27G ILLINOIS STATE ACADEMY OF SCIENCE 



previous to this time. Often the symptoms are very ob- 

 scure, and it is possible many more cases may occur than 

 are recognized. 



Eabies is spread usually by our good friend, the dog, 

 though all other animals are susceptible and if infected 

 are sources of danger. The disease for centuries was the 

 dread of all peoples, in some communities the unfortunate 

 person bitten by an infuriated animal being put to death 

 immediately. Xot till fifty years ago did Pasteur discov- 

 er a preventative which has greatly reduced the mortal- 

 ity. In 1922. 50 deaths were reported in the United 

 States. At the present time there amounts to what is 

 almost an epidemic of rabies among dogs in the southern 

 part of Illinois. 



Of all useless animals on earth, the rat is the most de- 

 testable. As a marauder he is bad enough, as a murderer 

 he excels. Keference has already been made to bubonic 

 plague, which has swept the world in three great pandem- 

 ics. The first authentic epidemic originated in 542 A. D. 

 in Pelusium, Egypt. It spread by trade routes over 

 the then known world, till at its height the morality was 

 5,000 persons a day and rose to 10,000 persons some days. 

 According to Procopius, a witness of the epidemic, "It 

 spared neither island nor cave nor mountain top where 

 man dwelt — . Many houses were left empty and it came 

 to pass that many for want of relatives and servants were 

 left unburied for several days. At that time it was hard 

 to find any one at business in Byzantium. Most people 

 who met in the streets were bearing a corpse. All busi- 

 ness had ceased, all craftsmen had deserted their crafts." 

 The second epidemic, known in history as the Black 

 Death, originated in Mesopotamia about the middle of 

 the eleventh century. Again the disease spread by trade 

 routes over the entire known world, carrying off 25,000,- 

 000 peop ] e. or one-fourth the population of Europe. The 

 third epidemic had its origin in China in 1871, coming to 

 the ports of Europe and America. Due to advancement 

 of the sanitary sciences and their strict application in 

 war upon rats and fleas, the world epidemic never 

 reached beyond isolated cases at seaports in Europe and 

 America. The disease is of especial importance to Illi- 



