Fig. 63. Ditching of low area of pool formed by seepage water. Malaria prevailed among tenants in all houses. solves the sticky substance which binds the nits to the hair, and the kerosene kills the lice. Gasoline is as efficient as kerosene, but it should not be used, as its inflammability is much greater than kerosene. The danger of burning a patient in case either of these preparations is employed should be borne in mind, and the patient should be outdoors at the time of application and remain outside until the hair becomes dry. Several applications at intervals of two or three days are required, as the nits, or eggs, are hard to kill. These may sometimes be combed from the hair with a fine-toothed comb. The body louse lives in the clothing, so this should be boiled or baked. If this is impossible the clothing, and especially the seams, should be ironed with a hot iron. An efficient method is to soak the clothing in gasoline, or the vapor of gasoline may be forced through them. Another less expensive method is to put the clothes for half an hour in a soapy solution to which 2 per cent of trichlorethylene has been added. A good application to the body is a solution made by mixing 1 part of gasoline with 3 parts of vaseline. This preparation is noninflammable under working conditions. An ointment made by mixing 5 parts of naphthalene with 95 parts vaseline is also useful for this purpose. Pubic lice, commonly known crabs," are destroyed by the application of white precipitate, or mercurial ointment. as Lenz found that he could eradicate lice from prisoners at Puchheim (near Munchen) by means of finely powdered naphthalene. A handful of this material is put into the patient's clothing, introduced through the opening at the neck. He is made to sleep at night with all his clothes on. The body heat causes the naphthalene to evaporate, the vapor killing not only the lice but also most of the eggs. This treatment should be repeated every 4 days for a period of 12 days. In the British Army a powder composed of naphthalene (96 parts), creosote (2 parts), and iodoform (2 parts) is used. About two-thirds of 1 ounce is required for each man. Two tablespoonsful of an ointment made of crude mineral oil (9 parts), soft soap (5 parts), and water (1 part) is rubbed into the interior seams of the clothing. Articles of underclothing are treated by dipping and wringing them out in a solution of 1 per cent each of naphthalene and sulphur in benzene or gasoline. Itch Mite (Sarcoptes Scabiei). The itch mite is a small parasite which burrows into the skin and produces a disease known as the itch or scabies. The irritation produced by the mite causes scratching, which results in excoriations, papules, and pustules at places where the mite has entered. Prevention.-A person with the itch should be careful not to shake hands with other persons. He should use separate towels and sleep in a bed by himself. He should, as far as possible, keep away from other people, particularly children, as they are especially susceptible to the disease. Treatment. The patient should take a hot bath, using plenty of soap, and an ointment composed of powdered sulphur (2 teaspoonsful) and vaseline (8 tablespoonsful) should then be well rubbed into the skin. The treatment is continued for three nights, and on the morning of the fourth day the patient takes a bath and puts on clean clothing. If there is burning of the skin, a little zinc ointment may be rubbed in. The underwear and bed clothing should be boiled and the outer clothing ironed or baked. The treatment should be repeated after an interval of three or four days if itching is still present. Another method of treatment is to rub the body with powdered sulphur every night for a week after taking a bath and also sprinkle it between the bed sheets at night and on the underwear during the day. The sheets and underwear should be changed each day. Ticks. Ticks are believed to feed upon blood alone. They attach themselves to the skin of man and animals and partly burrow into it. They hold on tenaciously. If carelessly pulled off, the head may be torn from the body and remain in the skin. The eggs of ticks are deposited upon the ground. The larvæ are six-legged creatures which catch hold of any animal within their reach. After becoming engorged with blood the larva drops off and changes to the third or nymph stage. The nymph, after obtaining more blood and shedding its skin, changes to the adult insect. The tick is instrumental in spreading Rocky Mountain spotted fever throughout some parts of the country. It should be removed from the skin by means of hartshorn, kerosene, turpentine, or carbolized vaseline, which prevent the head remaining in the skin. Persons traveling through woods or other places in a tick-infested country should stop and search their bodies every two or three hours and remove any ticks that may have attached themselves thereto. Bedbugs. The presence of bedbugs in dwellings is indicative of want of care and cleanliness as to bed, bedclothes, etc., and means should be taken to exterminate them when they appear. A liberal application of kerosene oil to the places infested is probably the best means of killing them. There are preparations of gasoline or naphtha sold which leave no stain when sprayed on painted or papered walls, |