SMALLPOX 163 



The pyogenic bacteria are nearly always found in 

 the pustules of smallpox, and it is said that when the 

 secondary infection is due to streptococci, the attack 

 is nearly always fatal. 



Smallpox is common to all ages, but by far the 

 greatest number of deaths occur among young per- 

 sons. The colored races are more susceptible to 

 smallpox than the whites. 



Historical medical records relate the existence of 

 smallpox in Central Asia during the tenth century, 

 in Europe during the tweKth century, and that it 

 was introduced into North America by the Spaniards 

 in the sixteenth century. 



Transmission. — The modes of infection in small- 

 pox, like the niicroorganism which causes it, are 

 still questions to be answered; for years it was 

 thought the transmission was through the air, 

 and of course by contact, but the air-borne theory 

 is now questioned by some of the best authori- 

 ties, and no new light has been thrown on the 

 subject. 



Prophylaxis. — For the prevention of smallpox 

 vaccination is by far the most important measure 

 to be employed ; without vaccination, isolation and 

 disinfection can be of limited effect. ' 



Prior to Jenner's discovery of the value of the virus 



