memorable report proclaiming the new dogma. The work then 

 described was so thorough and the results so clearly established as 

 leave no doubt in the minds of his hearers as to the truth of his c< 

 elusions. Considering the number of able men who had been stu( 

 ing the subject, it is remarkable that a period of nearly twenty ye: 

 should have elapsed before Finlay's ideas were seriously considei 

 and finally accepted. It is still more remarkable when we consic 

 that since the early part of the nineteenth century various observ 

 had indicated the mosquito as in some way related to the disei 

 under consideration. There is no doubt but that the interesting wc 

 of Dr. Henry R. Carter, of the Public Health and Marine- Hospi 

 Service, in establishing, in 1898, the " extrinsic " period of incubati 

 of yellow fever — that is, the interval between the infecting and s 

 ondary cases — gave renewed impetus to the study of the mosquito 

 a factor in yellow fever and indirectly brought about the confirn 

 tion of the truth of the hypothesis of Doctor Finlay. 



PBDTOIPLES OF PEOPHYLAXIS. 



The prophylaxis of yellow fever, which up to a few years ago m 

 founded on ideas so uncertain and insecure, is to-day firmly bas 

 on the discovery of the transmitting agent of the disease. This ag< 

 can be destroyed and may be prevented from becoming itself inoc 

 lated and, if inoculated, from transmitting the disease to the w< 



In the abstract the measures necessary to accomplish this are pi 

 fectly feasible. No extraordinary means or intelligence is requir 

 to make them effective; only a careful attention to details. But 

 practice, when the peculiarities of human nature, the rights of t 

 individual as guaranteed by the law, and the ignorance of the peoj 

 have to be taken into account, the problem becomes both difficult a 

 onerous. 



The subject of the prophylaxis of yellow fever has been thorougl 

 thrashed out during the last few years, and as the matter is so simj 

 in itself there is but little that may be added to what has alrea 

 been said. Within the time stated the writer has been connect 

 with the two epidemics which have occurred in the United States- 

 Laredo, Tex., in 1903, and at New Orleans and Vicksburg in the ge 

 eral epidemic of 1905 — and has carried out with success the princip 

 of prophylaxis which will be referred to in this article. It is n 

 however, the purpose to enter herein into the minutiae of the mel 

 ods of prophylaxis, but rather to invite attention to some of t 

 difficulties to be encountered and to suggest some of the mea 

 whereby, in the opinion of the writer, the obstacles found in t 

 practical application of the principles involved may be lessened 

 eliminated. 



