YELLOW FEVER 



671 



blood from patients, later causing the same insects to feed upon normal 

 susceptible individuals. The first nine experiments were negative. 

 The tenth, of which Carroll was the subject, was successful. Four days 

 after being bitten by the infected insect Carroll became severely ill with 

 an attack of yellow fever, by which 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 deliber- 



(a) . (6) 



FIG. 155. STEGOMYIA FASCIATA. (a) Female. (6) Male. (After Carroll.) 



ately 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 Surg. Jour., 14, 1901; Carroll,. Jour. Am. Med. Assn., 40, 1903; Carrol, " Yello\ 

 Fever" in Mense, " Handbuch der Tropen-Krankheiten," ii. 

 44 



