2. _Of Grief._

That the internal membrane of the nostrils may be kept always moist, for
the better perception of odours, there are two canals, that conduct the
tears after they have done their office in moistening and cleaning the ball
of the eye into a sack, which is called the lacrymal sack; and from which
there is a duct, that opens into the nostrils: the aperture of this duct is
formed of exquisite sensibility, and when it is stimulated by odorous
particles, or by the dryness or coldness of the air, the sack contracts
itself, and pours more of its contained moisture on the organ of smell. By
this contrivance the organ is rendered more fit for perceiving such odours,
and is preserved from being injured by those that are more strong or
corrosive. Many other receptacles of peculiar fluids disgorge their
contents, when the ends of their ducts are stimulated; as the gall bladder,
when the contents of the duodenum stimulate the extremity of the common
bile duct: and the salivary glands, when the termination of their ducts in
the mouth are excited by the stimulus of the food we masticate. Atque
vesiculæ seminales suum exprimunt fluidum glande penis fricatâ.

The coldness and dryness of the atmosphere, compared with the warmth and
moisture, which the new-born infant had just before experienced,
disagreeably affects the aperture of this lacrymal sack: the tears, that
are contained in this sack, are poured into the nostrils, and a further
supply is secreted by the lacrymal glands, and diffused upon the eye-balls;
as is very visible in the eyes and nostrils of children soon after their
nativity. The same happens to us at our maturer age, for in severe frosty
weather, snivelling and tears are produced by the coldness and dryness of
the air.

But the lacrymal glands, which separate the tears from the blood, are