om paucity of blood. Weak contractions performed in less time, and
with shorter intervals._ 5. _Last situation of the fibres continues
after contraction._ 6. _Contraction greater than usual induces pleasure
or pain._ 7. _Mobility of the fibres uniform. Quantity of sensorial
power fluctuates. Constitutes excitability._ II. Of sensorial exertion.
1. _Animal motion includes stimulus, sensorial power, and contractile
fibres. The sensorial faculties act separately or conjointly. Stimulus
of four kinds. Strength and weakness defined. Sensorial power
perpetually exhausted and renewed. Weakness from defect of stimulus.
From defect of sensorial power, the direct and indirect debility of Dr.
Brown. Why we become warm in Buxton bath after a time, and see well
after a time in a darkish room. Fibres may act violently, or with their
whole force, and yet feebly. Great exertion in inflammation explained.
Great muscular force of some insane people._ 2. _Occasional
accumulation of sensorial power in muscles subject to constant
stimulus. In animals sleeping in winter. In eggs, seeds, schirrous
tumours, tendons, bones._ 3. _Great exertion introduces pleasure or
pain. Inflammation. Libration of the system between torpor and
activity. Fever-fits._ 4. _Desire and aversion introduced. Excess of
volition cures fevers._ III. Of repeated stimulus. 1. _A stimulus
repeated too frequently looses effect. As opium, wine, grief. Hence old
age. Opium and aloes in small doses._ 2. _A stimulus not repeated too
frequently does not lose effect. Perpetual movement of the vital
organs._ 3. _A stimulus repeated at uniform times produces greater
effect. Irritation combined with association._ 4. _A stimulus repeated
frequently and uniformly may be withdrawn, and the action of the organ
will continue. Hence the bark cures agues, and strengthens weak
constitutions._ 5. _Defect of stimulus repeated at certain intervals
causes fever-fits._ 6. _Stimulus long applied ceases to act a second
time._ 7. _If a stimulus excites sensation in an organ not usually
excited into sensation, inflammation is produced._ IV. Of stimulus
greater than natural. 1. _A stimulus greater than natural diminishes
the quantity of sensorial power in general._ 2. _In particular organs._
3. _Induces the organ into spasmodic actions._ 4. _Induces the
antagonist fibre