2 SCIENCE FROM AN EASY CHAIR 



and Panama have not merely done a piece of sanitary 

 cleaning up; they have first imagined and then created, 

 by the force of human will, directed and maintained by 

 conviction of the reality of science, a new thing the 

 tropics without deadly fever, the tropics as a healthy and 

 welcome home for the white man. That is comparable to 

 the work of a great artist in the directness of its appeal ; 

 it is in its actual detail the result of the combination of 

 the skill of the engineer with the foresight and absolute 

 domination of his human agents of a military genius. 



For this magnificent work the highest credit is due to 

 the United States chief sanitary officer, Colonel Gorgas. 

 It is well known how the American Medical Commission 

 in Cuba proved six years ago that yellow fever is con- 

 veyed from man to man solely and entirely by a gnat 

 common in Central America, known as Stegomyia> and 

 further, how by carrying out measures for preventing the 

 entrance of these gnats into dwelling-houses, and especi- 

 ally by keeping them away from yellow fever patients so 

 that they fail to obtain and carry the yellow fever germ, 

 even if they do bite healthy men, Colonel Gorgas and 

 his associates practically eradicated yellow fever in Cuba 

 The bite of the Stegomyia gnat is the only way in which 

 a man can acquire yellow fever, and the gnat which bites 

 him must have taken up the germs of yellow fever from 

 another man twelve days (no less) previously. 



The application of this knowledge and the methods 

 devised to give it effect is what has now rendered the 

 construction of the Panama Canal by the United States 

 Government possible. The French Canal Company em- 

 ployed an army of labourers, numbering from 15,000 to 

 18,000 men. They lost, almost entirely by death from 

 yellow fever and malaria, so many of their workmen that 

 others refused to undertake the deadly job, and there was 

 a general panic. The death-rate was in 1884 over 60 per 



