re
supposed to be exhibited in their usual doses, otherwise they become
drastic purges, and are treated of in the Class of Invertentia.

VI. The mucus of the bladder is seen in the urine, when cantharides have
been used, either internally or externally, in such doses as to induce the
strangury. Spirit of turpentine is said to have the same effect. I have
given above a dram of it twice a day floating on a glass of water in
chronic lumbago without this effect, and the patient gradually recovered.

VII. Aloe given internally seems to act chiefly on the rectum and, spincter
ani, producing tenesmus and piles. Externally in clysters or suppositories,
common salt seems to act on that bowel with greater certainty. But where
the thread-worm or ascarides exist, 60 or 100 grains of aloes reduced to
powder and boiled in a pint of gruel, and used as a clyster twice a week
for three months, has frequently destroyed them.

VIII. The external application of cantharides by stimulating the excretory
ducts of the capillary glands produces a great secretion of subcutaneous
mucus with pain and inflammation; which mucaginous fluid, not being able to
permeate the cuticle, raises it up; a similar secretion and elevation of
the cuticle is produced by actual fire; and by caustic materials, as by the
application of the juice of the root of white briony, or bruised
mustard-seed. Experiments are wanting to introduce some acrid application
into practice instead of cantharides, which might not induce the strangury.

Mustard-seed alone is too acrid, and if it be suffered to lie on the skin
many minutes is liable to produce a slough and consequent ulcer, and should
therefore be mixed with flour when applied to cold extremities. Volatile
alkali properly diluted might stimulate the skin without inducing
strangury.

IX. The mild errhines are such as moderately stimulate the membrane of the
nostrils, so as to increase the secretion of nasal mucus; as is seen in
those, who are habituated to take snuff. The stronger errhines are
mentioned in Art. V. 2. 3.

X. The secretion of tears is increased either by applying acrid substances
to the eye; or acrid vapours, which stimulate the excretory duct of the
lacrymal gland; or by applying them to the nostrils, and stimulating the
excretory duct of the lacrymal sack, as treated of in the Section on
Instinct.

Or the secretion of tears is increased by the association of the motions of
the excretory duct of the