Campaign and Results 301 



Aedes calopus hovered in the vicinity, and there 

 was no house near. 



No case of yellow fever had occurred at Paraiso. 

 "What was the source of infection? The histories 

 of all cases that might be the source of the infection 

 of the last case were reconsidered, and in point of 

 time occurrence only one case seemed important. 

 It was that of a peddler in the city of Panama, ill 

 with yellow fever in the hospital. His history 

 showed that he had not been to Paraiso, and on 

 being questioned, he confirmed the statement. 

 His friends corroborated it. The Paraiso case 

 was still a puzzle. The patient's quarters at 

 Paraiso, and adjacent houses, were fumigated to 

 prevent secondary cases, and then the following 

 action was taken. It was assumed that the 

 possibility of infection at the pay car was too 

 remote for serious consideration, and that some 

 unknown infected person must have been to 

 Paraiso before the engineer became sick. We 

 visited every house, seeking for information, and 

 received much confusing testimony. A second 

 trip was made to determine if any stranger had 

 been there to sell anything. We found that a man 

 had been there seUing trinkets similar to those in the 

 above-mentioned peddler's box. It was finally 

 proven that the Panama peddler had not only 



