DISAPPEARANCE OF MALARIA 31 



and in 1902, when Ross was asked by the Prince d'Aren- 

 berg to visit the place and advise as to measures to be 

 taken, there were 1,551 cases. Ross directed the filling 

 up of the breeding pools. The marshes were filled up with 

 sand, the irrigation channels were deepened or treated 

 with kerosene oil (which spreads as a fine film, and chokes 

 the gnat larvae), and the cess-pits were rendered unin- 

 habitable by chemical treatment. In one year the cases 

 of malaria fell to 21 4, in 1905 they were only thirty-seven, 

 and now the Suez Canal Company officially reports, 

 "all trace of malaria has disappeared from Ismailia." 

 The same satisfactory results have been obtained in Port 

 Said, in Khartoum, in Port Swettenham of the Federated 

 Malay States, in Havannah City, in Panama, and, in 

 fact, wherever intelligent conviction has led to the active 

 and complete employment of the methods necessary for 

 the destruction of the gnats. Under the British Gov- 

 ernment of India and the African and West India 

 Colonies, little has been done. Why ? Because of the 

 handmaiden theory and the ostrich-like refusal of our 

 officials to face and accept the master. 



An even more wonderful and beneficent result has 

 been obtained in the case of that terrible disease " Yellow 

 Jack," or " Black Vomit " the yellow fever. Owing to 

 the discoveries and definite proof by Ross as to the part 

 played by gnats in malaria, the able medical men in the 

 public service of the United States of America have 

 thoroughly examined experimentally the mode of infec- 

 tion of human beings with the germ of yellow fever, and 

 have conclusively proved that infection is solely and en- 

 tirely due to the bite of one species of gnat the 

 Stegomyia fasciata. They have proved to absolute 

 certainty that yellow fever is not carried through the 

 air, nor by food or drink, nor by contact with infected 

 persons or their cloths or emanations, but only by the 

 fasciate gnat, a house-frequenting species, which sucks 

 the blood of a yellow fever patient, and after twelve 



