41 



winter, four months after the last previous ease had ocurred on that vessel 

 (the preceding November), the facts can be readily accounted for by the 

 hibernation of mosquitoes which had bitten the former yellow fever 

 patients, and, which, upon finding themselves again within tropical 

 temperatures, recovered from their lethargic condition and bit two of the 

 new men of the crew. 



Supported by the above reasons, I decided to submit my theory to an 

 experimental test, and, after obtaining the necessary authorization, I 

 proceeded in the following manner. 



On the 30th of last June, I took to the Quinta de Garcini a mosquito 

 which had been caught before being allowed to sting, and there made it 

 bite and fill itself with blood from the arm of a patient, Camilo Anca, who 

 was in the fifth day of a well characterized attack of yellow fever of which 

 he died two days later. I then picked out F. B., one of twenty healthy non- 

 immunes who have continued until now under my observation, and made 

 the same mosquito bite him. Bearing in mind that the incubation of 

 yellow fever, in cases which allow its limits to be reckoned, varies between 

 one and fifteen days, I ordered the man to be kept under observation. On 

 the 9th of July, F. B. began to feel out of sorts, and on the 14th he was 

 admitted in the Military Hospital with a mild attack of yellow fever 

 perfectly charaterized by the usual yellowness, and albumin in the urine 

 which persisted from the third till the ninth day. 



On the 16th of July, I applied a mosquito at the same Quinta de 

 Garcini, to a patient, Domingo Rodriguez, in the third or fourth day of 

 yellow fever; on the 20th, I allowed the same mosquito to bite me and, 

 finally, on the 22 I made it bite A. L. C, another of the 20 men who are 

 under observation. Five days later, this man was admitted at the Hospital 

 with fever, severe headache, pain in the loins and injected eyes ; these 

 symptoms lasted three days, after which the patient became convalescents 

 without having presented any yellowness nor albuminuria. His ease was, 

 however, diagnosed as ' ' abortive yellow fever ' ' by the physician in charge. 



The 29th of July, I made a mosquito bite D. L. R. who was going 

 through a severe attack of yellow fever at Quinta de Garcini, being then 

 in its third day. On the 31st, I made the same mosquito bite D. L. F., 

 another of my 20 men under observation. On the 5th of August, at 2 a. m.. 

 he was attacked with symptoms of mild yellow fever; he subsequently 

 showed some yellowness but I do not think that he developed any 

 albuminuria ; his case was, nevertheless, diagnosed '^abortive yellow fever. ' ' 



Finally, on the 31st of July, I applied another mosquito to the same 

 patient, D. L. R. at Quinta Garcini, his attack having then reached its fifth 

 day and proving fatal on the following one. On the 2d of August I applied 

 this mosquito to D. G. B., another of my twenty non-immuues. Till the 



