CAMPHOR-PHENOL 369 



ago a man in Hawaii patented an appliance for producing this volatilization 

 which is all that can be wished for. The powder is placed on a brass or other 

 metal screen above the chimney of a kerosene lamp, the idea being to dissipate 

 the vapor of the volatile oil. According to Mr. Henshaw the effect of this 

 method is most remarkable. " Besides being very economical in powder there 

 is only a very slight odor perceptible and that is not at all unpleasant. The 

 effect on the mosquitoes is immediate and all that can be wished for. They 

 simply clear out.^' Another method of burning the powder that has often been 

 employed by the writer consists in puffing it from an insufflator into a burning 

 gas jet. This is a simple method where gas is used for illuminating purposes 

 and produces a vapor that suffocates all mosquitoes and other insects that may 

 be in the room. 



While pyrethrum has been mainly used as a means of clearing living-rooms 

 of mosquitoes, and has ordinarily been burned in the rooms while they were 

 occupied, it has also come into use in the extensive fumigation of houses in cases 

 of epidemics of yellow fever, in the effort to rid houses of mosquitoes and to 

 destroy all mosquitoes hibernating in cellars, attics, or disused rooms of resi- 

 dences, as well as similarly hibernating mosquitoes in bams and outhouses. 

 While reasonably effective for such purposes it does not seem to be as effective 

 as some of the other substances to be mentioned later and at the same time it is 

 more expensive. 



As to the quantity to be used, the regulations of the Board of Health of N'ew 

 Orleans, adopted May 25, 1903, specify the burning of 4 ounces of pyrethrum 

 powder to 1000 cu. ft. of space, but the President of the Board, Dr. Edmond 

 Souchon, a little less than a year later wrote to the U. S. Marine-Hospital 

 Service that this quantity was found insufficient for thorough work, and that 1 

 pound of the powder to every 1000 cubic feet of space is necessary. As a matter 

 of fact, however, the 'New Orleans Board of Health abandoned pyrethrum about 

 that time on account of the fact that the fumes do not kill mosquitoes but simply 

 stupefy them, so that they have to be brushed up and burned. Not willing to 

 run the slightest chance of having mosquitoes survive by escaping destruction 

 after being stupefied, the Board decided to use sulphur fumes in preference. 



Nevertheless, on account of the fact that the fumes are not noxious to human 

 beings, there still remains a decided use for pyrethrum in everyday work in 

 mosquito-inhabited regions. 



MIMMS CULICIDE OR CAMPHOR-PHENOL. 



During a yellow fever outbreak in New Orleans, in the summer of 1905, a Mr. 

 Mimms, a chemist of New Orleans, invented a mosquito fumigant which was 

 experimented with rather extensively and found to give good results. It was 

 made of equal parts by weight of carbolic acid crystals and gum camphor. The 

 acid crystals were melted over a gentle heat and poured slowly over the gum, 

 resulting in the absorption of the camphor and a final clear, somewhat volatile, 

 liquid with rather an agreeable odor. This liquid is permanent and may be 

 kept for some time in tight jars. In fumigation work 3 oz. of this mixture is 



