f some odorous substances
which possess the extraordinary power of diffusing their imponderable
emanations through a very wide space, however it may be abused in
argument, and rapidly as it evaporates on examination, it is not like
that just mentioned, wholly without meaning. The fact of the vast
diffusion of some odors, as that of musk or the rose, for instance, has
long been cited as the most remarkable illustration of the divisibility
of matter, and the nicety of the senses. And if this were compared with
the effects of a very minute dose of morphia on the whole system, or the
sudden and fatal impression of a single drop of prussic acid, or,
with what comes still nearer, the poisonous influence of an atmosphere
impregnated with invisible malaria, we should find in each of these
examples an evidence of the degree to which nature, in some few
instances, concentrates powerful qualities in minute or subtile forms of
matter. But if a man comes to me with a pestle and mortar in his hand,
and tells me that he will take a little speck of some substance which
nobody ever thought to have any smell at all, as, for instance, a grain
of chalk or of charcoal, and that he will, after an hour or two of
rubbing and scraping, develop in a portion of it an odor which, if the
whole grain were used, would be capable of pervading an apartment, a
house, a village, a province, an empire, nay, the entire atmosphere of
this broad planet upon which we tread; and that from each of fifty or
sixty substances he can in this way develop a distinct and hitherto
unknown odor: and if he tries to show that all this is rendered quite
reasonable by the analogy of musk and roses, I shall certainly be
justified in considering him incapable of reasoning, and beyond the
reach of my argument. What if, instead of this, he professes to develop
new and wonderful medicinal powers from the same speck of chalk or
charcoal, in such proportions as would impregnate every pond, lake,
river, sea, and ocean of our globe, and appeals to the same analogy in
favor of the probability of his assertion.

All this may be true, notwithstanding these considerations. But so
extraordinary would be the fact, that a single atom of substances which
a child might swallow without harm by the teaspoonful could, by an easy
mechanical process, be made to develop such inconceivable powers, that
nothing but the strictest agreement of the most cautious experimenters,
secured by every guaranty