Since the
earth is immovable, the body is lifted or pushed upward, somewhat as
a fulcrum support is made to move when it is too weak to hold up the
weight that is being lifted. In other words, we have the same lever
action in the foot in lifting the body as we have when one lies face
downward, and, bending the knee, lifts some object on the toes.

_ 88 Walking_ is considered one of the very best forms of counter-active
exercise for the brain worker (page 328).

89 The epidermis does not afford complete protection against chemicals,
many of them being able to destroy it quickly. The rule of washing
the skin immediately after contact with strong chemical agents
should always be followed.

90 "Rough calculations have placed the number of sweat glands on the
entire body at about 2,000,000." Rettger, _Studies in Advanced
Physiology_.

91 Heat also leaves the body by the lungs, partly by the respired air
and partly through the evaporation of moisture from the lung
surfaces. Respiration in some animals, as the dog, is the chief
means of cooling the body.

92 "The story is told of some woodsmen who were overtaken by a severe
snowstorm and had to spend the night away from camp; they had a
bottle of whisky, and, chilled to the bone, some imbibed freely
while others refused to drink. Those who drank soon felt comfortable
and went to sleep in their improvised shelter; those who did not
drink felt very uncomfortable throughout the night and could get no
sleep, but in the morning they were alive and able to struggle back
to camp, while their companions who had used alcohol were frozen to
death.... This, if true, was of course an extreme case; but it
accords with the universal experience of arctic travelers and of
lumbermen and hunters in the northern woods, that the use of alcohol
during exposure to cold, although contributing greatly to one's
comfort for the time being, is generally followed by undesirable or
dangerous results."--HOUGH AND SEDGWICK: _The Elements of Hygiene and
Sanitation_.

93 Foods that are difficult to digest, or which cause disturbances of
the digestive organs (a coated tongue being one indication), have a
bad effect upon the skin. It is in this way that the use of tea and
coffee by some people induces a s