74 INFECTION AND IMMUNITY 



at least chills and fever. On the other hand, the 

 debility resulting from an attack seems to constitute 

 a predisposition to subsequent attacks. 



As showing the liability to two or more attacks 

 from certain infectious diseases, I give below a table 

 compiled from the literature, as given in medical 

 journals, which was published several years ago 

 (Maiselis). 



Second Third Fourth 



attacks. attacks. attacks. 



Smallpox 505 9 o 



Scarlet fever 29 4 o 



Measles 36 i o 



Typhoid fever 202 5 i 



Cholera 29 3 2 



These figures support the view generally enter- 

 tained by physicians, that second attacks of measles 

 are comparatively rare, while second attacks of small- 

 pox are not infrequently observed. Considering the 

 large number of cases of typhoid fever which occur 

 annually in all parts of Europe and America, the 

 number of second attacks reported is comparatively 

 small, and in this disease it may be stated that, as in 

 smallpox and scarlet fever, a single attack usually 

 protects during life from subsequent attacks. 



The second attacks of cholera recorded are not 

 numerous, but an investigation made in the countries 

 where this disease prevails annually, or frequently, 

 would probably show that two or more attacks of the 



