DESTRUCTIOX OF MOSQUITOES, ETC. 669 



oil, such as linseed oil, to reduce the strength, or by some other 

 pulicide. Recently Messrs. Newton Chambers & Co., of Birming- 

 ham, forwarded me two consignments of twenty gallons each of 

 Izal and Izo-izal with the idea that I might carry out experiments 

 on a wholesale scale for the destruction of fleas, flies and other 

 insects, similar to some which I carried out at the Quarantine Island 

 of Motuhihi and Rangitoto, Auckland, N.Z.^ 



Mr. Wynter Blyth, writing of fleas and disinfectants in the 

 Indian Medical Gazette, March, 1908, speaking of the need for a 

 rehable substance which will combine good disinfecting properties 

 with a high insecticidal value, states that Dr. Hossack claims that 

 phenyle in the strength of 1 in 500 fulfils all the requisites of a good 

 pulicide in that it paralyses the flea in a few seconds. Dr. H. M. 

 Crake, in " Plague in Calcutta," 1906, claims that the best solution 

 for practical use appears to be izal. In my opinion petroleum is 

 the best. 



Mr. Wynter Blyth's series of experiments showed that petroleum 

 both Hght and crude, purisine, crephol and izo-izal were the best 

 pulicides, and that the last named also had a carbolic acid co- 

 efficient of ten. In a report issued by the United States Marine 

 Hospital Service, July, 1910, Maurice Mitzmain makes a classifica- 

 tion of the potency of the different substances suggested for 

 destroying fleas. With kerosene (full strength) apphed to fleas 

 there was no movement in 10 to 20 seconds ; dead in 30 seconds. 

 No other substance gave such rapid and certain results. This has 

 been my experience since I first in Egypt used to demonstrate, by 

 pouring kerosene into a test tube, pouring it out, and then dropping 

 in a flea or fly, the almost instantaneously lethal effect of kerosene. 



I have found, however, that for ridding animals, such as dogs, 

 from fleas, izo-izal is almost equally efficacious, and being also a 

 disinfectant and not hable to lose its virtue so rapidly by evapora- 

 tion, has a sphere of usefulness where kerosene has its limitations 

 for prac'ical use. Where it is not advisable to prolong the use of 

 kerosene in houses after carpets and furniture have been replaced, 

 owing to the odour, one can use a ten per cent, solution of creolin, 

 cylUn, izal, cofectant, phenyle, kerol, or in fact any of the now 

 well-known disinfectants of the higher phenol series. Although all 

 these disinfectants are boomed as the " one and only efficient," as 

 a matter of fact the firms with estabhshed reputations, such as 

 Little, McDougall, Quibell, Cook, Jeyes, and Cooper, all put such 

 effective preparations on the market that it is unfair, or savours 

 of commercialism, to single one out for special mention. 



Schools can be kept free of fleas by using sawdust saturated 

 with such disinfectants sprinkled on the floors, and a weekly 

 scrubbing, using water in which a disinfectant has been dissolved. 

 Sprinkling animals with pyrethrum powder will also keep fleas away 

 from them. The most rational means, however, of keeping fleas 

 from houses is to flood them with sunlight. 



1 Recorded in Journ. Royal Sanitary Inst., 1909. 



