rUMIGANTS 375 



carry about heavy iron pots and barrels of sulphur. As to expense, he shows 

 that at one dollar per pound the 25 grams used per one thousand feet cost some- 

 what less than half a cent, whereas two pounds of sulphur per one thousand 

 cubic feet would cost six cents. Moreover, it is pointed out that in practical 

 work on a large scale the expense and trouble of hauling the disinfecting 

 equipment from one place to another would be greatly diminished. He con- 

 cludes that while mercuric chloride can not altogether take the place of sulphur, 

 it has a hitherto unrecognized effect, especially with reference to flies and 

 mosquitoes. 



OTHER FUMIGANTS. 



In the early anti-mosquito work in European cities different substances were 

 experimented with. Fermi and Lumbao, in their outlined experiments, recom- 

 mend chlorine gas. These writers advise that 4 or 5 spoonfuls of chloride of 

 lime be placed in a dinner plate and that from 5 to 10 cubic centimeters of crude 

 sulphuric acid be poured upon it. This liberates the chlorine gas which kills 

 the mosquitoes. The same writers claim that the vapors of chloral act rapidly, 

 killing mosquitoes in a few seconds. Celli and Casagrandi in their early ex- 

 periments in Italy recommended a substance called larycith III, which is prob- 

 ably a misprint for larvicide. This is dinitrocresol, a yellow aniline color, 

 which Idlls adult mosquitoes when burned in small quantities. Formaldehyde 

 gas was recommended in 1890, but has been found to have almost no insecticidal 

 value. 



Doctor John B. Smith found that the powdered stramonium or jimson weed 

 {Datura stramonium) can be burned to advantage in houses. He recommends 

 8 ounces to fumigate 1000 cubic feet of space. He states that it should be made 

 up by the druggist with nitre or saltpetre, 1 part to 3 parts of Datura, so as to 

 bum more freely. He states that the fumes are not poisonous to human beings, 

 are not injurious to fabrics or to metals, and can be used with entire safety. 

 He suggests that it be burned in a tin pan or on a shovel. (See Bulletin 216, 

 New Jersey Agricultural Experiment Station, page 12.) 



A long list of fumigants is given by Celli in his work entitled " Malaria ac- 

 cording to the new researches," and this list has received a critical review 

 which carries at the same time the results of certain experimental work by 

 Arthur J. Kendall, in Bulletin No. 1 of the Laboratory of the Board of Health, 

 Isthmian Canal Commission, Panama, 1906. Bulletin No. 3 of the same 

 service (1906) contains an account of experiments in practical culicidal fumi- 

 gation, also by Doctor Kendall. 



The burning of dried orange peel has been recommended as a deterrent against 

 mosquitoes, but there seem to be no records of conclusive experiments, although 

 we have been assured of its efficacy by a Japanese physician Adsiting the United 

 States. 



In the course of his experiments with different disinfectants against mos- 

 quitoes, Eosenau, of the Public Health and Marine-Hospital Service, in Bulletin 

 No. 6, of the Hygienic Laboratory (September, 1901), did his principal work 

 Avith the formaldehyde and sulphur dioxide. We have mentioned his con- 



