2 EXPERIMENTAL RESEARCHES 



Besides, pharmacology has but just emerged 

 from the stage of pure observation and descrip- 

 tion. One was content formerly with describing 

 the physiological effects and the secondary action 

 of substances which act pharmaco-dynamically, 

 as well as the morphological changes which 

 they bring about in the organs and tissues 

 of the body. Observations made on an em- 

 pirical basis such as this, formed a mass of 

 most needful knowledge, and even to-day we 

 have no hesitation in admitting that the study 

 of the symptomatology of drugs is still a work 

 of absolute necessity and must yield very fruitful 

 results. Indeed, by such means we learn not 

 only how to make use of known drugs in a 

 purposeful manner, but also how to avoid their 

 undesired secondary actions. But merely to 

 increase the contents of our pharmacopoeia is 

 not to add to our resources in this desirable 

 direction : for such an increase may depend on 

 accidents, which, in their turn, may be the 

 outcome of empiricism. It is to the great 

 influence which chemistry exerts on medical 

 science that we owe the change in this state of 

 affairs ; for it is especially necessary to have 

 clear ideas of the relations between chemical 

 constitution and pharmacological action. 



