748 SANITATION OF THE PANAMA CANAL ZONE. 



yards should bo thoroughly cleaned, so that there will be no old 

 bottles or cans left around. The water supply should be piped in, 

 so that the people w\\\ not desire to have water in containers. Sewers 

 should be put in, so that there will be no excuse for people to throw 

 slop water in the yards. All standing puddles should be drained and 

 kept dry. Streets should be paved and kept well swept, and the 

 garbage carefully collected, with a view to decreasing to the mini- 

 mum all trash capable of retaining fresh water in any way. When 

 Panama has been in this state for a month or two we wnll be in the 

 same condition that Habana is, as the result of just such operations 

 as I have described above. When Panama has thus been freed from 

 yellow fever we will not have any more until a man sick from yellow 

 fever is introduced from some infected point without. This we will 

 prevent by a proper system of quarantine, just as Habana has done 

 for the past three years. 



Thus I can see the entire possibility of protecting our laborers on 

 the canal during the whole time of its construction from one of the 

 two greatest causes of former mortality. 



But I think that probably a more important problem for the 

 health of our laborers, and certainly a much more difficult one to 

 deal with, is that of malaria along the line of the canal. The 

 10,000 natives living along the canal are distributed in about 20 small 

 villages. These people are very generall}^ infected with malaria, A 

 recent microscopical examination of the blood of people, taken at 

 random at various points along the line, in several hundred cases 

 showed parasites in the blood of 50 per cent of these people on the 

 first examination. This means pretty certainly that about 80 per 

 cent of the natives at the present time have the malarial parasite in 

 their blood. Four times out of five, Avhen a female Anopheles bites 

 one of the natives she becomes infected, and when she, in turn, bites 

 one of our nearby laborers he becomes infected. It is thus evident 

 that our force will rapidly be used up, just as was the French, unless 

 our sanitary measures prevent it. 



Now, we can approach this problem from two sides; either on the 

 side of doing away with the infected human being so that he can 

 not infect the mosquito, or doing away with the mosquito so that she 

 can not transmit the parasite from the diseased to the well. If we 

 could kill these 10,000 natives and keep our laborers aw^ay for four 

 or five months until all previousl}^ infected mosquitoes had died, the 

 problem would be settled; but our superiors would very properly 

 not sanction this very drastic measure, even if proposed by us. But if 

 we have some substance which could 1)0 introduced into the circula- 

 tion of the infected man, and kill the parasite and at the same time 

 not be injurious to man, we would accomplish the same object just 



