elements, has ever made a living plant, much less a living animal. No
better comparison has ever been given than that of Youmans, who makes a
table of the analogies between the human body and the steam-engine, which
I give as it stands.


ANALOGIES OF THE STEAM-ENGINE AND THE LIVING BODY.

_The Steam Engine in Action takes_:

1. Fuel: coal and wood, both combustible.

2. Water for evaporation.

3. Air for combustion.


_And Produces_:

4. A steady boiling heat of 212° by quick combustion.

5. Smoke loaded with carbonic acid and watery vapor.

6. Incombustible ashes.

7. Motive force of simple alternate push and pull in the piston, which,
acting through wheels, bands, and levers, does work of endless variety.

8. A deficiency of fuel, water, or air, disturbs, then stops the motion.