Progress of the Panama Canal 



473 



Toro Point to the Colon light. This 

 breakwater will probably be designed 

 in two parts, each about 4,000 feet long, 

 with an opening between them 700 

 to 800 feet wide for the entrance of 

 ships. 



REMOVING SOURCES OF INFECTION 



One of the most interesting features 

 of the work has been the blood exam- 

 inations to determine the malarial index 

 of infection of the native population. 



About 80 per cent of the natives, says 

 Colonel Gorgas, at the present time 

 have the malarial parasite in their blood. 

 Four times out of five when 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 sani- 

 tary measures prevent it. There are 

 two means of protection — quinine, which 

 is harmless to man and fatal to the ma- 

 larial parasite, and the destruction of 

 the mosquito. 



The following description of the clean- 

 ing of the town of Culebra is an in- 

 stance of what is being done by our 

 American sanitary corps throughout the 

 canal zone : 



The brush in the vicinity of the town 

 has been removed and the streets, which 

 are badly paved, are being kept clean. 

 All manner of water containers were 

 found buried under the brush, removed, 

 and by removing the same the breeding 

 places of the stegomyia were destroyed. 

 The mosquito- proof water barrels have 

 been regularly inspected and are in good 

 condition. As a relatively large non- 

 immune population live at Culebra, 

 every effort is being made to stop the 

 breeding of stegomyia in the vicinity. 

 The garbage from each house is regu- 

 larly removed, as well as the nightsoil 

 from the pail closets that now exist. 

 The surface drains are being kept in 

 shape, and no mosquito larvae are visi- 

 ble therein. All hogs have been re- 



moved from the town and all horses 

 and cows are kept tied to stakes to pre- 

 vent the ruination of the existing sys- 

 tem of drainage. 



THE MOSQUITO CAMPAIGN IN PANAMA 

 CITY 



Colonel W. C. Gorgas, Chief Sanitary 

 Officer of the Isthmus, in his official re- 

 port for July, 1905, describes the cease- 

 less fight waged by his corps against 

 mosquitoes : 



"The Administration Building in 

 the city of Panama has been kept 

 ' stegomyia proof ' during July. No 

 eggs of stegomyia or other mosquitoes 

 were found during the month, although 

 all containers in this building, which is 

 quite large, have been carefully and con- 

 tinuously scrutinized daily . This build- 

 ing is being fumigated every two weeks. 

 After the two fumigations in July the 

 floors were carefully swept and no mos- 

 quitoes were found, although the fumi- 

 gations were strong enough to kill the 

 flies which had entered the building. 

 It takes a longer and strongerfumigation 

 to kill flies than to destroy mosquitoes. 

 There are about 400 employes, mostly 

 non-immune Americans, in this build- 

 ing, who are specially anxious not to 

 contract yellow fever, and it is reported 

 by them that no mosquitoes are present. 

 The building is undoubtedly a safe place 

 at present for non-immunes. 



' ' There is quite a noticeable decrease 

 in the number of stegomyia present in 

 Santa Ana Park since the same was 

 trimmed out by this department in June. 

 No cases of yellow fever or suspects 

 were found in this vicinity during Juty, 

 although it seemed to be a focus in pre- 

 vious months. 



' ' The house-to-house inspection force 

 has been increased, and some sections 

 of the town are inspected every four 

 days, and all houses and yards are in- 

 spected at least every six days. 



' ' Whenever the inspector finds a 

 water deposit containing mosquito 

 larvae the same is emptied out. Every 



