BIOLOGY IN HUMAN AFFAIRS 



In such work it is often necessary to inoculate animals 

 with the germs of human disease, or to practice vivisection 

 upon them, as the only method of understanding what 

 goes on in the human body; and it seems incredible that 

 any one should wish to obstruct this very necessary and 

 remarkably successful form of investigation. Yet it is 

 true that the anti-vivisectionists, obsessed by a senti- 

 mentally inverted humanitarianism, have sometimes lost 

 sight of human welfare in their concern for what they 

 suppose to be the sufferings of laboratory animals. It is 

 becoming generally known, however, that investigators 

 customarily use anaesthetics and otherwise treat their 

 subjects with due care; and so, with the spread of popular 

 knowledge, the extreme opponents of vivisection now 

 appear to be losing the influence that not long ago threat- 

 ened to retard the progress of medical science. 



The diseases that are specifically zoological in nature 

 constitute a forbidding menace to human welfare, some of 

 the more important of them being syphilis, yellow fever, 

 African sleeping sickness, dysentery, malaria, and hook- 

 worm disease. Each of these is produced by a specific form 

 of animal life (except dysentery, which is produced by 

 several different organisms), living as a parasite in the 

 human body where it multiplies and gives off poisonous 

 matter. The various effects of these animals and their 

 waste materials constitute the symptoms of the diseases 

 for which they are responsible. Healthy individuals be- 

 come infected by a transfer of the living parasites from a 

 person afflicted with the disease, sometimes directly, 

 by contact, as in syphilis, sometimes through a more or 

 less complicated series of intermediate circumstances, as 

 in malaria and hookworm disease. All of the diseases just 

 mentioned are destructive to a degree which is not com- 

 monly realized. For example, Chandler^ states that "of all 



'Chandler, A. C, "Animal Parasites and Human Disease," 3d ed., p. 147, 

 John Wiley & Sons, Inc., New York, 1926. 



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