Lectures and Essays | Page 5

one place to
another; and to enable it to do this, it has those strong contractile
bundles of muscles attached to the bones of its limbs, which are put in
motion by means of a sort of telegraphic apparatus formed by the brain
and the great spinal cord running through the spine or backbone; and to
this spinal cord are attached a number of fibres termed nerves, which
proceed to all parts of the structure. By means of these the eyes, nose,
tongue, and skin--all the organs of perception--transmit impressions or
sensations to the brain, which acts as a sort of great central
telegraph-office, receiving impressions and sending messages to all
parts of the body, and putting in motion the muscles necessary to
accomplish any movement that may be desired. So that you have here
an extremely complex and beautifully-proportioned machine, with all
its parts working harmoniously together towards one common
object--the preservation of the life of the animal.
Now, note this: the Horse makes up its waste by feeding, and its food is
grass or oats, or perhaps other vegetable products; therefore, in the long
run, the source of all this complex machinery lies in the vegetable
kingdom. But where does the grass, or the oat, or any other plant,
obtain this nourishing food-producing material? At first it is a little
seed, which soon begins to draw into itself from the earth and the
surrounding air matters which in themselves contain no vital properties
whatever; it absorbs into its own substance water, an inorganic body; it
draws into its substance carbonic acid, an inorganic matter; and
ammonia, another inorganic matter, found in the air; and then, by some
wonderful chemical process, the details of which chemists do not yet
understand, though they are near foreshadowing them, it combines
them into one substance, which is known to us as 'Protein,' a complex
compound of carbon, hydrogen, oxygen, and nitrogen, which alone
possesses the property of manifesting vitality and of permanently
supporting animal life. So that, you see, the waste products of the
animal economy, the effete materials which are continually being

thrown off by all living beings, in the form of organic matters, are
constantly replaced by supplies of the necessary repairing and
rebuilding materials drawn from the plants, which in their turn
manufacture them, so to speak, by a mysterious combination of those
same inorganic materials.
Let us trace out the history of the Horse in another direction. After a
certain time, as the result of sickness or disease, the effect of accident,
or the consequence of old age, sooner or later, the animal dies. The
multitudinous operations of this beautiful mechanism flag in their
performance, the Horse loses its vigour, and after passing through the
curious series of changes comprised in its formation and preservation,
it finally decays, and ends its life by going back into that inorganic
world from which all but an inappreciable fraction of its substance was
derived. Its bones become mere carbonate and phosphate of lime; the
matter of its flesh, and of its other parts, becomes, in the long run,
converted into carbonic acid, into water, and into ammonia. You will
now, perhaps, understand the curious relation of the animal with the
plant, of the organic with the inorganic world, which is shown in this
diagram (Figure 3).
(FIGURE 3. Diagram showing material relationship of the Vegetable,
Animal and Inorganic Worlds.)
The plant gathers these inorganic materials together and makes them up
into its own substance. The animal eats the plant and appropriates the
nutritious portions to its own sustenance, rejects and gets rid of the
useless matters; and, finally, the animal itself dies, and its whole body
is decomposed and returned into the inorganic world. There is thus a
constant circulation from one to the other, a continual formation of
organic life from inorganic matters, and as constant a return of the
matter of living bodies to the inorganic world; so that the materials of
which our bodies are composed are largely, in all probability, the
substances which constituted the matter of long extinct creations, but
which have in the interval constituted a part of the inorganic world.
Thus we come to the conclusion, strange at first sight, that the
MATTER constituting the living world is identical with that which
forms the inorganic world. And not less true is it that, remarkable as are
the powers or, in other words, as are the FORCES which are exerted by
living beings, yet all these forces are either identical with those which

exist in the inorganic world, or they are convertible into them; I mean
in just the same sense as the researches of physical philosophers have
shown that heat is convertible into electricity, that electricity is
convertible into magnetism, magnetism into mechanical force or
chemical