THE METHODS OF SPEEAD OF INFECTION 105 



Anthrax. — Conveyed either by inspiration from infected 

 hides or by inoculation through traumatic injury. Classes 

 1 and 3. 



Cholera. — Conveyed only by swallowing the specific organ- 

 ism in food or dust. Class 2. 



Diphtheria. — Conveyed in food or dust containing the 

 organism coming into contact with a mucous membrane. 

 Class 3. 



Erysipelas. — Infection usually through a wounded or 

 damaged surface of skin or mucous surface. Class 3. 



Influenza. — Probably Class 1. 



Glanders. — Class 3. 



Gonorrhoea. — Class 3. 



Leprosy. — The method of conveyance is unknown. Class 

 4, and possibly Class 2. 



Malaria. — Class 4. 



Measles. — Class 4. 



Pneumonia. — Classes 1 and 4. The micrococcus of Stern- 

 berg is probably very widely distributed in an attenuated 

 condition, in which it has little virulence. 



Rabies. — Conveyed by inoculation. Class 3. 



Relapsing Fever. — Class 4. 



Scarlet Fever. — Classes 2 and 4. 



Small-pox. — Conveyed aerially to great distances. Class 4. 



Syphilis. — Classes 3 and 4. 



Tetanus. — Class 3. 



Typhoid.— Class 2. 



Tubercle. — Classes 1, 2, and 3, the first being most 

 common. The second probably occurs chiefly in young 

 children ; in the case of the third, inoculations {i.e., post- 

 mortem wounds) usually remain as local lesions only. 



Whooping-cough. — Class 4. 



Yellow Fever. — Class 4. 



With regard to diseases generally, the general measures 



