Practical preventive medicine . Pig. 74.—Oilers at work in marsh. (Gorgas, Sanitation in Panama, Appletons.) i. The application of a thin iridescent film of oil to the sur-face of water areas it is not feasible to drain, at least after everyrain. The oil is either sprayed from knapsack sprays, or fedby drip cans. The latter are only adapted to streams or ditchesconveying running water. Crude oil is best (Figs. 74, 75). 3. Stocking swamps and pools with species of fish that arepredatory upon mosquito larvae. The Public Health Serviceis introducing the employment of the top minnow, Gambusiaaffin
Practical preventive medicine . Pig. 74.—Oilers at work in marsh. (Gorgas, Sanitation in Panama, Appletons.) i. The application of a thin iridescent film of oil to the sur-face of water areas it is not feasible to drain, at least after everyrain. The oil is either sprayed from knapsack sprays, or fedby drip cans. The latter are only adapted to streams or ditchesconveying running water. Crude oil is best (Figs. 74, 75). 3. Stocking swamps and pools with species of fish that arepredatory upon mosquito larvae. The Public Health Serviceis introducing the employment of the top minnow, Gambusiaaffinis, for this purpose. 2. The application of solutions having a lethal action on thelarvae, such as the Larvacide of Darling. This is prepared DISEASES TRANSMISSIBLE BY INSECTS [93 from crude carbolic acid of a sp. gr. not greater than andcontaining not less than 30 per cent, tar acids. One hundred. pIG_ 7,^—Burning out ditch with oil spray. (Gorgas, Sanitation in Panama, Appletons.)
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectprevent, bookyear1920
