1 6 MALARIA 



have been advanced against the theory. Drs. Sambon 

 and Low, Mr. Terzi, their servants and visitors, 

 lived for the three most malarial months of 1900 in 

 one of the most malarial localities of the Roman Cam- 

 pagna, Ostia, in a hut from which mosquitoes were 

 excluded by a simple arrangement of wire gauze on 

 the doors and windows. They moved freely about 

 in the neighborhood during the day, exposed them- 

 selves in all weathers, drank the water of the place, 

 often did manual work, and beyond retiring from 

 sunset to sunrise to their mosquito-protected hut 

 observed no precautions whatever against malaria. 

 They took no quinine. Although their neighbors, 

 the Italian peasants, were each and all of them attacked 

 with malaria, the dwellers in the mosquito-proof hut 

 enjoyed absolute immunity from the disease. Whilst 

 this experiment was in progress mosquitoes fed in 

 Rome on patients suffering from tertian malaria were 

 forwarded in suitable cages to the London School of 

 Tropical Medicine, and on their arrival were set to 

 bite my son, the late Dr. P. Thurburn Manson, and 

 Mr. George Warren. Shortly afterwards both of 

 these gentlemen, neither of whom had been abroad or 

 otherwise exposed to malarial influences, developed 

 characteristic malarial fever, and malarial parasites 

 were found in abundance in their blood, both at that 

 time and on the occurrence of the several relapses of 

 malarial fever from which they subsequently suffered. 

 'The mosquito-malaria theory has now, therefore, 



