EXAMPLES OF MOSQUITO EXTERMINATTVE MEASURES. 95 



in the same month 9 of the medical stall. Thirty-six Roman 

 Catholic sisters were brought over as female nurses, and 24 died of 

 yellow fever. On one vessel 18 young French engineers came over, 

 and in a month after their arrival all but one died. Now that the 

 mosquito relation is well understood, it was found during the first 

 two years under Doctor Gorgas that although there were constantly 

 one or more yellow-fever cases in the hospital, and although the nurses 

 and doctors were all nonimmune, not a single case of yellow fever 

 was contracted in that way. The nurses never seemed to consider 

 that they were running any risk in attending yellow-fever cases 

 night and day in screened wards, and the wives and families of 

 officers connected with the hospital lived about the grounds, knowing 

 that yellow fever was constantly being brought into the grounds 

 and treated in near-by buildings. Americans, sick from any cause, 

 had no fear of being treated in the bed immediately adjoining that 

 of a yellow-fever patient. Colonel Gorgas and Doctor Carter lived 

 in the old ward used by the French for their officers, and Colonel 

 Gorgas thinks it safe to say that more men had died from yellow 

 fever in that building than in any other building of the same capacity 

 at present standing. He and Doctor Carter had their wives and 

 children with them, which would formerly have been considered 

 the height of recklessness; but they looked upon themselves, under 

 the now recognized precautions, as safe almost as they would have 

 been in Philadelphia. 



No figures of actual cost of the antimosquito work either in Habana 

 or in the Panama Canal Zone are accessible to the writer, but it is 

 safe to say that it was not exorbitant and that it was not beyond 

 the means of any well-to-do community in tropical regions. 



WORK IN RIO DE JANEIRO. 



One of the most difficult problems of this character was that of 

 freeing Rio de Janeiro from its reputation as the great yellow fever 

 center. The difficulties were very great, and the amount of money 

 required for efficient work was enormous. Rio de Janeiro has a 

 population of more than 800,000 people; it extends over an area of 

 430 square miles; it is very irregular in its topography, varying in 

 altitude from 1 to 460 meters (3 feet to 1,509 feet) above the sea 

 level; it has 82,396 houses, and, as in all great centers of population, 

 the inhabitants of very many of the houses, if not resisting the 

 efforts of the sanitary authorities, surely did not facilitate them. 

 The effort was begun in April, 1903, under the direction of the public- 

 health service, but the organization effected was of a temporary 

 character and needed the passage of new laws by congress, which 

 was effected in January, 1904, and resulted in the reorganization 



