It should be frequently removed. It should be utilized in the garden or field by being placed under a thin layer of soil. To excreta from the sick, milk of lime or unslacked lime should be added before disposal in the soil. [Illustration: Fig. 5.--Self-acting peat dust closet. The lid is replaced by a hinged reservoir containing the peat dust. Whenever this is let down a certain quantity of peat dust is discharged automatically and thrown, upon the night soil. (From Weyl's Handbuch der Hygiene. II, p. 315.)] _The water-closet._--There can be no doubt that to-day the water-carriage system, as it is called, or, in simpler language, the indoor water-closet, is preferred to all other contrivances. This is true for the open country as well as for villages and the suburban territories of cities. There is much to be said in favor of the present-day perfect contrivance for the rapid removal of excreta and the exposure thereby prevented. But for all rural inhabitants the cost should be carefully weighed before a water-carriage system is introduced into a house, for none but the best will answer, as all others are likely to become nuisances. The supply of water must be sufficient to flush the water-closet thoroughly and keep all the pipes clean; the plumbing must conform to that in vogue in cities, with its traps and ventilating pipes to prevent the odors of the pipes from escaping into the house; and the disposal of the large quantity of liquid sewage, the most difficult problem, must be properly attended to or it is likely to prove more dangerous to the water-supply than the old dry privy pits. LIQUID SEWAGE. The methods available to dispose of liquid sewage in the country are water-tight cesspools and irrigation. _Vaults._--Water-tight cesspools should be constructed of hard-burned brick, laid in cement, and having a similar brick or a concreted bottom. The inside and outside surfaces of the brick wall should be coated with a thin layer of cement, and clay rammed in around the wall, to increase its imperviousness to water. It should be vaulted above, and topped by a square or round central opening, covered with stone or iron plate. Cesspools are also made of cast or wrought iron, the joints being made water-tight. Cesspools must be ventilated by two pipes, one rising several feet above ground, the other carried to the roof of the house, barn, or other structure near by. The current will, in most cases, tend down the short and up the long pipe. The latter may be dispensed with and the soil pipe of the house act as a flue, provided all branches are perfectly trapped. [Illustration: Fig. 6.--Settling chamber and flush tank for surface and subsurface irrigation of sewage. (From Gerhard's "The Disposal of Household Wastes," 1890.)]