ity of
animal power residing in the muscular fibres. These tremors only exist when
the affected muscles are excited into action, as in lifting a glass to the
mouth, or in writing, or in keeping the body upright; and cease again, when
no voluntary exertion is attempted, as in lying down. Hence these tremors
evidently originate from the too quick exhaustion of the lessened quantity
of the spirit of animation. So many people tremble from fear or anger, when
too great a part of the sensorial power is exerted on the organs of sense,
so as to deprive the muscles, which support the body erect, of their due
quantity.

4. _Brachiorum paralysis._ A numbness of the arms is a frequent symptom in
hydrops thoracis, as explained in Class I. 2. 3. 14. and in Sect. XXIX. 5.
2.; it also accompanies the asthma dolorificum, Class III. 1. 1. 11. and is
owing probably to the same cause in both. In the colica saturnina a
paralysis affects the wrists, as appears on the patient extending his arm
horizontally with the palm downwards, and is often attended with a tumor on
the carpal or metacarpal bones. See Class IV. 1. 2. 10.

Mr. M----, a miner and well-sinker, about three years ago, lost the power
of contracting both his thumbs; the balls or muscles of the thumbs are much
emaciated, and remain paralytic. He ascribes his disease to immersing his
hands too long in cold water in the execution of his business. He says his
hands had frequently been much benumbed before, so that he could not
without difficulty clench them; but that they recovered their motion, as
soon as they began to glow, after he had dried and covered them.

In this case there existed two injurious circumstances of different kinds;
one the violent and continued action of the muscles, which destroys by
exhausting the sensorial power; and the other, the application of cold,
which destroys by defect of stimulus. The cold seems to have contributed to
the paralysis by its long application, as well as the continued exertion;
but as during the torpor occasioned by the exposure to cold, if the degree
of it be not so great as to extinguish life, the sensorial power becomes
accumulated; there is reason to believe, that the exposing a paralytic limb
to the cold for a certain time, as by covering it with snow or iced water
for a few minutes, and then covering it with warm flannel, and this
frequently repeated, might, by accumulation of sensorial power, contribute
to restore it to a state of