art and arteries are violently increased, and of all the moving system
along with them. Thus the peripneumony is generally induced by the patient
respiring very cold air, and this especially after being long confined to
warm air, or after being much fatigued and heated by excessive labour or
exercise. For we can cover the skin with more clothes, when we feel
ourselves cold; but the lungs not having the perception of cold, we do not
think of covering them, nor have the power to cover them, if we desired it;
and the torpor, thus produced is greater, or of longer duration, in
proportion to the previous expenditure of sensorial power by heat or
exercise.

This torpor of the lungs affects the skin with shuddering, and the stomach
is also secondarily affected; next follows the violent action of the lungs
from the accumulation of the power of irritation, and an inflammation of
them follows this violent action. While the stomach recovers its activity
by the increase of the excitement of the sensorial power of association,
and along with it the heart and arteries, and the whole moving system.
Hence this inflammation occurs during the hot fit of fever, and no cold fit
succeeds, because the excess of the sensorial power of sensation prevents a
succeeding torpor.

These new motions of certain parts of the system produce increased
secretions of nutritious or organic mucus, which forms new vessels; these
new vessels by their unusual motions produce new kinds of fluids; which are
termed contagious, because they have the power, when introduced into a
healthy body, of producing similar actions and effects, with or without
fever, as in the small-pox and measles, or in the itch and venereal
disease.

If any of these contagious matters affect the stomach with torpor either by
their stimulus immediately applied, or by its sympathy with the parts first
diseased, a fever is produced with sickness and want of appetite; as in
small-pox, and scarlatina. If the stomach is not affected by contagious
matter, no fever succeeds, as in itch, tinea, syphilis.

All these contagious matters are conceived to be harmless, till they have
been exposed to the air, either openly or through a moist membrane; from
which they are believed to acquire oxygene, and thence to become some kinds
of animal acids. As the preparations of mercury cure venereal ulcers; as a
quarter of a grain of sublimate dissolved in wine, and given thrice a day;
this effect, seems to b