rs, or even in drafty hallways, but
in close, stuffy, infected hotel bedrooms, sleeping-cars, churches, and
theatres.

Two arguments in rebuttal will at once be brought forward, both
apparently conclusive. One is that colds are vastly more frequent in
winter, and the other that when you sit in a draft until you feel
chilly, you inevitably have a cold afterward. Both these arguments
alike, however, are based upon a misunderstanding. The frequency of
colds in winter is chiefly due to the fact that, at this time of the
year, we crowd into houses and rooms, shutting the doors and windows in
order to keep warm, and thus provide a ready-made hothouse for the
cultivation and transmission from one to another of the influenza and
other bacilli. As the brilliant young English pulmonary expert, Dr.
Leonard Williams, puts it, "a constant succession of colds implies a
mode of life in which all aerial microbes are afforded abundant
opportunities." At the same time, we take less exercise and sit far less
in the open air, thus lowering our general vigor and resisting power and
making us more susceptible to attack. Those who live out-of-doors winter
and summer, and who ventilate their houses properly, even in cold
weather, suffer comparatively little more from colds in the winter-time
than they do in summer; although, of course, the most vigorous
individual, in the best ventilated surroundings, will occasionally
succumb to some particularly virulent infection.

The second fact of experience, catching cold after sitting in a draft or
a chilly room until you begin to cough or sneeze, is one to which a
majority of us would be willing to testify personally, and yet it is
based upon something little better than an illusion. It is a well-known
peculiarity of many fevers and infections to begin with a chill. The
patient complains of shiverings up and down his spine, his fingernails
and his lips become blue, in extreme cases his teeth chatter, and his
limbs begin to twitch and shake, and he ends up in a typical ague fit.
The best known, because most striking, illustration is malaria, or fever
and ague, "chills and fever," as it is variously termed. But this form
of attack, milder and much slighter in degree, may occur in almost every
known infection, such as pneumonia, typhoid, tuberculosis, scarlet
fever, measles, and influenza. It has nothing whatever to do with either
external or internal temperature; for if you slip a fever-thermometer
un