EXTRACT XVII. 



ON COUNTER-IRRITATION, OR ARTIFICIAL METASTASIS. 



THE term counter-irritation is of considerable antiquity, 

 but to whom we are indebted for its origination we have 

 not as yet satisfactorily discovered, nor have we yet very 

 clear ideas of its true nature and therapeutical application 

 to the relief and cure of certain diseased conditions ; 

 nevertheless we think we are warranted in obtruding some 

 of the views of which we have become possessed on the 

 subject on the attention of those interested in such matters, 

 in order that empiricism in its use should become tinctured 

 somewhat more with scientific precision and warranty. 

 What, then, is counter-irritation ? Before answering this 

 question, it seems right to ask, what is irritation ? in order 

 that we should more clearly understand the rationale of 

 counter-irritation. Irritation then, as a scientific term, 

 must be understood as applicable only to a condition of the 

 nervous system, or part of the nervous system, which ends 

 in eliciting or inducing involuntary contraction of muscular 

 fibre in its motor aspect, or disagreeable sensation in its 

 sensory aspect, and as dependent on the existence of an 

 exciting or provocative agent or functional stimulus, which, 

 if intense enough or long enough continued in its applica- 

 tion, may produce disease of a local or even general 

 character. 



Irritation is thus a thing of nervine origin and essence, 

 and, therefore, requiring for its relief or removal an appeal 

 primarily to the nervous system. That the nervous 

 system by direct or reflex agency can transfer the product 

 of irritation, be it sensory or motor, from the actual seat 



