120 POPULAR SCIENCE MONTHLY. 



clews to clearer methods of diagnosis and more rational lines of 

 treatment." Recognizing the gi-eat gains that have accrued to 

 medicine from the marvelous development of pathological inves- 

 tigation and from anatomy and histology, he added : " If, however, a 

 small fraction of the time and energy given to these branches of 

 medicine had been devoted to the simultaneous study and investiga- 

 tion of the chemical processes of the body in health and disease, I 

 am sure equally important results would have been obtained, and, as 

 a final outcome, a far more satisfactory explanation of many phe- 

 nomena for which anatomy, histology, and pathology have thus far 

 given only incomplete or unsatisfactory explanations. It is from a 

 judicious combination of the results obtainable by different lines of 

 inquiry that the broadest and most definite, as well as the most accu- 

 rate, deductions are to be drawn. In estimating the value of the 

 various aspects of the study, it is shown that our knowledge of the 

 composition of the tissues, organs, and fluids of the organism is de- 

 rived entirely from chemical study and investigation. This is 

 plainly self-evident; but when we consider how far-reaching are the 

 facts thus obtained in promoting our understanding of the laws of 

 growth of the human body, of the relationships of the various physio- 

 logically active and inactive tissues, of their development, of the 

 character and extent of their activity, and of all the variations inci- 

 dent to pathological conditions, we see at once the great importance 

 of this knowledge in aiding us to a rightful interpretation of physio- 

 logical laws. The great progress made of late years in our knowledge 

 of the various digestive juices of the body, of their mode of action, 

 of the character of the products resulting from the digestion of the 

 various classes of food stuifs, of the conditions favorable and unfa- 

 vorable to ferment action — these and many other things connected 

 with the study of digestion in its broadest sense have all been accom- 

 plished as the results of long-continued and laborious experiments — 

 results that have not only helped to give us broader and clearer ideas 

 of the physiology of digestion, but have made possible much of the 

 advance in the diagnosis and treatment of disorders of the alimentary 

 tract." Then there are the chemical composition of muscle and 

 nerve tissue and the processes going on in them, with their influence 

 on heat production and on proteid and other forms of metabolism; 

 the broad question of nutrition in general, with its bearing on health 

 and disease — "in great part chemical problems, partial solution of 

 which has already afforded results of inestimable value " ; and " the 

 part chemistry has played in bringing about our present understand- 

 ing of the manner in which micro-organisms act in the animal body, 

 with its bearing upon the whole question of infectious diseases, the 

 discovery of the production of distinct chemical poisons by specific 



