INTRODUCTION. 



incompatibilities of drugs, then the best way to acquire such knowledge is by personal 

 investigation. 



In Pharmacodynamics, it is impossible for the students, through lack of time, to 

 study many of the drugs experimentally ; so an intensive study may well be made of the 

 more important ones, especially those which produce registerable reactions. In such 

 a study, a graded method is pedagogically superior. Hence the student is directed to 

 first observe the way and manner in which simple tissue reacts to drug influence, for 

 this purpose using the common frog. Next, he studies the reactions to that same drug 

 of one of the mammals, like the cat, or rabbit, or dog. Then, because of sundry diver- 

 gencies between the reactions of the lower animals and the higher, he tests this same 

 drug on a human being his fellow-student gaining thereby also invaluable experience 

 in observational methods. Next, inasmuch as thus far his information has not had that 

 definite application necessary for conclusiveness, he makes further investigation of the 

 Pharmacodynamics of that same drug at the hospital, in an attempt to learn how much 

 and in what manner the toxins of disease may modify the apparent action of drugs. 

 Finally, he checks up his accumulated observations by comparing them with the recorded 

 observation of others, as presented in current literature. Thus the student acquires a 

 training in method and procedure of inestimable value in his future work as a scien- 

 tific physician. 



A. D. BUSH. 



