Disinfection for the prevention of yellow fever and malaria having practically resolved itself into mosquito destruction, the scientific study of culicides has assumed much interest and importance. Investigations in this direction are being made by the United States Public Health and Marine-Hospital Service.
Passed Assistant-Surgeon Francis of that Service some time ago reported that the fumes of pyrofume, a liquid derived by fractional distillation from pine wood, are deadly to Stegomyia fasciata and Culex pungens.1 Mosquitoes placed in cages on the floor of a room containing the fumes from 265 cubic centimeters of this liquid per 1,000 cubic feet of air space were found dead after one hour. While in this proportion pyrofume is not injurious to metals, fabrics, paint and colors, it has been found that in greater amounts it softens varnish and leaves a deposit on surfaces. Its inflammable nature will also render it objectionable as a