ow what happens. It is thrown
out, in part at least, under the epidermis, and there it remains to the
patient's dying day. This is a striking illustration of the difficulty
which the system finds in dealing with non-assimilable elements, and
justifies in some measure the vulgar prejudice against mineral poisons.

I trust the youngest student on these benches will not commit the
childish error of confounding a presumption against a particular class
of agents with a condemnation of them. Mercury, for instance, is alien
to the system, and eminently disturbing in its influence. Yet its
efficacy in certain forms of specific disease is acknowledged by all
but the most sceptical theorists. Even the esprit moqueur of Ricord,
the Voltaire of pelvic literature, submits to the time-honored
constitutional authority of this great panacea in the class of cases
to which he has devoted his brilliant intelligence. Still, there is
no telling what evils have arisen from the abuse of this mineral.
Dr. Armstrong long ago pointed out some of them, and they have become
matters of common notoriety. I am pleased, therefore, when I find so
able and experienced a practitioner as Dr. Williams of this city proving
that iritis is best treated without mercury, and Dr. Vanderpoel showing
the same thing to be true for pericarditis.

Whatever elements nature does not introduce into vegetables, the
natural food of all animal life,--directly of herbivorous, indirectly of
carnivorous animals,--are to be regarded with suspicion. Arsenic-eating
may seem to improve the condition of horses for a time,--and even of
human beings, if Tschudi's stories can be trusted,--but it soon appears
that its alien qualities are at war with the animal organization. So of
copper, antimony, and other non-alimentary simple substances; everyone
of them is an intruder in the living system, as much as a constable
would be, quartered in our household. This does not mean that they may
not, any of them, be called in for a special need, as we send for the
constable when we have good reason to think we have a thief under our
roof; but a man's body is his castle, as well as his house, and the
presumption is that we are to keep our alimentary doors bolted against
these perturbing agents.

Now the feeling is very apt to be just contrary to this. The habit has
been very general with well-taught practitioners, to have recourse to
the introduction of these alien elements into the system on