n
natural, and indigestion and heartburn succeed, nothing so certainly
removes these symptoms as the stimulus of a blister on the back. The
coldness of the extremities, as of the nose, ears, or fingers, are hence
the best indication for the successful application of blisters.

5. Decrease the stimulus for a time. By lessening the quantity of heat for
a minute or two by going into the cold bath, a great accumulation of
sensorial power is produced; for not only the minute vessels of the whole
external skin for a time become inactive, as appears by their paleness; but
the minute vessels of the lungs lose much of their activity also by concert
with those of the skin, as appears from the difficulty of breathing at
first going into cold water. On emerging from the bath the sensorial power
is thrown into great exertion by the stimulus of the common degree of the
warmth of the atmosphere, and a great production of animal heat is the
consequence. The longer a person continues in the cold bath the greater
must be the present inertion of a great part of the system, and in
consequence a greater accumulation of sensorial power. Whence M. Pome
recommends some melancholy patients to be kept from two to six hours in
spring-water, and in baths still colder.

6. Decrease the stimulus for a time below the natural, and then increase it
above natural. The effect of this process, improperly used, is seen in
giving much food, or applying much warmth, to those who have been
previously exposed to great hunger, or to great cold. The accumulated
sensorial power is thrown into so violent exertion, that inflammations and
mortifications supervene, and death closes the catastrophe. In many
diseases this method is the most successful; hence the bark in agues
produces more certain effect after the previous exhibition of emetics. In
diseases attended with violent pain, opium has double the effect, if
venesection and a cathartic have been previously used. On this seems to
have been founded the successful practice of Sydenham, who used venesection
and a cathartic in chlorosis before the exhibition of the bark, steel, and
opiates.

7. Prevent any unnecessary expenditure of sensorial power. Hence in fevers
with debility, a decumbent posture is preferred, with silence, little
light, and such a quantity of heat as may prevent any chill sensation, or
any coldness of the extremities. The pulse of patients in fevers with
debility increases in frequency above t