ORGANISM OF YELLOW FEVER 205 
Quite as conclusive as the New Orleans experience has been the result of the 
work on the Isthmus of Panama. This work is also described in some detail 
among the examples of remedial work. 
THE DEATHS OF REED, CARROLL, AND LAZEAR. 
The deaths of Lazear, Reed and Carroll, following the brilliant results of their 
work, are inexpressibly sad. Dr. Lazear was a young man of great ability, 
admirably trained, whose work, as Dr. Reed says, was characterized by “ a manly 
and fearless devotion to duty such as I have never seen equaled.” He “seemed 
absolutely tireless and quite oblivious of self. Filled with an earnest enthusiasm 
for the advancement of his profession and for the cause of science, he let no 
opportunity pass unimproved. Although the evening might find him dis- 
couraged over the difficult problem at hand, with the morning’s return he again 
took up the task, full of eagerness and hope.” His death was due to accidental 
inoculation, by an infected mosquito, in the course of his researches at Havana. 
When the Board resumed its work after his death in November, 1900, and es- 
tablished the experiment station at Quemados, they named it in honor of their 
comrade, Camp Lazear. Dr. Walter Reed, the inspiring genius of the investi- 
gation, died suddenly November 23, 1902, with his health impaired by his 
strenuous labors. He had reaped some of the honors following his monumental 
work, but by no means all. His name will live as that of one of the great bene- 
factors of the human race. Dr. Carroll, although he lived for a few years longer, 
died September 16, 1907. At Havana, in 1900, he suffered the first experi- 
mentally produced attack of yellow fever and it proved a severe one. His early 
death was undoubtedly due to the effect of the disease. He lived just long 
enough to see the substantial results which followed the great work with which he 
had been so prominently connected. Personally, all three were of the highest 
type, and each is mourned by a host of warm friends, as well as by the world 
at large. 
THE SEARCH FOR THE CAUSATIVE ORGANISM. 
The experiments just recorded demonstrate beyond all doubt that the specific 
agent of yellow fever inhabits the blood. A most prolonged microscopic search 
was made, not only by Reed and Carroll, but by many other investigators, with 
fresh and stained preparations of blood, taken at various stages of the disease 
and during early convalescence. But all of this search was negative. Further 
search was made in the bodies of infected mosquitoes dissected fresh, and also by 
means of serial sections of the hardened insect, and no results worthy of men- 
tion were obtained. The attention of Reed and Carroll was soon called by Welch 
to the important observations of Loeffler and Frosch on the etiology of the foot- 
and-mouth disease of cattle. In this disease the lymph, collected from the blebs 
present in the mouth and feet of sick cattle, had been diluted and passed several 
times through a porcelain filter, with the result that this strained and diluted 
lymph injected into calves produced the disease as promptly as with others that 
had been injected with the same quantity of unfiltered lymph. The German 
authors decided that there were two possible explanations of this result: either 
