STUDY OF PHARMACOLOGY. 223 



more than a field strewn with slain or crowded with heaps of 

 wounded is a battle. The disease was the alteration in the 

 nervous and vascular systems, and in the nutrition of tissues, 

 which we call the inflammatory process, and which produced 

 the abscess and degeneration, and the disturbance of the same 

 systems, to which these lesions in their turn give rise ; just as 

 an army may not only lose the battle for want of the assistance 

 which its slain and wounded would have given, but its retreat 

 may be embarrassed by their presence. 



The insufficiency of present modes of treatment, and the 

 urgent necessity which exists for an accurate knowledge of 

 pathology and pharmacology, are shown by the manner in which 

 any new remedy is seized upon and applied in all sorts of cases, 

 even in those where a knowledge of the morbid processes going 

 on, and of the action of the remedy itself would at once have 

 indicated that harm, and not benefit, must ensue from its appli- 

 cation. It is unnecessary to discuss here the manner in which 

 pathology must be studied in order that an accurate knowledge 

 of it may be obtained : I may merely indicate as examples the 

 works of Cohnheim, Brown-Sequard, Sanderson, Stockvis, 

 Strieker, and many others. 



Pharmacology. — In studying pharmacology, our first object is 

 to find out on what structures a remedy acts. For this purpose, 

 it is of no use to give it to a man either sick or well. We may 

 do so in order to find out what general symptoms it produces ; 

 and from these symptoms we may guess at the structures 

 affected ; but, in order to convert our hypothesis into certainty, 

 we must have recourse to an experiment which may be of two 

 kinds, Firstly, we may apply the drug to those structures or 

 organs which we suppose to be affected by it, and to them alone, 

 and see whether the general result is the same. This we 

 generally do either by immersing them in a solution of it, or by 

 causing blood containing it to circulate througli them. 



Secondly, we may prevent the drug from reaching these 

 tissues or organs while it is applied to all other parts of the 

 body, and observe whether the effect is absent. For this pur- 

 pose, wo cut off from one or other p.irts of the body the supply 

 of blood which carries the drug a!o!:g with it, or we may so 



