230 DISCOVERY OH. 



1901. His death added another name to the roll of 

 martyrs to scientific investigation. High courage and 

 an unselfish spirit led him to accept the invitation to 

 take part in a most dangerous expedition ; and he died 

 that others might live. 



One practical result of the discovery of the cause of 

 yellow fever was that it made possible the construction 

 of the Panama Canal, which had been abandoned as 

 hopeless. It was not a hostile army or political diffi- 

 culties that obstructed the progress of the work, not 

 mountain chain or desert waste, but an insect which 

 raised a barrier of disease and death between endeavour 

 and accomplishment. 



For four centuries the narrow Isthmus of Panama was 

 regarded as the white man's grave. " Yellow Jack," 

 or yellow fever, prevented Spaniards, French, or English 

 from founding colonies there, and it was abandoned to 

 negroes and half-breeds, who were immune to the disease. 

 When Ferdinand de Lesseps, the constructor of the 

 Suez Canal, commenced to cut the canal through the 

 Isthmus of Panama, the chief obstacles in his way were 

 yellow and malarial fevers. His men died like flies. 

 It has been stated that before the work was finally 

 abandoned by the French, a human life had been 

 sacrificed for every cubic yard of earth excavated. 

 Out of every hundred men employed upon the work, 

 at least eighteen were sacrificed to a disease which is 

 now known to be preventable, and many more were 

 rendered helpless. 



When the United States took over the control of the 

 canal, the Government set to work to exterminate 

 the mosquitoes responsible for the transmission of 

 yellow fever and malaria. An army of sanitary officers, 

 organised by Colonel W. C. Gorgas, was employed in a 



