SERUM THERAPY 115 



Prevalence Lobar pneumonia is an endemic 

 and general sporadic disease that is common 

 throughout the United States and Canada. It 

 is frequent all over temperate Europe and in 

 the inhabited portions of the South Temperate 

 Zone, such as Australia, parts of South Amer- 

 ica, and in South Africa. Although it is much 

 less frequent in the tropics, it is often seen even 

 there among the inhabitants of the plateau re- 

 gions. The disease exhibits very marked ex- 

 acerbations during certain years. The majority 

 of cases occur between November and June, 

 which is supported by the findings in 34,587 

 collected cases. Accounts of supposed pneu- 

 monia epidemics go back nearly as far as writ- 

 ten history itself. An extensive tabulation has 

 been made by Wells, who gives a list of epidem- 

 ics extending back to 1440. It is supposed by 

 some that the plague of Athens, which destroyed 

 one-fourth of the population, as well as the 

 Black Death which ravaged Europe during the 

 middle of the fourteenth century, were forms of 

 pneumococcus infection. 



In the United States during the census year 

 of 1900, over lO 1 /? per cent of all deaths were due 

 to pneumonia. Reports published in different 



