, hydrogen, and carbon, which, and
which alone, seem to be required by nature for laying withal the
foundations of vitality, inasmuch as no substance from which any one of
these ingredients is totally absent, ever exhibits any sign of life,
while, on the other hand, not only are these four ingredients sufficient
of themselves to form a substance capable of living, but they actually
do with very little (when any) foreign admixture, form all substances
whatsoever that are ever found vivified. All such substances, he informs
us, are but varieties of _protoplasm_, differing indeed from each other
in texture, colour, and general appearance, even as a diamond differs
from granite, yet all being equally protoplasm, just as a diamond and a
block of granite are equally stones, or as heart of oak and the outer
case of a nettle's sting are equally wood. The human ovum, he gives us
to understand, is in its earliest stage but a single particle of
protoplasm; the human foetus but an aggregation of such particles,
variously modified; the human body perfectly matured, but a larger
aggregation of such particles still further modified.

He proceeds to point out, as following from these premises, that a
solution of smelling salts, together with an infinitesimal quantity of
certain other salts, contains all the elements that enter into the
composition of protoplasm, and consequently of whatever substance the
very highest animal requires for sustenance. He does not, however,
leave us to suppose that any abundance of the fluid in question would
avail aught to save a hungry creature of any sort from starving, but
continues his exposition to the following effect. Not only is there no
animal, there is not even any vegetable organism, to which the elements
of food can serve as food, as long as they remain elementary. It is
indispensable that hydrogen and oxygen should combine to form water,
nitrogen and hydrogen to form ammonia, carbon and oxygen to form
carbonic acid; and even then, even at a table groaning under whole
hogsheads of these primitive compounds, there is no single animal that
would not find itself at a Barmecide feast. There are many plants
likewise, which in the midst of such uncongenial plenty would be equally
without a drop to drink; but there are also multitudes of others which,
without the aid of any more elaborated nutriment, would be able to grow
into a million, nay million million fold of their original bulk.
Provided there