
the same particles a, a’, to move upwards before the magnet, at their 
upper surfaces will commence the induction, for the reason already 
assigned ; and this, leading toa rotation the reverse of the former, will 
be accompanied by'a current, likewise of an opposite nature. It is 
