MOSQUITOES 81 



Carroll, Jesse W. Lazear, and A. Agramonte, was sent 

 to Cuba to investigate the whole question. 



In a field near Quemados, Cuba, this commission of 

 surgeons erected a small wooden building tightly ceiled 

 and with the windows and doors closely screened so that 

 no mosquitoes could enter. In this house, during a total 

 of sixty-three days, seven non-immune men were kept. 

 These men slept in beds furnished with the unwashed 

 pillow-slips, sheets, and blankets that had previously 

 been used on the beds of genuine yellow fever patients in 

 Havana and elsewhere. This bedding was actually 

 stained with the excretions of the fever patients. Neither 

 during that time nor subsequently did one of these seven 

 men develop a case of yellow fever. This indicated to 

 the surgeons, beyond much question, that yellow fever 

 is not carried in clothing, as had always been held. This 

 experiment concluded the first phase of the work. 



Another house was built in this same field and divided 

 by wire screen from floor to ceiling, into two rooms. 

 The doors and windows of each room were closely screened 

 with fine wire netting so that no mosquitoes could 

 enter. All bedding and material carried into the rooms 

 were disinfected by steam, which precluded any possi- 

 bility of the yellow fever germ being present in the 

 bedding or clothing. 



In one of the rooms, mosquitoes of a certain kind that 

 had previously bitten patients sick with yellow fever were 

 placed. In the other room none were allowed. Non- 

 immune men were placed in both rooms. Of those in 

 the room containing no mosquitoes, not one had yellow 

 fever. Of those in the other room that were bitten by 

 the infected mosquitoes, six out of seven developed cases 



