80
to 0; and, on the contrary, the subtraction of stimulant power will
allow the excitability to accumulate.

[DIAGRAM]

The range of good health is ranked from 30 to 50 degrees in the
scale; for perfect health, which consists in the middle point only,
or at 40 degrees, rarely occurs; in consequence of the variation of
the stimuli to which man is continually exposed, such as meat and
drink, heat, exercise, and the emotions of the mind, the excitement
commonly fluctuates between 30 and 50 degrees, and yet no particular
disturbance of the functions takes place. But when at these points,
30 or 50, predisposition commences, the slightest debilitating cause
in the former case, and the slightest stimulating cause in the
latter, brings on disease, in which the functions begin to be
disturbed in various ways, and this disturbance is always in
proportion to the hurting powers which have produced the disease, and
the delicacy or importance of the part affected.

The effect produced on the excitability by any stimulus, must
evidently be in a ratio compounded of the degree of excitability and
the force of the stimulus. The same stimulus will produce greater
contractions upon a fibre that is more irritable than upon one which
possesses less irritability; and the irritability or excitability of
the fibre being given, or remaining the same, the contraction will be
in proportion to the strength of the stimulus. Hence it is evident,
that the effect or excitement must be in a ratio compounded of the
exciting powers and excitability.

Sthenic diathesis and disease is caused by the operation of different
exciting powers, which produce too great a degree of excitement in
the system: this at first increases all the functions, and, when
increased, produces a disturbance and inordinate action of them,
which is communicated to the whole body. In diseases of this kind
there is often an appearance of debility, but this is extremely
fallacious, and arises from the disturbed state of the different
functions. Hence it is evidently of the utmost consequence to
ascertain carefully whether this debility is real, or the effect of
asthenic disease: or whether it is owing to the disturbance of the
functions by over stimulating, and in this case fallacious; for
should a sthenic disease be treated by stimulants and cordials, the
effect would be an aggravation of all the symptoms, and a much higher
degree of disease.

Asthenic diathesis and disease