458 Analyses of Books. [JuNE, 
our senses ; but if we place such a body near a substance in a 
state of excitement, the attraction of the preponderant force in 
this last for the opposite force in the body and the repulsion 
which it exercises on the same force in the body will disturb the 
equilibrium, and will occasion an excess of positive force in one 
part of the body, and an excess of negative force in another part, 
leaving a zone between them in which the two forces are in 
equilibrium. If the excited body be removed, the equilibrium 
will be restored by the mutual action of the forces on each other. 
This fact that bodies become electric when brought into the 
neighbourhood of an excited body, which holds universally, 
demonstrates that every body contains the two electric forces, 
though in a latent state, in consequence of their mutual 
attractions. . 
When the body whose electrical forces are thus disturbed is 
brought still nearer the excited substances, the opposition of its 
forces augments considerably the portion nearest, the excited 
body acquires more and more of the opposite electricity ; while 
the portion further distant from it acquires more and more of the 
same kind of electricity. When the distance is diminished to a 
certain point, which varies according to circumstances, the 
electricity of the second body, which is attracted by that of the 
first, unites with it, and disappears at the same time ; so that 
nothing remains but a portion of the electricity of the first body, 
and the electricity of the same kind accumulated in the most 
distant part ofthe second body. Only the same kind of electri- 
city now remains in these two bodies. This has made electri- 
cians regard the process as the communication of electricity 
from the first body to the second. 
It is obvious from these facts and many others stated by Prof. 
CErsted that when electricity is accumulated in a body, it occa- 
sions the accumulation of the opposite kind of electricity in the 
zone next it by attraction, and the accumulation of the same 
kind of electricity in the zone next in succession by repulsion. 
It attracts the opposite electricity, renders it latent, while it is 
itself rendered latent at the same time. The second zone occa- 
sions a new zone of opposite electricity, which render each 
other latent in the same manner. Thus electricity is always 
propagated in an undulating manner. These changes succeed 
each other so rapidly in good conductors that we cannot observe 
them; but in bad conductors we can distinguish by means of 
the electrometer alternate zones of positive and negative electri- 
city. Thus the transmission of electricity is merely a change in 
the equilibrium of the natural forces of bodies. 
The transmission of electricity depends upon its intensity and 
upon its quantity. The intensity is measured by the greatness 
of the attractions indicated by the electrometer. The quantity 
may be measured by the surface charged with electricity up to a 
certain electrometrical degree. Other things being the same, 
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