CHAPTER XXX 



BACTERINS, SERUMS, VACCINES AND ANTITOXINS 

 HISTORICAL 



The present trend of medicine is toward prophylaxis. It is 

 tending toward the old Chinese custom which gave the physician a 

 fee when the patient was well but as soon as he fell sick the pay- 

 ments stopped- The doctor was paid for keeping his patients in 

 good bealtib. Biological products in the form of vaccines, serums and 

 antitoxins have been and are widely used as prophylactic as well as 

 therapeutic agents. The history of the application of these far 

 antedates modem medicine. Hippocrates taught that that which 

 could produce disease was also capable of curing it, a theory which 

 underlies modern homeopathic niedicine. Pliny, the Elder, recom- 

 mended the livers of mad dogs as a cure for hydrophobia. In Asia 

 and other Oriental countries the custom of exposing people to mild 

 forms of smallpox in order to render them immune was practised 

 for many centuries before the discovery of smallpox vaccination. 



It remained for Edward Jenner in 1793 to demonstrate in a 

 scientific manner that cow pox, conveyed to man a definite immunity 

 against small pox. This discovery was based on the observation 

 that milk maids who had contracted cow pox in the natural pursuance 

 of their occupation were thereafter immune to small pox. 



Very little progress along these lines was made for eighty years 

 or until modern bacteriology began its development. The master 

 scientific mind of Pasteur thought out and developed several of the 

 most important discoveries in the field of vaccination that have ever 

 been made. The first was in relation to fowl cholera. Many of 

 the chickens around Paris were dying from a virulent infection and 

 Pasteur isolated the causative organism, Bad. cholerw gallinarum. 

 It was found by accident that cultures of this organism could be 

 attenuated by cultivation so that they were not capable of producing 

 the disease. It was further noted that fowls that had been injected 

 with this non-virulent culture did not succumb when later they were 

 inoculated with a dose of a virulent strain of these bacteria. This 

 furnished Pasteur with the key to the knowledge of active immuniza- 

 tion and he had the genius to apply his discovery to the prevention of 

 disease. To this great man of science we owe our present system of 

 immunization against anthrax and rabies. The original methods 

 Pasteur employed in the prevention of these two scourges of man and 



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