m4 
50 Mr.J.S. Stuart Glennie on the 
repulsion of the body. Molecular and bodily motion, or resist- 
ance thereto, are inversely as each other. Hence, if a force has 
more effect in producing molecular displacement in one body | 
than in another, the difference will be seen in a tendency to repel 
this second body, the reaction of which will evidently urge the 
first towards the centre of force. | 
24. A corollary of this theorem is, that electrified bodies 
of which either the molecular tension or the inductive lateral 
disturbance is in the same direction approach; or, as it may be 
otherwise more concretely expressed, opposite poles, and similar 
currents, attract. For it is evident that, when the directions of 
the molecular displacement of two bodies are in the same line, a 
point of increased, is opposite a point of diminished, molecular 
pressure. Hence, transmission of similar molecular displace- 
ment from the one is in this position less, in the opposite, more, 
resisted by the other than by the medium. And hence, as 
above, attraction in the former, and repulsion in the latter case. 
Further, it is evident that, according as two parallel currents 
or lines of tension are in the same, or in opposite directions, will 
their lateral disturbance of equilibrium be im the same, or in 
opposite directions inwards; and hence, that the reverse lateral 
motions, or at least tendencies to motion, cf the bodies, accord- 
ing as their currents are in the same, or opposite directions, are 
explicable in the same way as, above, the motions of bodies with 
the same, or opposite directions of molecular tension, that is, 
with opposite, or the same poles opposed. 
25. The special facts which seem to justify the advancing of 
the above theorem and its corollary as a true generalization and 
mechanical explanation of electric and magnetic motions, may be 
summed up under the following experimental conclusions :— 
Paramagnetism and diamagnetism are not absolute, but relative 
conditions of bodies. Paramagnets tend to pass from weaker to 
stronger, and diamagnets from stronger to weaker, places of 
action. ‘Two of either class repel, and one of each attract. These 
motions would be explicable as due to differences of conduction ; 
but magnetic, is quite different from electric, conduction. As to 
these facts, if their mechanical meaning is not from the foregoing 
sufficiently clear, remark that, the tension of a magnetized body 
being spiral, while that of a body with an “open current” is 
longitudinal, the directions of the lateral imductive actions of a 
magnet and an ordinarily electrified body will be different, and 
hence the molecular conditions which permit of electric, will be 
different from those which favour magnetic, conduction. And if 
differences of conduction, that is, of molecular displacement, are 
thus admitted in the explanation of paramagnetic and diamagnetic 
phenomena, it is evident, from what has been already said of the 
