CHEMICAL CLOSET
Fig. 11.—A primitive vault privy in Massachusetts. Note the tight, shallow, easily cleaned vault. A, Brick vault 5 by 6 feet, bottom about 1 foot in the ground; B, water-tight plastering; C, rowlock course of brick; D, door hinged at top; E, door button; F, three-pane window hinged at top; G, passageway
A type of sanitary privy in which the excrements are received directly into a water-tight receptacle containing chemical disinfectant is meeting with considerable favor for camps, parks, rural cottages, schools, hotels, and railway stations. These chemical closets,[4] as they are called, are made in different forms and are known by various trade names. In the simplest form a sheet-metal receptacle is concealed in a small metal or wooden cabinet, and the closet is operated usually in much the same manner as the ordinary pail privy. These closets are very simple and compact, of good appearance, and easy to install or move from place to place. In another type, known as the chemical tank closet, the receptacle is a steel tank fixed in position underground or in a basement. The tank has a capacity of about 125 gallons per seat, is provided with a hand-operated agitator to secure thorough mixing of the chemical and the excretions, and the contents are bailed, pumped, or drained out from time to time.
[4] Among publications on chemical closets are the following: "Chemical closets," Reprint No. 404 from the Public Health Reports, U. S. Public Health Service, June 29, 1917, pp. 1017-1020: "The chemical closet," Engineering Bulletin No. 5, Mich. State Board of Health, October, 1916; Health Bulletin, Va. Department of Health, March, 1917, PP. 214-219.
Chemical closets, like every form of privy, should be well installed, cleanly operated, and frequently emptied, and the wastes should receive safe burial. With the exception of frequency of emptying, the same can be said of chemical tank closets. With both forms of closet thorough ventilation or draft is essential, and this is obtained usually by connecting the closet vent pipe to a chimney flue or extending it well above the ridgepole of the building. The contents of the container should always be submerged and very low temperatures guarded against.
Fig. 12.—Two-seat vault privy
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As to the germicidal results obtained in chemical closets, few data are available. A disinfecting compound may not sterilize more than a thin surface layer of the solid matter deposited. Experiments by Dr. Alvah H. Doty with various agents recommended and widely used for the bedside sterilization of feces showed "that at the end of 20 hours of exposure to the disinfectant but one-eighth of an inch of the fecal mass was disinfected."[5] Plainly, then, to destroy all bacterial and parasitic life in chemical closets three things are necessary: (1) A very powerful agent; (2) permeation of the fecal mass by the agent; (3) retention of its strength and potency until permeation is complete. The compounds or mixtures commonly used in chemical closets are of two general kinds: First, those in which some coal-tar product or other oily disinfectant is used to destroy germs and deodorize, leaving the solids little changed in form; second, those of the caustic class that dissolve the solids, which, if of sufficient strength and permeating every portion, should destroy most if not all bacterial life. Not infrequently the chemical solution is intended to accomplish disinfection, deodorization, and reduction to a liquid or semiliquid state. Ordinary caustic soda, costing about $1 in 10-pound pails, has given good results.
[5] Annual Report, Mass. State Board of Health, 1914, p. 727.
A simple type of chemical closet is shown in [Figure 14], and the essential features are indicated in the notation. These closets with vent pipe and appurtenances, ready for setting up, retail for $20 and upward. A chemical tank closet, retailing for about $80 per seat, is shown in [Figure 15].
The Department of Agriculture occasionally receives complaints from people who have installed chemical closets, usually on the score of odors or the cost of chemicals.
Fig. 13.—Two-seat-vault privy. Note the shallow, water-tight, easily cleaned concrete vault
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