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.