to give a list of these agents.


COUNTER-IRRITANTS.


_Counter-irritants_ are substances which produce irritation of the part
to which they are applied, varying in degree from a slight redness to a
blister or pustule. They are applied to the surface with a view of
producing an irritation to relieve irritation or inflammation in some
other or deeper seated part. They are a class of agents which we very
seldom employ, and, hence, we shall notice only a couple of the most
simple.

MUSTARD (_Sinapis_). The flour of mustard, which is best adapted for
domestic use, is employed in the form of a paste spread on cloth. It
takes effect in a few moments; the length of time it remains in contact
with the skin and the strength of the mustard determine the effect
produced.

HORSE-RADISH (_Cochlearia Armoracia_). The leaves are the parts used.
Let them wilt and bind them on the part affected. They act nearly as
energetically as mustard.


DIAPHORETICS.


_Diaphoretics_ are medicines which increase perspiration. Those which
occasion profuse sweating are termed _Sudorifics_. The two terms