32 Proceedings of the First Convention 



of animals, etc., and seldom goes far away from its place of 

 birth. In a town or province, especially in tropical countries, 

 where yellow fever prevails, it is important to carry out work 

 relative to protection against this mosquito. The first thing 

 to do is to screen your patients. If you can isolate your cases 

 promptly and screen them, so that mosquitoes cannot be in- 

 fected, you have half the battle won. At the same time sup- 

 plement this by using oil on the water barrels to kill the 

 larvae present. Then look after the general policing of the 

 premises, draining small pools, filling up cattle tracks, destroy- 

 ing broken bottles and flower pots. These should not be 

 overlooked. 



In this work our service has had considerable experience 

 in epidemics, and the plan has been to first isolate the cases 

 of fever and screen them as quickly as possible, then screen 

 the containers of water around houses if a city is without a 

 modern water supply, and the use of oil to kill the larvae 

 present. Another function that falls in their province is that 

 relating to maritime quarantine — the surveillance of vessels 

 sailing from infected ports. We know, and it is generally 

 accepted, that the mosquito is a transmitter of infection. If a 

 vessel can leave an infected port with no infected mosquitoes 

 aboard and no fever cases develop on a five days' trip, that 

 vessel is safe. This has been proved by work of our officers 

 on duty in Central American ports, where vessels were dis- 

 infected immediately before departure for the purpose of killing 

 the Stegomyia. Of course, the possibility arises of a person 

 having been infected before the vessel left ; but that would 

 develop during the five days at sea or the danger of spreading 

 infection could be eliminated by detaining the vessel in quar- 

 antine a very short time, only sufficient to complete the five 

 days from date of sailing. Such procedures simplify the 

 problem and obviate the long quarantine detention. 



The question naturally arises. What are the best disin- 

 fectants or insecticides for killing mosquitoes? On ships, 

 sulphur is the best agent for this purpose ; it should be burned 

 in the proportion of one pound to i,ooo cubic feet and two 

 hours are necessary. Another factor in dissemination is a 

 railroad car coming from an infected place. The best agent 

 to use in killing mosquitoes in such coaches is hydrocyanic acid 

 gas. For this purpose the car should be placed on a siding 



