Discovery of 

 the Germ. 



Koch's Circuit 

 Not Proven. 



An Air-borne 

 Disease. 



BACTERIOLOGY IN A NUTSHELL. 



Smallpox. The micro-organism which 

 causes smallpox was reported as discovered by 

 Dr. Wm. T. Councilman, of Harvard College, 

 Boston, Mass., in the early spring of 1904. 

 He made known his discovery during the 

 course of a lecture given in that city on "The 

 Aetiology of Smallpox." He described the 

 germ of smallpox as a "protozoon," represent- 

 ing the very lowest order of animal life and 

 therefore quite different from the vegetable 

 micro-organisms common to the majority of 

 communicable diseases. Dr. Councilman is 

 said to have proven that his germ will pro- 

 duce smallpox by his experiments on rabbits 

 and monkeys, but as it is not produced by cul- 

 tures Koch's circuit is not traced. The small- 

 pox infection is general. It invades the skin, 

 the conjunctiva, the mouth, the oesophageal 

 tract, the rectum, and the blood. 



Smallpox is one of the air-borne diseases and 

 enters the system through the respiratory tract 

 and may also be introduced through the skin. 

 The disease is so readily communicable that all 

 discharges must at once be disinfected or 

 burned. The chief factors in the spread of the 

 disease are the secretions from the nose and 

 throat and the desquamating skin, all of which 

 •contain the poison. Flies which alight on 

 patients spread the disease. Patients must be 

 protected by screens about their beds. Great 

 104 



