In place of the movable earth closets, a water-tight, concreted area may be built in an annex to the house, which is to receive the night soil from a closet on the floor above with the necessary quantity of dry soil (see fig. 4). Poore, from whose book the illustration is taken, recommends, in addition, the construction of the floor of such a pit with an inclination sufficient to carry away the urine into some gutter outside filled with absorbent soil. The area should have suitable openings for inspection and for removal of contents, as well as for ventilation. Waring recommended a similar system many years ago. The closet described by him discharges into a water-tight vault in the cellar, which requires emptying only occasionally. The contents remain inoffensive, provided sufficient thoroughly dry earth is used. [Illustration: Fig. 4.--Earth closet and dry catch (from Poore's "Rural hygiene," scale, 1/2 inch equals 1 foot). To prevent drafts the earth closet is closed below by a hinged flap which opens and shuts automatically by means of a counterpoise. The catch below is provided with air bricks and an air shaft leading to a ventilator.] In cold climates, indoor closets are especially desirable to obviate the exposure which can not be avoided when closets are out of doors. For invalids there should be a carefully managed earth closet kept in a well-aired room set apart for this purpose. In warm climates, earth closets should be frequently cleaned. To prevent the attraction of flies and insects and the too rapid decomposition of the contents a little unslacked lime added with the earth to the excrement will be of value. The discharges of persons suffering from typhoid-fever and bowel troubles should be mixed with thin slacked lime[1] (milk of lime). One-half to one hour after the mixing, such discharges may be put upon the soil, always at some distance from a well or spring, a stream, or a field under cultivation. [1] Lime, to be used for disinfection, should not be air-slacked, but kept in tightly covered receptacles to prevent this from taking place. In Europe, the use of earth and ashes has been superseded by peat dust. The upper layer of peat is dried in the air and ground in a suitable machine. The coarser particles are removed by sifting and used for bedding in stables. The fine portion, which has a very high absorbing power for fluids and is also capable of preventing odors, is used in dry closets. In Germany there are at present about thirty factories engaged in the preparation of peat moss for the purposes mentioned. Its great advantages over dry earth should bring it into use in our country. (See fig. 5.) It does not matter from a sanitary standpoint which one of the dry-earth systems is adopted, provided the necessary attention be given to it. Every system which can be recommended is bad if not properly attended to. The conditions to be observed are: The night soil should be received in water-tight receptacles.