e same time with a hot and dry skin.

The disturbed actions of this circle of the associate motions of the
secerning system, when the sensorial power of sensation is added to that of
irritation, frequently produces inflammation, which consists in the
secretion of new fluids or new vessels. Nevertheless, if these disturbed
actions be of the torpid kind, the pain, which attends them, is seldom
productive of inflammation, as in hemicrania; but is liable to excite
voluntary actions, and thus to expend much sensorial power, as in the
shuddering in cold fits of fever, or in convulsions; or lastly the pain
itself, which attends torpid actions, is liable to expend or exhaust much
sensorial power without producing any increased actions; whence the low
pulse, and cold extremities, which usually attend hemicrania; and hence
when inert, or inactive sensation attends one link of associated action,
the succeeding link is generally rendered torpid, as a coldness of the
cheek attends tooth-ach.

5. A fifth important circle of irritative motions is that of the
sanguiferous system, in which the capillary vessels are to be included,
which unite the arterial and venous systems, both pulmonary and aortal. The
disturbed action of this system of the heart and arteries, and capillaries,
constitute simple fever; to which may be added, that the secerning and
absorbent vessels appending to the capillaries, and the bibulous mouths of
the veins, are in some measure at the same time generally affected.

6. Now, though the links of each of these circles of irritative motions are
more strictly associated together, yet are they in greater or less degree
associated or catenated with each other by direct or reverse sympathy. Thus
the sickness, or inverted irritative motions of the stomach, are associated
or catenated with the disturbed irritative ideas, or sensual motions, in
vertigo; as in sea-sickness. This sickness of the stomach is also
associated or catenated with the torpor of the heart and arteries by direct
sympathy, and with the capillaries and absorbents by reverse sympathy; and
are thus all of them liable occasionally to be disturbed, when one of them
is diseased; and constitute the great variety of the kinds or symptoms of
fevers.

VII. _Alternation of the cold and hot Fits._

1. When any cause occurs, which diminishes to a certain degree the supply
of sensorial power in respect to the whole system; as suppose a temporary
inexertion of th