_ AMERICAN MUSEUM GUIDE LEAFLETS 
of the Commission were at first quite unconvinced by the Havana 
investigations and the practical application of their conclusions. As 
the non-immune population on the Isthmus increased, yellow fever 
became epidemic. In April, 1905, several of the higher officials were 
stricken, and panic and demoralization threatened. In June, 1905, 
the Governor and Chief Engineer of the Commission reeommended 
that General Gorgas and other adherents of the “‘mosquito theory” 
should be recalled and ““men with more practical views’’ appointed 
in their places. President Roosevelt, however, supported the sani- 
tary officers with his accustomed vigor, and Mr. John F. Stevens, 
who was appointed in place of the former Chief Engineer, was in 
cordial sympathy with General Gorgas’ plans. The work now 
moved forward rapidly. Mosquito breeding was reduced to a mini- 
mum by clearing away brush and undergrowth, by draining low lands, 
and by the use of larvicides. Houses were screened, and in partic- 
ular malaria and yellow fever patients were rigorously isolated from 
the access of mosquitoes. Quinine was provided, and its systematic 
use as a prophylactic was persistently urged upon the working force. 
The results of this sanitary work were as strikingly dramatic as 
those obtained at Havana. In 1904 and 1905 there were 35 deaths 
of employees from yellow fever on the Isthmus, but by the end of 
the latter year the situation was under control. In May, 1906, there 
was one case at Colon and there has not been a single case on the 
Isthmus since that date. 
The deaths from malaria have been reduced from 233 in 1906 to 
3 in 1916 with a larger working force, and the table of case rates 
below quoted from Hoffman’s monograph is eloquent of the results 
achieved. 
