In every part of the animal economy, polar derangements in the
electro-vital principle are liable to occur. These derangements are
always the real foundation of disease. They may be occasioned by a
thousand agencies, which act as the _procuring_ cause of disease; but
the _proximate_ and _sustaining_ cause is polar disturbance--derangement
of the electro-vital poles. Parts which, in health, are relatively
positive, may become negative, and that which should be negative may
become positive. Or again, a part, naturally positive to its
counterpart, may become _excessively_ so, and that which should be
relatively negative may become negative to a _morbid degree_.
To correct these polar disturbances and restore the normal polarization,
is to _cure the complaint_. This is, under the treatment of most
physicians, often accomplished by the use of medicines, and by
mechanical or surgical agency. We accomplish it by the proper
application of the _poles_ of our electrical apparatus. In cases where
there is _virus_ to be destroyed, or _abnormal growths_ to be removed,
we also secure the _chemical_ action appropriate to these ends by the
proper _selection of our current_. It often happens that _mechanical_ or
_surgical action_ is demanded. In many _such_ cases, we do not profess
to secure normal polarization and consequent cure by means of
electricity alone. Yet, in a large proportion of the cases where
mechanical or surgical agency is usually thought to be indispensable,
we are able to cure by electric action only, since by it we can exert
very considerable mechanical force at will; and can also, in many
instances, attain much more happily, by means of electricity, the very
ends or the _best_ ends which would be aimed at by skillful surgical
operations.