It is generally believed that the peristaltic movements of the
intestines are influenced by attention being paid to them at fixed
recurrent periods; and these movements depend on the contraction of
unstriped and involuntary muscles. The abnormal action of the voluntary
muscles in epilepsy, chorea, and hysteria is known to be influenced by
the expectation of an attack, and by the sight of other patients
similarly affected. So it is with the involuntary acts of yawning and
laughing.
Certain glands are much influenced by thinking of them, or of the
conditions under which they have been habitually excited. This is
familiar to every one in the increased flow of saliva, when the
thought, for instance, of intensely acid fruit is kept before the mind.
It was shown in our sixth chapter, that an earnest and long-continued
desire either to repress, or to increase, the action of the lacrymal
glands is effectual. Some curious cases have been recorded in the case
of women, of the power of the mind on the mammary glands; and still
more remarkable ones in relation to the uterine functions.
See Gratiolet on this subject, De la Phys. p. 287. Dr. J. Crichton
Browne, from his observations on the insane, is convinced that
attention directed for a prolonged period on any part or organ may
ultimately influence its capillary circulation and nutrition. He has
given me some extraordinary cases; one of these, which cannot here be
related in full, refers to a married woman fifty years of age, who
laboured under the firm and long-continued delusion that she was
pregnant. When the expected period arrived, she acted precisely as if
she had been really delivered of a child, and seemed to suffer extreme
pain, so that the perspiration broke out on her forehead. The result
was that a state of things returned, continuing for three days, which
had ceased during the six previous years. Mr. Braid gives, in his
Magic, Hypnotism, &c., 1852, p. 95, and in his other works analogous
cases, as well as other facts showing the great influence of the will
on the mammary glands, even on one breast alone.
When we direct our whole attention to any one sense, its acuteness is
increased;[1340] and the continued habit of close attention, as with
blind people to that of hearing, and with the blind and deaf to that of
touch, appears to improve the sense in question permanently. There is,
also, some reason to believe, judging from the capacities of different
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