68 The Story of the Bacteria 



fection be more susceptible than is usual to 

 the ravages of the invader and thus be the 

 victim of a graver form of the disease. 



Infectious diseases of the type of small-pox, 

 measles, and scarlatina, whose infective agents 

 are easily transmitted, are called contagious. 

 When it is said of an infective disease that 

 it is more or less readily communicable, it is 

 really meant that the infective agent is 

 communicable, not the disease. For disease 

 is always a process of the body and not a 

 thing, and so cannot be transmitted. 



The elder folk were wont to think of diseases 

 as some sort of demons or evil spirits which 

 attacked the body or took possession of it, 

 and tried to banish these by rattles, drums, 

 or songs and incantations, as some of our 

 North American Indians do to-day. Though 

 we know that disease is not a thing but a 

 disturbance of the body processes, we still 

 speak of disease as attacking the body. We 

 say "the man was attacked by a severe 

 dyspepsia after eating hot plum pudding. " 

 But it was really not the dyspepsia, it was the 

 plum pudding which attacked the man. 



