398 APPENDIX 



In the case of vessels, when treated for yellow fever infection, the process shall 

 be a simultaneous fumigation with sulphur dioxide, 2 % volume gas, and two 

 hours' exposure, in order to insure the destruction of mosquitoes. 



In the case of vessels when treated for plague the process with sulphur dioxide 

 shall be as follows: 



Without cargo: The simultaneous fumigation with sulphur dioxide gas not less 

 than 2% for six hours' exposure. 



With cargo: Fumigation with sulphur dioxide gas, 4 %, six to twelve 

 hours' exposure, according to stowing. 



Infected vessels may require partial or complete discharge of cargo, and frac- 

 tional fumigation for efficient deratization. 



Pyrethrum. The fumes of burning pyrethrum may be used to destroy mos- 

 quitoes in places where there are articles liable to be injured by the use of sulphur. 



Four pounds per 1000 cubic feet space for two hours' exposure will kill, all or 

 practically all of the mosquitoes but precautions should be taken to sweep up and 

 destroy any that may have escaped. 

 Pyrethrum stains walls, paper, etc. 



The oxides of carbon, as used at Hamburg, are efficient to destroy rats but do 

 not kill fleas or other insects. They are obtained by burning carbon, coke, or char- 

 coal, in special apparatus, and the gas as produced consists of about 5 % 

 carbon monoxide, 18 % carbon dioxide, and 77 % nitrogen. 



Twenty kilos of carbon, coke, or charcoal are used for every 1000 meters of 

 space. The gas is allowed to remain in the ship for two hours and from seven to 

 eight hours are allowed for it to leave it. This is about equivalent to i 1/3 pounds 

 of carbon (coke) to 1000 cubic feet of air space. As this gas is very fatal to man 

 and gives no warning of its presence, being odorless, a small amount of sulphur 

 dioxide should be added to give warning of its presence. As it does not kill fleas 

 it cannot be depended on for complete work, where there is evidence of plague 

 among rats on the vessel, as the infected fleas would infect the rats coming aboard 

 after the deratization. 



The articles named as disinfectants which can obviously destroy animal life can 

 be used for that purpose when applicable, as steam for bedding, fabrics, etc. For- 

 maldehyde is not applicable for this purpose. 



For fleas the best insecticides are (i) crude petroleum (fuel oil) which is at times 

 called Pesterine, (2) an emulsion of kerosene oil made as follows: kerosene 20 parts, 

 soft soap i part and water 5 parts. The soap is dissolved in the water by aid of 

 heat and the kerosene oil gradually stirred into the hot mixture. 



For cockroaches there is nothing so good as sodium fluoride. By sprinkling 

 the powder about the haunts of the cockroaches they are gotten rid of in a few days. 



For exterminating rats and in this way secondarily the rat-fleas besides the 

 ordinary poisons such as As., P., etc. Rucker has recommended a poison composed 

 of plaster of Paris, 6 parts, pulverized sugar i part and flour 2 parts. This mixture 

 should be exposed in a dry place in open dishes. To attract the rats the edge of 

 the dish may be smeared with the oil in which sardines have been packed. 



Wise and Minett report good results from the use of crude carbolic acid as a 

 larvicide for mosquitoes. They added about i teaspoonful for each 2 cubic feet 

 of water in the pool. Of course the ordinary method for destroying mosquito larvae 

 is by covering the surface of the water in the cistern or pool with a layer of petroleum. 



