CHEMISTRY IiV ITS RELATIONS TO MEDICINE. 223 



Having thus touched upon the general subject of the relations of 

 chemistry to materia medica and to hygiene, it remains for me to con- 

 sider briefly the relations between chemistry and medicine in a deeper 

 and broader sense. We can not at the present day, like our prede- 

 cessors, regard medicine as a branch of chemistry. There are many 

 kinds of action, not chemical, which must be studied and understood 

 by the physician. Still, undoubtedly many of the physiological pro- 

 cesses are essentially of a chemical nature, and there are many patho- 

 logical phenomena which are also chemical. The complex organism 

 which is the physician's field of work employs a variety of forces, 

 prominent among which is the chemical force. It would be a trite 

 remark to say that the physician can not possibly have a complete com- 

 prehension of what is going on within the body without a fair knowl- 

 edge of chemistry. Yet I fear this fact is not always fully realized, 

 nor indeed generally, if we are to take as evidence the practice of most 

 medical schools. 



Writing a quarter of a century ago, Liebig used these words, which 

 I can not do better than to repeat : " Physiological and chemical re- 

 searches in the field of medicine are only in their infancy, but scarcely 

 begun ; they have furnished the conviction that the processes in the 

 living body rest upon natural laws, and every day brings discoveries, 

 which prove that these laws can be investigated. It is true that in 

 ages gone by there were excellent physicians who knew nothing of 

 anatomy, and that for centuries diseases have been cured, the nature 

 of which was not understood, just as to-day the nature of 'fever' and 

 ' inflammation ' is not known ; but there is not the slightest foundation 

 for the conclusion that an exact insight into these processes is impossi- 

 ble." And again he says : " Without correct ideas in regard to force, 

 cause, action ; without a practical insight into the nature of natural 

 phenomena ; without a thorough physiological aud chemical training, 

 it is no wonder that otherwise sensible men defend the most nonsensi- 

 cal views." 



These words of Liebig are just as forcible to-day as the day they 

 were written, and just as applicable. 



The special value of a training in chemistry for a physician does 

 not necessarily depend upon the fact that he learns a host of useful 

 things, that he learns how to analyze substances, etc. To be sure, these 

 acquisitions are valuable to him. But, if chemistry is to do for him 

 what it can do, he must work so long and so conscientiously in its 

 field as to enable him to acquire the " chemical sense." He must learn 

 to think in the language of chemistry. He must reason as chemists 

 reason not as deeply, of course, but in the same general way. Then 

 chemistry will be to him a constant aid, whose presence he will feel 

 whenever he is brought face to face with life, either in its normal or 

 its abnormal forms. 



But, even if he did not retain a single chemical fact, the training 



