876 PATHOGENIC MICROORGANISMS 



his life was endangered, and from the effects of which he died several 

 years later. 



On the 13th of September, Lazear, while working in the yellow- 

 fever wards, noticed that a stegomyia had settled upon his hand, 

 and deliberately allowed the insect to drink its fill. Five days later 

 he became ill with yellow fever and died after a violent and short 

 illness. 



With these experiences as a working basis, the commission now 

 decided upon a more systematic and thoroughly controlled plan of 

 experimentation. 



In November of the same year, 1900, an experiment station, 

 "Camp Lazear," was established in the neighborhood of Havana, 

 about a mile from the town of Quemados. The camp was surrounded 

 by the strictest quarantine. Volunteers from the army of occupation 

 were called for, and twelve individuals were selected for the camp, 

 three immunes and nine non-immunes. Two of the latter were 

 physicians. The immunes and the members of the commission only 

 were allowed to go in and out. All non-immunes who left the 

 camp were prohibited from re-entering and their places taken by 

 other non-immune volunteers. During December, five of the non- 

 immune inmates were successfully inoculated with yellow fever by 

 means of infected mosquitoes. During January and February five 

 further successful experiments were made. Clinical observations 

 were made by experienced native physicians, Carlos Finlay among 

 them, and the patients, as soon as they were unquestionably ill 

 with yellow fever, were removed to a yellow-fever hospital. This 

 was done to prevent the possibility of the disease spreading within 

 the camp itself. The mosquitoes used for the experiments were 

 all cultivated from the larva and kept at a temperature of about 

 26.5 C. 



A further important experiment was now made. A small house 

 was erected and fitted with absolutely mosquito-proof windows and 

 doors. The interior was divided by wire mosquito netting into two 

 spaces. Within one of these spaces fifteen infected mosquitoes were 

 liberated. Seven of these had fed upon yellow-fever patients four 

 days previously; four, eight days previously; three, twelve days 

 previously ; and one, twenty-four hours previously. A non-immune 

 person then entered this room and remained there about thirty 

 minutes, allowing lumself to be bitten by seven mosquitoes. Twice 

 after this the same person entered the room, remaining in it alto- 



