OF THE SYMPATHIES OF MUCOUS MEMBRANES.
66. I distribute the sympathies of mucous membranes, like those of
most of the other organs, into three general classes. In the first
class are ranked the sympathies in which irritation, on one part of
the mucous surface, produces a sensation in a distant part. A stone
in the bladder occasions pain at the end of glans; worms in the
intestines excite an itching at the nose. Whytt has seen a painful
affection induced over the whole side of the head by a foreign
body in the ear; an ulcer in the bladder produces a pain in the
superior parts of the thighs every time that the patient passes his
urine.
67. I refer to the second class those sympathies in which the
irritation of one point on mucous surfaces produces irritability
in a different structure; thus, too lively an impression on the
pituitary membrane occasions sneezing; the irritation of the
bronchi coughing; biliary concretions produce spasmodic vomiting;
stones in the bladder occasion retraction of the testicle towards
the ring. In all these cases there is contraction of the muscles
produced by the irritation of the mucous surface, distant from the
place in which that contraction occurs.
68. The last class of the sympathies of mucous membranes embraces
those in which the irritation of any part of their extension
determines elsewhere the exercise of their tonicity. Here we must
refer to what we have said upon glandular action being augmented
by the irritation of the extremities of the excretory ducts. Thus
it is evident, that the increase of the tonic power of the parotid
for the secretion of the saliva, and of its excretory duct in order
to transmit it, when the extremity of this duct is irritated by
food, sialogogue medicines, &c.,--it is evident, I say, that this
augmentation is a phenomenon purely sympathetic. We may designate
each of these three classes by the name of the vital power which
they bring into action, calling the first sympathy of sensibility;
the second, sympathy of irritability; and the third, sympathy of
tonicity.
69. This manner of classing the sympathies is entirely borrowed
from the state of the vital powers, of which they are but irregular
modifications, and only aberrations, still unknown in their
nature. Nevertheless it is subject to very great inconveniences:
yet it appears to me to be preferable to that of Whytt, who simply
follows the order of the regions; and even to that of Barthy, who,
more methodical, examines them successively in the organs connected
by systems, in those which are insulated, and in those situated in
symmetrical halves of the body.