This is the organism of generation.

These three organisms, brought into the most thorough connection, local
and real, go to form the human body.



S 3.--The Body.


The organic powers of the human body naturally divide themselves into two
principal classes. The first class embraces those which no known laws
and phenomena of the physical world enable us to comprehend; and to these
belong the sensibility of the nerves and the irritability of the muscles.
Inasmuch as it has hitherto been impossible to penetrate the economy of
the invisible, men have sought to interpret this unknown mechanism
through that with which they were already familiar, and have considered
the nerves as a canal conducting an excessively fine, volatile, and
active fluid, which in rapidity of motion and fineness was held to excel
ether and the electric spark. This fluid was held to be the principle
and author of our sensibility and power of motion, and hence received the
name of the spirit of life. Further, the irritability of the muscles was
held to consist, in a certain effort to contract themselves on the touch
of some external provocation. These two principles go to form the
specific character of animal organism.

The second class of powers embraces those which we can account for by the
universally-known laws of physics. Among these I reckon the mechanism of
motion, and the chemistry of the human body, the source of vegetable
life. Vegetation, then, and animal mechanism, thoroughly mingled, form