286 



YELLOW FEVER 



beginning of January, there has not been a single 

 case. Whereas, for the years since 1889, from 1st 

 April to 1 st December, yellow fever caused an 

 average of 410.54 deaths, with a maximum of 1 1 75 

 for 1896, and a minimum of 79 for 1899, it caused 

 in 1 90 1 5 deaths only. In the months of October 

 and November, when the disease has hitherto been 

 exceedingly rife in Havana, there has not been a 

 single case. For the first time in 1 50 years, Havana 

 has been free from yellow fever." 



Thus, in a few years, from experiments on 

 mosquitoes, sparrows, and men, has come the 

 present plan of campaign against malaria, yellow 

 fever, and filariasis ; that is, against Anopheles and 

 Cnlex. He who would know what is being done 

 to check these diseases in Italy, India, China, 

 Africa, and America, must read Major Ross' 

 Malarial Fever, its Cause, Prevention, and Treat- 

 ment (1902), and Mosquito Brigades, and how to 

 organise them (1902). There has been nothing 

 like it since Pasteur died. Far and wide, from 

 Staten Island to Cuba, from Hong Kong to 

 Lagos, the work of keeping down the larvae of 

 Anopheles and Culex is going on. Henceforth we 

 have to reckon not with a nameless something, but 

 with a definite parasite, whose conditions of life are 

 known. Before all things, we must shut off the 

 sources of the infection. For centuries, men had 

 believed in exhalations and miasmata lying all 

 over the land : and, behold, the agents of malaria 

 are in the puddles round a man's house, and the 



