USE OF GASES AGAINST HOUSEHOLD INSECTS 457 



experimental tests with sulfur dioxide and concludes that 

 it is unexcelled as an insecticide. "He shows that very 

 dilute atmospheres of the gas will quickly kill mosquitoes, 

 and that it is quite as efficacious when dry as when moist. 

 He shows that it has surprising power of penetrating 

 through clothing and fabrics, and that it will kill mos- 

 quitoes even when hidden under four layers of toweling in 

 one hour's time and with very dilute proportions." 



Directions for use. — The rooms to be fumigated are 

 made as tight as possible in the same manner as described 

 in the case of hydrocyanic acid gas. All objects of a 

 metallic nature should be removed or tightly covered with 

 paper or coated with vaseline. The sulfur should be 

 used at the rate of 2 pounds to each 1000 cubic feet of 

 space. If the room is rather open, this quantity may be 

 increased. The sulfur may be burned by putting it in 

 an old kettle, baking pan, or similar dish that is not held 

 together with solder, and setting it on bricks or in a pan of 

 cold ashes to keep it from burning the floor. A teacupful 

 of wood alcohol poured directly into two pounds of sulfur 

 and then lighted will serve to burn the sulfur completely 

 and readily. Sulfur in the form of candles is for sale at 

 most drug stores. These are particularly convenient 

 because they burn readily when lighted. The following 

 directions for fumigating with sulfur dioxide given out by 

 the health authorities of New Orleans cover the ground so 

 clearly that we repeat them here : — 



" Remove all ornaments of metal, such as brass, copper, 

 silver, and gilt from the room that is to be fumigated. 

 All objects of metallic nature which cannot be removed 

 can be protected by covering the objects tightly with paper, 

 or with a thin coating of vaseline applied with a brush. 



