owing to the action of cold, I will deny; nay, I will assert,
that if a person go out into air which is very cold, _and remain in
it_ for a very long time, he will never perceive any symptoms of
what is called a cold so long as he remains there.

A common cold is attended with a running of the nose, hoarseness,
and cough, with a considerable degree of feverish heat, an dryness
of the skin.--Now it is universally agreed, that this disorder is an
inflammation, or is of an inflammatory nature; it is an inflammation
of the smooth, moist skin which lines the nostrils, and goes down
the wind-pipe into the lungs; but as cold is only a diminution of
heat, or a diminution of a stimulus acting upon the body, it is
impossible that such a diminution can cause a greater action or
excitement; we might as well expect to fill a vessel by taking water
out of it. But let us see how a cold, as it is commonly called, is
usually produced. When a person in cold weather goes out into the
air, every time he draws in his breath, the cold air passes through
his nostrils and windpipe into the lungs, and in thus diminishing
the heat of the parts, allows their excitability to accumulate, and
renders them more liable to be affected by the succeeding heat. So
long as that person continues in the cold air, he feels no bad
effects; but if he come into a warm room, he first perceives a glow
within his nostrils and breast, as well as all over the surface of
the body. Soon afterwards, a disagreeable dryness and huskiness will
be felt in the nostrils and breast. By and by a short, dry, tickling
cough comes on. He feels a shivering, which makes him draw nearer to
the fire, but all to no purpose; the more he tries to heat himself,
the more chill he becomes. All the mischief is here caused by the
violent action of the heat on the accumulated excitability. For want
of a knowledge of this law, these disagreeable, and often dangerous