ii8 SCIENCE REMAKING THE WORLD 



to the scientific world, numerous observers began to ex- 

 periment in order to learn how the tubercle bacillus 

 entered the body. There were those who believed that 

 it entered the body through the respiratory passages; 

 others who thought that it entered the body through the 



TUBERCULOSIS DEATH RATE OF U 5 REGISTRATION AREA 



PULMONARY AND OTHtR FORMS 



300 TO 1921 irvc 



ku.rw.KJ 10. >4 



digestive tract; others by way of the skin; and a few 

 who still believed that the disease was hereditary and 

 that the tubercle bacilli were transmitted directly from 

 mother to infant. The researches of Cornet and others 

 showed that in experimenting upon animals tuberculosis 

 could readily be induced by permitting them to inhale 

 moist air which was impregnated with tubercle bacilli. 

 For a considerable time nearly all the methods for the 



