temperature from falling below this standard. On the contrary, if the
circulation is quickened by muscular exertion, the warmer blood flowing
from the internal organs into the capillaries, raises the temperature of
the skin, secretion is augmented, the moisture exudes from the pores,
and perceptible evaporation begins. A large portion of the animal heat
is thrown off in this process, and the temperature of the skin is
reduced. A very warm, dry atmosphere can be borne with impunity but if
moisture is introduced, evaporation ceases, and the life of the animal
is endangered. Persons have been known to remain in a temperature of
about 300° Fahr. for some minutes without unpleasant effects. Three
conditions may be assigned as effective causes in retarding or
augmenting this cutaneous secretion, variations in the temperature of
the atmosphere, muscular activity, and influences which affect the
nerves. The emotions exert a remarkable influence upon the action of the
perspiratory glands. Intense fear causes great drops of perspiration to
accumulate on the skin, while the salivary glands remain inactive.

TEARS. The lachrymal glands are small lobular organs, situated at the
outer and upper orbit of the eye, and have from six to eight ducts,
which open upon the conjunctiva, between the eyelid and its inner fold.
This secretion is an alkaline, watery fluid. According to Dr. Dalton,
its composition is as follows:

Water, 882.0
Albuminous matter, 5.0
Chloride of Sodium, 13.0
Mineral Salts, a trace,
------
1000.0