mely, those diseases supposed to be
caused by exposure to the weather. Even here, it still has a
considerable basis in fact; but the general trend of opinion among
thoughtful physicians is that this basis is much narrower than was at
one time supposed, and is becoming still more restricted with the
progress of scientific knowledge. For instance, fifty years ago, popular
opinion, and even the majority of medical belief, was that consumption
and all of its attendant miseries were chiefly due to exposure to cold.
Now we know that, on the contrary, abundance of pure, fresh, cold air is
the best cure for the disease, and foul air and overcrowding its chief
cause. An almost equally complete about-face has been executed in regard
to pneumonia. Prolonged and excessive exposure to cold may be the match
that fires the mine, but we are absolutely certain that two other things
are necessary, namely, the presence of the diplococcus, and a lowered
and somewhat vitiated state of bodily resistance, due to age, overwork,
underfeeding, or over-indulgence in alcohol.

Not only do these two diseases not occur in the land of perpetual cold,
the frozen North, except where they are introduced by civilized
visitors,--and scarce a single death from pneumonia has ever yet
occurred in the crew of an Arctic expedition,--but it has actually been
proposed to fit up a ship for a summer trip through the Arctic regions,
as a floating sanatorium for consumptives, on account of the purity of
the air and the brilliancy of the sunlight.

There is one realm, however, where the swing of this ancient
superstition vibrates with fullest intensity, and that is in those
diseases which, as their name implies, are still believed to be due to
exposure to a lowered temperature--"common colds." Here again it has a
certain amount of rational basis, but this is growing less and less
every day. The present attitude of thoughtful physicians may be
graphically indicated by the flippant inquiry of the riddle-maker, "When
is a cold not a cold?" and the answer, "Two-thirds of the time." This
much we are certain of already: that the majority of so-called "colds"
have little or nothing to do with exposure to a low temperature, that
they are entirely misnamed, and that a better term for them would be
_fouls_. In fact, this proportion can be clearly and definitely proved
and traced as infections spreading from one victim to another. The best
place to catch them is not out-of-doo