If bitten by a mosquito, moisten a piece of toilet soap and rub it on the bite. This is the advice given by Dr. L. O. Howard, Chief Entomologist of the United States Department of Agriculture, who has made extensive researches into the habits of the mosquito. Dr. Howard also recommends, as the most effective application for keeping mosquitoes away from one's person, rubbing the hands and face with a mixture of two parts each of oil of Citronella and spirits of camphor with one part of oil of cedar. "A few drops of this mixture on a towel hung over the head of the bed will keep the common house mosquitoes away," says Dr. Howard. "A few drops on the hands and face will keep them away for hours. The evaporation of the mixture may be retarded by mixing it with castor oil or liquid vaseline."

Ridding a house of mosquitoes may be accomplished by catching the individual mosquitoes and by fumigation, provided there is effectual screening and full precautions taken to prevent others from breeding in the house. While some varieties of mosquito, including the yellow fever varieties, bite more freely in the day time than at night, most of them are active only after dark. It is easy to find

quito in the room to insure a good night's rest. If the cup is pressed against the ceiling so as to inclose the mosquito the insect, attempting to fly, will be caught in the kerosene and killed. A mosquito trap used in India consists of a box lined with dark cloth and with a hinged door at one end. This is placed in a dark corner of the room, as mosquitoes always seek a cool, shady place in which to rest. If driven out of all other dark places they will gather during the day in this box which can then be closed and the mosquitoes killed by pouring a teaspoonful of benzine through a hole.

The most effective way of killing all the mosquitoes in a house, however, is by fumigation. Tests made by various experimenters indicate that the ordinary pyrethrum, or "Persian insect powder," if pure and reasonably fresh, is the best fumigant for this purpose. If heaped If heaped up in a cone and lighted at the top, this powder will burn slowly and give out a dense smoke, or it may be moistened and molded into cones which will burn readily after drying with less waste of powder. The smoke stupifies the mosquitoes which must be swept up and burned after the fumigation. It takes about a pound of insect powder for every thousand cubic feet of interior space. Another effective fumigant, known as "Mimms Culicide," is made of equal parts by weight of carbolic acid crystals and gum camphor. The melted crystals are poured slowly over the gum, which is absorbed, and the result is a clear liquid which may be kept some time in tight jars. Three ounces of this Culicide placed over a lamp or other moderate heat, will give off sufficient vapor to kill all the mosquitoes in an ordinary sized room.

Screens for mosquitoes must be absolutely tight and with a mesh of not less than twenty to the inch. A mesh of fifteen to the inch will admit the smaller varieties of house mosquitoes.

There can be no permanent relief from mosquitoes, however, without the destruction of their breeding places, and these breeding places may be any place where water can accumulate and stand for a few days. And it is in the discovery of these

breeding places, rather than in their destruction or sterilization, that the ingenuity of the householder who wishes to free his home from the tiny pests will be most severely taxed. It is comparatively simple to drain a marshy spot in the lawn or garden, or to grasp the fact that a fish-pond or fountain is a good place for mosquitoes to lay their eggs, but it does not occur to the average individual until his attention is sharply drawn to it that there is no body of water too small to furnish a nursery for the infant mosquito. Large broods have been found to be produced from rain water puddles in hoofprints by the roadside. A little used horse-trough is a very common source of mosquitoes. Chicken pans in poultry yards, the water cup standing on the frame of the grindstone, and even the water that accumulates in garden furrows, especially where the soil is clayey, may produce mosquitoes in myriads. Houses that have been carefully searched have still been infested with mosquitoes until the source was found in water pitchers in unused guest rooms. Mosquitoes have been known to breed in flower vases in which the water was not frequently changed. It is customary to attribute the presence of mosquitoes to swamps or ponds in the near neighborhood, but more often the cause will be found in a discarded tomato can in the back yard or in some overlooked receptacle for water in the cellar. Every effort to exterminate the mosquito in one of the large state hospitals failed until, in a dark corner of an unused cellar, the investigators came across a half barrel partly filled with water. In another case the mosquitoes in a house originated in a beer bottle partly filled with water in the cellar, and Dr. Howard reports a veritable plague of mosquitoes that was traced to a case of empty beer bottles allowed to remain in remain in a back yard. Mosquito larvæ have also been known to breed in the holy water fonts in churches, while in one house where every possible breeding place. had been, it was thought, discovered and drained, they were found to originate in the water tank of an acetylene gas gas machine. Fire buckets, fragments

of broken bottles placed on top of stone walls, disused wells, open ditches by the roadside, sewer catch basins, old boxes and cans thrown on the dump heap, unscreened water tanks, rain water barrels and cesspools — in short, any place where half a pint of water or even less is allowed to stand for ten days or more, becomes the mosquito's breeding place. The only The only exception is the aquarium, for gold fish and almost all kinds of fresh water fish eat the young mosquitoes as fast as they are hatched.

Since mosquitoes breed only in standing water their elimination is a matter only of finding the possible breeding places. Once these are found it is perfectly easy to keep mosquitoes down. Every receptacle that can contain water should be emptied and so placed that it will not fill again the next time it rains. If it is a tank or barrel or cistern which must be kept filled, it is easy to fit it with a tight screen cover that will keep out the female mosquito that is looking for a place to lay her eggs. The draining of marshes and useless ponds is usually comparatively easy, but where this is impossible the application to the surface of the water of a very small quantity of kerosene oil will kill all the immature mosquitoes that may be present and keep the adult mosquitoes from depositing their eggs. The oil must be so applied that it will spread over the entire surface of the water. This can be done by pouring small quantities at intervals around the edge or by spraying marshy areas with any kind of a spraying device such as is used in orchards. The oil forms a thin film that prevents the young mosquito from coming to the surface to breathe. If the body of water be a large one a heavy wind will sometimes break the film of oil and in a few sunshiny days much of the oil will evaporate. Frequent attention and a very little kerosene will, however, keep a good-sized farm entirely free from mosquitoes all summer. One ounce of kerosene is sufficient for fifteen square feet of water surface.

The common mosquito requires but ten days for development from the laying of the egg to the final hatching of the fullfledged, biting mosquito. The malaria

mosquito takes about twenty-one days from egg to adult. Water that stands exposed less than ten days, therefore, is not dangerous, but a large brood of mosquitoes may be hatched in a roadside puddle that completely evaporates in two weeks. Very often depressions that hold water temporarily go unnoticed by reason of high grass that surrounds them, and this is frequently the case in city parks, which are the most prolific sources of mosquitoes in most Northern cities.

The common inland mosquito deposits its eggs, 250 to 400 at one time, on the surface of the water at night. The mass of eggs is held firmly together and floats like a small raft. The eggs hatch in from fifteen to twenty hours, producing the larvæ - the "wrigglers" often seen in rain-water barrels and cisterns. When fully grown, which is within a few days, they are about one quarter of an inch long and move through the water with a rapid, jerky motion, coming to the surface to breathe every minute or two. In from eight to ten days the larvæ pass into the pupa stage, in which the head is apparently greatly increased in size. In from two to three days the full-fledged mosquito bursts through the pupa-case and flies away on its quest for blood.

Easily the most annoying of all mosquitoes is the huge striped-legged "Jersey mosquito" of the Atlantic Coast. The first efforts toward eliminating this particular variety were begun in 1905 by Dr. Alvah H. Doty, Health Officer of the Port of New York for many years. Staten Island, in New York Harbor, on which the Quarantine Station is located, is bordered by salt marshes in which innumerable mosquitoes developed and made almost the whole of the beautiful island uninhabitable for persons sensitive to mosquito bites. Doctor Doty's method was that of drainage and oiling. Ditches which drained the marshes on both sides of the island were dug and at frequent intervals kerosene oil was sprinkled over all the undrained or undrainable portions. The result was a real decrease in the number of mosquitoes, and after three years of this work the demand for porch screens on Staten Island began to fall off.

To Doctor Doty must be given the credit for having pointed the way to mosquito extermination. In New Jersey they followed his Staten Island demonstrations so that in the next seven years considerably more than half of the salt marshes had been ditched and drained with a result, according to competent observers, of reducing the annual mosquito output more than 80 per cent.

The method of ditching is simplicity itself. The soft earth of the marshes is as easy to cut as so much butter. Most of the work has been done by Mr. Jesse P. Manahan, of Red Bank, with machines of his own invention: a hand cutter, with which two men can dig 500 feet of ditch, ten inches wide and thirty inches deep, in a day; and a power digger operated by a gasolene engine that can do a mile of the same sized trench in a working day. In the vicinity of Newark and Jersey City, oil has also been used on the marshes at the expense of persons interested in reclaiming the marsh land, but even in sections where only drainage has been used the effect has been almost magical. No exact statistics are available, but thousands of acres of useless marsh land have been reclaimed and now produce a large tonnage per acre of excellent hay, and the only mosquitoes now regarded as a serious menace in Northern New Jersey are those that are found everywhere else in the United States the fresh water varieties. Similar ditching and draining has been undertaken by other states, notably Connecticut and South Carolina, and by many isolated counties and individual land owners in other states. A similar method of draining fresh water swamps has been adopted in several inland

states.

That most of the mosquitoes in cities are developed in the cities themselves has been repeatedly demonstrated. The report for 1911 of the mosquito inspections in Newark, N. J., shows that, in all, 9,777 house-to-house inspections were made in that town. Thirty-five hundred sewer catch basins were oiled once every fifteen days during the summer. The inspectors found 638 rain-water barrels, 125 rain water pools, 49 unused tannery vats,

10 fire tanks, 12 manure pits, 19 cisterns, 28 cellar foundations, and 16 sewer basins on private property, all breeding mosquitoes. And these do not take into account the minor and much more numerous breeding places inside of buildings themselves. All these breeding places, as soon as found, were treated with kerosene. This work was in addition to the city's own share of the ditching and draining of the salt marshes.

A very complete municipal campaign against the malaria mosquito was begun several years ago in the progressive little city of Hartsville, S. C., and has been continued annually ever since. The methods employed in Hartsville may be very easily adapted to the requirements of any community. The board of health first published a circular pointing out the danger of mosquitoes and recommending screening and constant supervision of premises to prevent their breeding. This was placed in the hands of every householder. Then the town council made a survey of the entire city, drained a few low places where rain water was accustomed to accumulate, and inaugurated a system of weekly inspection of all premises and ditches in town, putting kerosene oil regularly upon any water which could not be drained or emptied. They quickly found that most of the mosquitoes were being bred in the back yards, and the importance of preventing water from standing was again emphasized to the individual citizens. Though statistics are not available, Dr. William Egleston, Health Commissioner of Hartsville, reports that malaria, though extremely prevalent up to ten years ago, is now practically a negligible disease, and that constant attention to the work of extermination has made it possible for the inhabitants to sit on their porches on summer evenings without the discomfort of mosquitoes or the expense of screens.

New Orleans is the largest city in the United States in which there has been anything like concentrated community effort at eliminating the mosquito. The object of the New Orleans crusade was to get rid of the yellow fever mosquito, and the results obtained in the Crescent City