fag.

This clears the ground of a good many ancient misconceptions; for
instance, that the chief cause of pneumonia is direct exposure to cold
or a wetting, or the inhalation of raw, cold air. Few beliefs were more
firmly fixed in the popular mind--and, for the matter of that, in the
medical--up to fifteen or twenty years ago. It has found its way into
literature; and the hero of the shipwreck in an icy gale or of weeks of
wandering in the Frozen North, who must be offered up for artistic
reasons as a sacrifice to the plot, invariably dies a victim of
pneumonia, from his "frightful exposure," just as the victim of
disappointed love dies of "a broken heart," or the man who sees the
ambitions of years come crashing about his ears, or the woman who has
lost all that makes life worth living, invariably develops "brain
fever."

There is a physical basis for all of these standard catastrophes, but it
is much slenderer than is usually supposed. For instance, almost every
one can tell you how friends of theirs have "brought on congestion of
the lungs," or pneumonia, by going without an overcoat on a winter day,
or breaking through the ice when skating, or even by getting their feet
wet and not changing their stockings; and this single dramatic instance
has firmly convinced them that the chief cause of "lung fever" is a
chill or a wetting. Yet when we come to tabulate long series of causes,
rising into thousands, we find that the percentage in which even the
patients themselves attribute the disease to exposure, or a chill, sinks
to a surprisingly small amount. For instance, in the largest series
collected with this point in mind, that of Musser and Norris, out of
forty-two hundred cases only seventeen per cent gave a history of
exposure and "catching cold"; and the smaller series range from ten to
fifteen per cent. So that, even in the face of the returns, not more
than one-fifth of all cases of pneumonia can reasonably be attributed to
chill. And when we further remember that under this heading of exposure
and "catching cold" are included many mere coincidences and the chilly
sensations attending the beginning of those milder infections which we
term "common colds," it is probable that even this small percentage
could be reduced one-half. Indeed, most cautious investigators of the
question have expressed themselves to this effect. This harmonizes with
a number of obstinate facts which have long proved stumbling-blocks in
the