affected, on the body, is the loss of colour in the hair, which has
occasionally been observed after extreme terror or grief. One authentic
instance has been recorded, in the case of a man brought out for
execution in India, in which the change of colour was so rapid that it
was perceptible to the eye.[301]
Another good case is that of the trembling of the muscles, which is
common to man and to many, or most, of the lower animals. Trembling is
of no service, often of much disservice, and cannot have been at first
acquired through the will, and then rendered habitual in association
with any emotion. I am assured by an eminent authority that young
children do not tremble, but go into convulsions under the
circumstances which would induce excessive trembling in adults.
Trembling is excited in different individuals in very different degrees
and by the most diversified causes, by cold to the surface, before
fever-fits, although the temperature of the body is then above the
normal standard; in blood-poisoning, delirium tremens, and other
diseases; by general failure of power in old age; by exhaustion after
excessive fatigue; locally from severe injuries, such as burns; and, in
an especial manner, by the passage of a catheter. Of all emotions, fear
notoriously is the most apt to induce trembling; but so do occasionally
great anger and joy. I remember once seeing a boy who had just shot his
first snipe on the wing, and his hands trembled to such a degree from
delight, that he could not for some time reload his gun; and I have
heard of an exactly similar case with an Australian savage, to whom a
gun had been lent. Fine music, from the vague emotions thus excited,
causes a shiver to run down the backs of some persons. There seems to
be very little in common in the above several physical causes and
emotions to account for trembling; and Sir J. Paget, to whom I am
indebted for several of the above statements, informs me that the
subject is a very obscure one. As trembling is sometimes caused by
rage, long before exhaustion can have set in, and as it sometimes
accompanies great joy, it would appear that any strong excitement of
the nervous system interrupts the steady flow of nerve-force to the
muscles.[302]
The manner in which the secretions of the alimentary canal and of
certain glands as the liver, kidneys, or mamm are affected by strong
emotions, is another excellent instance of the direct action of the
sensorium on these organs, independently of the will or of any
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