oss of heat by keeping in contact with
it a layer of still air, which is an exceedingly bad conductor. When a man
feels too warm and throws off his coat, he removes one of the badly
conducting layers of air, and increases the heat loss by radiation and
conduction. The vapor next the skin is thus allowed a freer access to the
surface, and the loss of heat by evaporation of the sweat becomes greater.
This voluntary factor by which the equilibrium is maintained must be
regarded as of great importance. This power also exists in the lower
animals, but to a much smaller extent. Thus a dog, on a hot day, runs out
his tongue and stretches his limbs so as to increase the surface from
which heat is radiated and conducted.

The production, like the loss, of heat is to a certain extent under the
control of the will. Work increases the production of heat, and rest,
especially sleep, lessens it. Thus the inhabitants of very hot countries
seek relief during the hottest part of the day by a siesta. The quantity
and quality of food also influence the production of heat. A larger
quantity of food is taken in winter than in summer. Among the inhabitants
of the northern and Arctic regions, the daily consumption of food is far
greater than in temperate and tropical climates.

228. Effect of Alcohol upon the Lungs. It is a well recognized fact
that alcohol when taken into the stomach is carried from that organ to the
liver, where, by the baneful directness of its presence, it produces a
speedy and often disastrous effect. But the trail of its malign power does
not disappear there. From the liver it passes to the right side of the
heart, and thence to the lungs, where its influence is still for harm.

In the lungs, alcohol tends to check and diminish the breathing capacity
of these organs. This effect follows from the partial paralyzing influence
of the stupefying agent upon the sympathetic nervous system, diminishing
its sensibility to the impulse of healthful respiration. This diminished
capacity for respiration is clearly shown by the use of the _spirometer_,
a simple instrument which accurately records the cubic measure of the
lungs, and proves beyond denial the decrease of the lung space.

"Most familiar and most dangerous is the drinking man's inability to
resist lung diseases."--Dr. Adoph Frick, the eminent German physiologist
of Zurich.

"Alcohol, instead of preventing consumption, as was once believed,
reduces the vital