embling
limbs, by whistling, or singing, as they pass by a country
churchyard, and the soldier feels his departing courage recalled in
the onset of a battle, by the "spirit stirring drum."

Intoxication is generally attended with a higher degree of life or
excitement than is natural. Now sound will produce this effect with a
very moderate portion of fermented liquor; hence we find persons much
more easily intoxicated and highly excited at public entertainments,
where there is music and loud talking, than in private companies,
where no auxiliary stimulus is added to that of wine.

Persons who are destitute of hearing and seeing, possess life in a
more languid state than other people; which is, in a great degree,
owing to the want of the stimulus of light and noise.

Odours have likewise a very sensible effect in promoting animal life.
The effects of these will appear obvious in the sudden revival of
life, which they produce, in cases of fainting. The smell of a few
drops of hartshorn, or even a burnt feather, has frequently, in a few
minutes, restored the system from a state of weakness, bordering upon
death, to an equable and regular degree of excitement.

All these different stimuli undoubtedly produce the greatest effects
upon their proper organs; thus the effect of light is most powerful
on the eye; that of sound on the ear; that of food on the stomach,
&c. But their effects are not confined to these organs, but extended
over the whole body. The excitability exists, one and indivisible,
over the whole system; we may call it sensibility, or feeling, to
enable us to understand the subject. Every organ, or indeed the whole
body, is endowed with this property in a greater or less degree, so
that the effects produced by any stimulus, though they are more
powerful on the part where they are applied, affect the whole system:
odours afford an instance of this; and the prick of a pin in the
finger, produces excitement, or a stimulant effect, over the whole
body.

From what has been said, it must be evident that life is the effect
of a number of external powers, constantly acting on the body,
through the medium of that property which we call excitability; that
it cannot exist independent of the action of these stimuli; when they
are withdrawn, though the excitability does not instantly vanish,
there is no life, no motion, but the semblance of death. Life,
therefore, is constantly supported by, and depends constantly on,