any other substance. But simple as the substance appears, composition is
really very complicated. Professor Allman tells us that so difficult and
wonderful is its chemistry, that in fact really very little is known
about it. The best evidence we have, I believe, makes it tolerably
certain that protoplasm consists of a combination of ammonia, carbonic
acid, and water, and that every molecule of it is made up of 76 atoms,
of which 36 are carbon, 26 hydrogen, 4 nitrogen, and 10 oxygen.[1]

But no chemist has ever been able either to account theoretically for
such a composition, still less to produce it artificially. It is urged,
however, that it may be only due to our clumsy apparatus and still very
imperfect knowledge of chemistry, that we were unable artificially to
make up protoplasm.


[Footnote 1: Nicholson ("Zoology," p. 4) gives for Albumen, which is
nearly identical with protoplasm--Carbon, 144; Hydrogen, 110; Nitrogen,
18; Oxygen, 42; Sulphur, 2. These figures nearly equal those in the
text, being those figures multiplied each by 4 (approximately) and
without the trace of sulphur.]

And of course there is no answer to a supposition of this sort.
Nevertheless there is no sort of reason to believe that protoplasm will
ever be made; nor, if we could succeed in uniting the elements into a
form resembling protoplasmic jelly, is there the least reason to suppose
that such a composition would exhibit the irritability, or the powers of
nutrition and reproduction, which are essentially the characteristics of
_living_ protoplasm. It is not too much to say that, after the close of
the controversy about spontaneous generation, it is now a universally
admitted principle of science that life can only proceed from life--the