Culicide is made of equal parts by weight of carbolic acid crystals and gum camphor. Melt the acid crystals over a gentle heat, and pour slowly over the gum. The acid dissolves the camphor, and makes a clear, somewhat volatile liquid, with rather an agreeable odor. This solution is permanent, and may be kept indefinitely in tight jars. Use three ounces of this culicide for every 1000 cubic feet of space, and volatilize over a lamp of some kind. A simple and inexpensive apparatus for this purpose (J. B. Smith) consists of an 8-inch section of galvanized-iron stove-pipe, cut so as to leave three legs, and with a series of 1/4-inch holes near the top to make an outlet for the draft. Upon this place a shallow, flat-bottomed basin to hold the culicide, and beneath this use an ordinary glass or other alcohol lamp. Two ounces of culicide may be evaporated with 1/2 an ounce of alcohol in twenty-five minutes, and a larger quantity would probably require proportionately less time if given a larger evaporating surface in a dish of larger diameter than the pipe. This combination is inflammable, but not explosive, and should be used on a cement, earth, or stone floor, or on bricks in a tub of water, to avoid danger of fire. The fumes are not dangerous to human life until they become very dense, and such as might penetrate into upper rooms through leaky floors or doors would do no harm to anything. This also should be allowed to act at least two hours before the doors are opened again. Flies and other insects succumb as readily as mosquitoes.
Pools of rain water, duck ponds, ice ponds, and temporary accumulations due to building; marshes, both of salt and fresh water, and roadPESTS AND NUISANCES side drains; pots, kettles, tubs, springs, barrels of water, and other back-yard collections should be drained, filled with earth, or emptied.
Running streams should have their margins carefully cleaned and covered with gravel to prevent weeds and grass at the water's edge.
Lily ponds and fountain pools should, if possible, be abolished; if not, the margins should be cemented or carefully graveled, a good stock of minnows put in the water, and green slime (algae) regularly cleaned out, as it collects.
Where tanks, cisterns, wells, or springs must be had to supply water, the openings to them should be closely covered with wire gauze (galvanized to prevent rusting), not the smallest aperture being left.
When neither drainage nor covering is practicable, the surface of the standing water should be covered with a film of light fuel oil (or kerosene) which chokes and kills the larvae. The oil may be poured on with a can or from a sprinkler. It will spread itself. One ounce of oil is sufficient to cover fifteen square feet of water. The oil should be renewed once a week during warm weather.
Particular attention should be paid to cesspools. These pools, when uncovered, breed mosquitoes in vast numbers; if not tightly closed by a cemented top, or by wire gauze, they should be treated once a week with an excess of kerosene or light fuel oil.
Certain simple precautions suffice to protect persons living in malarial districts from infection: —
First: Proper screening of the house to prevent the entrance of the mosquitoes (after careful search for and destruction of all those already present in the house), and screening of the bed at night. The chief danger of infection is at night (the anopheles bite mostly at this time).
Second: The screening of persons in malarial districts who are suffering from malarial fever, so that mosquitoes may not bite them and thus become infected.
Third: The administration of quinine in full doses to malarial patients to destroy the malarial organisms in the blood.
Fourth: The destruction of mosquitoes by one or more of the methods already described. These measures, if properly carried out, will greatly restrict the prevalence of the disease, and will prevent the occurrence of new malarial infections.
It must be remembered that when a person is once infected, the organisms may remain in the body for many years, producing from time to time relapses of the fever.
A case of malarial infection in a house (whether the person is actively ill or the infection is latent) in a locality where anopheles mosquitoes are present, is a constant source of danger, not only to the inmates of the house, but to the immediate neighborhood, if proper precautions are not taken. It should be noted in this connection that the mosquitoes may remain in a house through an entire winter, and probably infect the inmates in the spring upon the return of the warm weather.