BY DR. A. JEFFERIS TURNER, M.D. LOND., D.P.H. CAMB. 111 
investigating. The true nature of this outbreak had not 
been recognised until 35 cases had occurred, with 11 deaths. 
No precautions had therefore been taken with regard to 
the disinfection of bedding and clothing; but the disease 
had not been contracted by the nurses nor by the men 
who washed the clothes. Indeed a little inquiry showed 
the presence of contaminated clothing in all of the eight 
barrack-rooms without apparent detriment to the occupants. 
This threw grave doubt on the accepted theory of pro- 
pagation by infected fomites. Yet at the same time, a 
prisoner who had been in strict confinement in a cell of the 
guardroom for seven weeks contracted the yellow fever. 
Eight other prisoners in the same room escaped infection, 
though one of them continued to occupy the bunk vacated 
by the sick man. It was exceedingly difficult to explain 
this isolated case, but it was conjectured that some insect 
capable of conveying infection, perhaps a mosquito, had 
entered through the cell window, and bitten this particular 
prisoner. This was of course, merely a supposition, but 
it was not apparently possible to explain the case in any 
other way. 
It seemed therefore advisable to Dr. Reed that the 
scheme of work planned out by the commission should be 
altered, so that its chief endeavour should be turned to the 
proving, or disproving the agency of the mosquito as an 
intermediate host in the spread of yellow fever. For- 
tunately, the mosquito selected for experiment, the 
Stegomyia fasciata, proved to be the right one. As the 
experiments proposed involved grave danger to life, it was 
considered that the members of the commission should 
run the risk themselves, before subjecting anyone else to it. 
The first successful experiment was performed on Dr. Carroll. 
The insect, which had been hatched and reared in the 
laboratory had been caused to feed on four cases of yellow 
fever, twelve, six, four and two days previously. Carroll 
duly contracted a severe attack of the disease from which 
his life was in the balance for several days, but eventually 
he recovered. Another member of the commission, Dr. 
Lazear, subsequently succumbed to a fatal attack after 
being bitten by a mosquito in the fever ward, but in his 
case the infection was an accidental one, and not having 
