The Campaign in Havana 251 



select honest laborers, and practically no thefts 

 occurred. As soon as the brigade completed 

 one fumigation, the next was started. Occasion- 

 ally the removal of paper, cleaning up, etc., was 

 delayed for a day or two and the men were em- 

 ployed at this work while other houses were closed 

 dttring fumigation. 



In Havana houses were being fumigated before 

 February, 1 901, and where pyrethrum was used 

 at that time it was bought from local merchants. 

 The results varied considerably. Sometimes the 

 mosquitoes were killed, and at other times they 

 were not. The quality of the pyrethrum varied 

 greatly. Samples were obtaind from the dealers, 

 and tests made to determine the quality on which 

 the quantity needed for a given volume of space 

 depends. 



A room at Las Animas Hospital was used for the 

 fumigation tests. The cubic content was about 

 1500 cubic feet. A glass transom over the door 

 served as an observation window to note the effect 

 of fumes on mosquitoes subjected to fumigation. 

 It so happened that house flies were in the room 

 during the first series of tests, and after the killing 

 of Aedes calopus it was noted that the flies still 

 lived. The amount of pyrethrum per 1000 cubic 

 feet was increased until it was sufficient to kill the 



