RESEARCHES IN BRAZIL 245 
perimental work. It is true that Dr. Lazear died of yellow fever during the 
course of the investigation, but the bite by which he was inoculated was not 
given in the course of the experimental work. Dr. Reed himself died three years 
later; his death having been indirectly the result of his arduous labors on the 
Board. Dr. Carroll died still four years later and his death, too, was probably 
caused indirectly by the yellow fever which he contracted in 1900 in the course 
of the experiments. Kissinger is reported, at the time of the present writing, 
to be living in the State of Washington, and in very enfeebled health. Efforts 
are being made to secure for him a well-deserved pension. 
After the publication of the first note by the Board some incredulity was ex- 
pressed, and the British Medical Journal stated of the experiments, “ At the 
most they are suggestive.” After the publication of the additional note, however, 
the medical profession accepted the conclusion of the Commission more gen- 
erally. During this work, and for months subsequently, continued investi- 
gations were carried on by members of the Board, searching for the causa- 
tive organism of yellow fever, but it has not yet been found. It was discovered 
that the disease could be conveyed not only by the puncture of the mosquito, but 
by the injection of the blood serum of a yellow-fever patient into the system of a 
non-immune. It was further discovered that this blood serum could be filtered 
through a porcelain filter and yet retain its power to convey the disease. It was 
Dr. Carroll’s theory that the cause of the disease is some micro-organism so ex- 
cessively small as to fail to reveal itself to the highest powers of the microscope, 
and this view has generally been accepted. 
LATER WORK IN CUBA BY GUITERAS AND JOHN W. ROSS. 
Additional experiments were carried on in 1901 by the Havana Board of 
Health, under Dr. Juan Guiteras. In a number of cases the disease was experi- 
mentally conveyed by the bites of infected mosquitoes. Later in the autumn and 
winter of 1901, very careful experiments were carried on at Las Animas Hos- 
pital by the Director of the Hospital, Surgeon John W. Ross, of the U. S. Navy, 
and these experiments were made for the purpose of setting at rest the theory 
still adhered to, by many, of the transmission of the disease by fomites. Certain 
rooms in the hospital were made mosquito-proof and numerous bundles of bed- 
clothes and bedding, which had recently been used in sickrooms and on the 
persons of people ill with yellow fever, were placed in these rooms. Eight men, 
recently arrived on the Island, 5 Spanish, 2 Italian and 1 English, were taken 
as subjects for experimentation. They were placed under observation for 7 days, 
then transferred to the experiment room, where they were kept for 7 days. They 
were then kept under observation for 7 days longer, with the result that all 
emerged from the experiment in good health. 
WORK DONE IN BRAZIL BY THE SAO PAULO AND THE FRENCH COMMISSIONS. 
In spite of the perfect scientific character and convincing nature of the work 
done at Havana, the medical world was by no means unanimous in accepting 
the conclusions. Among the first countries to take up the work was Brazil. Dr. 
