c. Charcoal. The powerfully deodorising properties of charcoal obviously adapt it for the removal of excreta in the dry state, after the admixture with them. But the comparatively high price of animal charcoal, although nearly six times the value of dry earth as a deodorant, prohibits its being extensively used. Peat is, however, cheaper than animal charcoal. To obviate the objection of cost, Mr Stanford, in 1872, proposed to make charcoal for this purpose from seaweed. The charcoal obtained from this source is said to be cheap and of great service as an excretal deodoriser. The mixed charcoal and sewage is sufficiently odourless to be stored for some months in a convenient receptacle outside a dwelling-house.
After the seaweed charcoal has become thoroughly impregnated with fæces and urine, the mixture is recarbonised in a retort, and the carbon can be again used; the distilled products (ammoniacal liquor, containing acetate of lime, tar, and gas) are sufficient to pay the cost, and it is said even to yield a profit.[158]
[158] About the same time carbonisation of sewage in retorts, with or without previous admixture with charcoal, was proposed by Mr Hickey, of Darjeeling. There can be little doubt that, regarded in a purely sanitary point of view, carbonisation of sewage matter is an excellent plan. Mr Hickey proposed the utilisation of the ammoniacal products resulting from his process.
d. Dried earth. The Rev. Mr Moule was the first to direct attention to the value of dried earth as a deodorant of excreta.
Mr Moule’s ‘earth closet’ consists of a box with a receptacle below for the excreta. By pulling a plug dried earth, which is placed in a hopper above, enters the closet and falls upon the excreta, thus disinfecting and deodorising it. The consumption of earth averages from 11⁄4 to 11⁄2 lb. a day. The slop water should not be thrown into the closet, but disposed of in some other way. In another plan, as in Taylor’s improved closet, the urine is carried off without mixing at all with the fæces.
Clay, marl, and vegetable humus form the best kind of earths. When dried the clay may be easily reduced to powder. Chalk and sand are comparatively useless. The receptacle is emptied from time to time, the contents forming a valuable manure.
The earth closet is more particularly adapted for small villages and isolated mansions. One difficulty of its application by cottagers consists in the necessity of collecting,
drying, and storing the earth; the cottager’s mostly limited space in his dwelling not permitting this. One great obstacle to the effective carrying out of this system amongst extensive communities is the difficulty of procuring the large supply of earth that its adoption necessitates. With proper supervision and care the ‘earth system’ answers admirably; but if these are not bestowed on it, it as signally fails. It has been adopted with great success in many schools, barracks, and other large buildings.
“It is coming into great use in India, and is carried out with great attention to detail. In those European stations where water is not procurable Mr Moule’s invention has been a boon of great value, and medical officers say that nothing has been done in India of late years which has contributed so much to the health and comfort of the men. The plan of separating the urine from the fæces has been strongly advocated by Dr Cornish, of Madras, and would, no doubt, be attended with great advantages in India if there are means of disposal of the urine. The chief difficulty in the European barracks in India is felt during the rainy season, when the mixed excreta and earth cannot be kept sufficiently dry. In the case of natives of India, however, a serious difficulty arises in the use of the earth system, in consequence of the universal use of water for ablution after using the closet. Every native takes with him a small vessel holding ten to twenty ounces of water, so that a large amount of fluid has to be disposed of. The usual earth closet does not suffice for this. Mr Charles Turner, C.E., of Southampton, has contrived a closet suitable for the native family; it is unfortunately too costly, and possibly a simple iron box, with a pipe to carry off the urine and ablution water, would be better suited for the poorer classes.”[159]
[159] Parkes.