milarly how the characteristic properties of
protoplasm have sprung from properties in the water, ammonia, and
carbonic acid that have united to form protoplasm; but knowing all this,
we shall not be a hair's breadth nearer to the more recondite knowledge
up to which it is expected to lead. To extract the genesis of life from
any data that completest acquaintance with the stages and processes of
protoplasmic growth can furnish, is a truly hopeless problem. Given
the plan of a house, with samples of its brick and mortar, to find the
name and nationality of the householder, would be child's play in
comparison. Life, as we have seen, is not the offspring of protoplasm,
but something which has been superinduced upon, and may be separated
from, the protoplasm that serves as its material basis. It is,
therefore, distinct from the matter which it animates, and, being thus
immaterial, cannot possibly become better known by any analysis of
matter.

Of this emphatically vital question Professor Huxley, as has been
already intimated, takes a diametrically opposite view. He does not
merely, in sufficiently explicit terms, deny that there is any intrinsic
difference between matter and spirit, and affirm the two to be, in spite
of appearances, essentially identical. If this were all, I at any rate
should not be entitled to object, for I shall myself presently have
occasion to use very similar language, although attaching to it a widely
different meaning from that with which it is used by Professor Huxley.
But the latter goes on to avow his belief that the human body, like
every other living body, is a machine, all the operations of which will
sooner or later be explained on physical principles, insomuch that we
shall eventually arrive at a mechanical equivalent of consciousness,
even as we have already arrived at a mechanical equivalent of heat. He
considers that with the same propriety with which the amount of heat
which a pound weight produces by falling through the distance of a foot,
may be called its equivalent in one sense, may the amount of feeling
which the pound produces by falling through a foot of distance on a
gouty big toe, be called its equivalent in another sense, to wit, that
of consciousness. Yet he protests against these tenets being deemed
materialistic, which, he declares, they certainly neither are nor can
be, for that while he himself certainly holds them, he as certainly is
not himself a materialist. Professor