ENTOMOLOGY

THE CONTROL OF HUMAN LICE 3~534 (1910) with special reference to ships, and in Entomology Btill. 60(1906) with reference to general fumigation.1. Clayton gas is generated by burning common roll brimstonein an oven or generator outside of the building. A very high heat isgenerated. The gas is passed Over two baffle plates before reachingthe outlet pipe which is cooled by water circulating in pipes aroundit in an ordinary steam boiler tank. The gas then is passed into thebuilding to be fumigated. This gas is a mixture of sulphur dioxideand sulphur trioxide. As the gas is heavier than air there must becirculation through the roof of a building or hatch of a ship until thegas begins to come out in quantity.~. Bum sulphur candles, being careful to isolate them by sufficientmetal from all woodwork, at rate of 4 pounds per 1,000 cubic feetfor .6 hours.b. Cyanide is one of the best known gases used for fumigation.1. Sodium cyanide only is now available. Generate in earthenjars, placing in the jar 1112 oz. sulphuric acid and ~ oz. water to everyounce of cyanide to be used. Arrange the cyanide in a package suspendedover the jar so that it can be released by the operator at adistance by pulling or releasing a cord. The gas is generated veryrapidly and is exceedingly dangerous. Use 10 oz. of cyanide for each1,000 cubic feet and expose for ~ hours. This will kill all other insectspresent.~. Potassium cyanide should be used at the rate of 1 oz. cyanideto 1 oz .. sulphuric acid, and 3 oz. of water.s. Chlorocyanogen (CICN), in experimental work, gives promiseof being fully as effective as HeN and much safer to use, because theirritation of the membranes of the nose and eyes gives warning of anyleak long before sufficient gas has escaped to produce any toxic effect.The most practical method for fumigation of any kind would be amobile motor fumigator with hose attachments capable of treating anybuilding, tent, or car. If this unit had a tight fumigation room, garmentscould be hung therein and practically fumigated. The installationshould be equippe~ with generators for cyanide, formaldehyde, orsulpllUr fumigation, and be placed in charge of practical fumigationexpert~.Vacuum fumigation has received several very successful trials. On theMexican border it has been used by the Public Health Service, wherea hydrocyanic acid gas fumigation is used. Many steam sterilizers nnwin use are available for gas fumigation. The following formulre haveheen tested and proven satisfactory:1. For chests, trunks, and tightly-packed garments ~5-inch vacuum,