th but little trouble and expense, might be kept and do good
service for years. The object is to replace the teeth with an artificial
set. Very few plates, either partial or entire, are worn with real
comfort. They should always be removed before going to sleep, as there is
danger of their being swallowed.

The great majority of drugs have no injurious effect upon the teeth. Some
medicines, however, must be used with great care. The acids used in the
tincture of iron have a great affinity for the lime salts of the teeth. As
this form of iron is often used, it is not unusual to see teeth very badly
stained or decayed from the effects of this drug. The acid used in the
liquid preparations of quinine may destroy the teeth in a comparatively
short time. After taking such medicines the mouth should be thoroughly
rinsed with a weak solution of common soda, and the teeth cleansed.

170. Alcohol and Digestion. The influence of alcoholic drinks upon
digestion is of the utmost importance. Alcohol is not, and cannot be
regarded from a physiological point of view as a true food. The reception
given to it by the stomach proves this very plainly. It is obviously an
unwelcome intruder. It cannot, like proper foods, be transformed into any
element or component of the human body, but passes on, innutritious and
for the most part unappropriated. Taken even into the mouth, by any person
not hardened to its use, its effect is so pungent and burning as at once
to demand its rejection. But if allowed to pass into the stomach, that
organ immediately rebels against its intrusion, and not unfrequently
ejects it with indignant emphasis. The burning sensation it produces
there, is only an appeal for water to dilute it.

The stomach meanwhile, in response to this fiery invitation, secretes from
its myriad pores its juices and watery fluids, to protect itself as much
as possible from the invading liquid. It does not digest alcoholic drinks;
we might say it does not attempt to, because they are not material
suitable for digestion, and also because no organ can perform its normal
work while smarting under an unnatural irritation.

Even if the stomach does not at once eject the poison, it refuses to
adopt it as food, for it does not pass along with the other food material,
as chyme, into the intestines, but is seized by the absorbents, borne into
the veins, which convey it to the heart, whence the pulmonary artery
conveys it to the lungs, where its