ut of these same forms of ordinary matter, and from
none which are simpler, the vegetable world builds up all the protoplasm
that keeps the animal world a-going. Plants are the accumulators of the
power which animals distribute and disperse.

But it will be observed that the existence of the matter of life depends
on the preexistence of certain compounds; namely, carbonic acid, water,
and ammonia. Withdraw any one of these three from the world, and all vital
phenomena come to an end. They are related to the protoplasm of the plant,
as the protoplasm of the plant is to that of the animal. Carbon, hydrogen,
oxygen, and nitrogen are all lifeless bodies. Of these, carbon and oxygen
unite in certain proportions, and under certain conditions, to give rise
to carbonic acid; hydrogen and oxygen produce water; nitrogen and hydrogen
give rise to ammonia. These new compounds, like the elementary bodies of
which they are composed, are lifeless. But when they are brought together,
under certain conditions, they give rise to the still more complex body,
protoplasm, and this protoplasm exhibits the phenomena of life.

I see no break in this series of steps in molecular complication, and I am
unable to understand why the language which is applicable to any one term
of the series may not be used with any of the others. We think fit to call
different kinds of matter carbon, oxygen, hydrogen, and nitrogen, and to
speak of the various powers and activities of these substances as the
properties of the matter of which they are composed.

When hydrogen and oxygen are mixed in a certain proportion, and an
electric spark is passed through them, they disappear, and a quantity of
water, equal in weight to the sum of their weights, appears in their
place. There is not the slightest parity between the passive and active
powers of the water and those of the oxygen and hydrogen which have given
rise to it. At 32 degrees Fahrenheit, and far below that temperature,
oxygen and hydrogen are elastic gaseous bodies, whose particles tend to
rush away from one another with great force. Water, at the same
temperature, is a strong though brittle solid, whose particles tend to
cohere into definite geometrical shapes, and sometimes build up frosty
imitations of the most complex forms of vegetable foliage.

Nevertheless we call these, and many other strange phenomena, the
properties of the water, and we do not hesitate to believe that, in some
way or another, t