BIOLOGY AND HUMAN WELFARE 389 



A. Medicine 



Health — the adaptation supreme — is a priceless possession 

 whether it be estimated from the standpoint of the well-being of 

 the individual or in terms of national wealth. Accordingly, medi- 

 cine, in the broadest sense of the word, is without doubt the most 

 important aspect of applied biology. Human anatomy and physi- 

 ology, on which the foundations of medicine rest, are merely special 

 parts of the general sciences of anatomy and physiology of all 

 organisms. In fact the interpretation of human anatomy is impos- 

 sible except in the light of the comparative anatomy of Verte- 

 brates, while human physiology owes its present state of develop- 

 ment to the fundamental principles derived from experimentation 

 on the lower animals. And hope for further advance is chiefly de- 

 pendent upon similar investigations on animals which have been 

 rendered insensible to pain by anesthetics. To mention one ex- 

 ample: experimental surgery practiced on animals has demon- 

 strated the possibility of innumerable operations which no con- 

 scientious surgeon would have ventured to perform for the first 

 time on Man. In the words of Darwin who gave up the sport of 

 hunting on account of his great sympathy with the suffering of 

 animals: "Physiology can make no progress if experiments on liv- 

 ing animals are suppressed, and I have an intimate conviction that 

 to retard the progress of physiology is to commit a crime against 

 humanity." 



1. Microorganisms and Disease 



No one will gainsay that discoveries in preventive and curative 

 medicine rank amongst the most important contributions of sci- 

 entific research to civilization, and nearly all have as their founda- 

 tion studies by generations of biologists. Though Pasteur's first 

 investigations were in chemistry, his subsequent work, which 

 pointed out the way of preventing and eradicating diseases due to 

 microorganisms, followed naturally from his discovery that the 

 souring of wine and milk is the result of the activities of organisms 

 from the air which induce chemical changes. Injure the skin of a 

 grape, and organisms from the atmosphere enter and fermentation 

 begins. Exclude air or sterilize it, and fermentation is prevented. 

 Lister immediately saw the importance of this for surgery, and 

 modern aseptic surgery — one of the greatest blessings of man- 

 kind — was born. (Figs. 152, 278.) 



