is suspended.

In exposure to the lowest wave of temperature in this country these
extreme effects are not commonly developed; but minor effects are
brought out which are most significant. In particular, the effect on
the lungs is strongly marked. The capillary vessels of the lungs,
making up that fine network which plays over the computed six hundred
millions of air vesicles, undergo paralysis when the cold air enters,
and in proportion as such obstruction from this cause is decisive, the
blood that should be brought to the air vesicles is impeded, and the
process of oxidation is mechanically as well as chemically suppressed.
The same contraction is also exerted on the vessels of the skin,
driving the blood into the interior and better protected organs. Hence
the reason why on leaving a warm room to enter a cold frosty air there
is an immediate action of the visceral organs from pressure of blood
on them, and not unfrequently a tendency to diarrhoea from temporary
congestion of the digestive tract. Three factors are at work, in fact,
whenever the low wave of temperature affects the animal body;
abstraction of heat from the body, beyond what is natural; arrest of
chemical action and of combustion; paralysis of the minute vessels
exposed to the cold.


COMBINED EFFECTS.

We cannot view the extent of change in the organic life induced by the
low wave of heat without seeing at once the sweep of mischief which
exposure to the wave may effect. It exerts an influence on healthy
life in the middle-aged man, and I know of no disease which it does
not influence disastrously. Is the healthy man exhausted, it favors