PURIFYING WATER

If an emulsion of clay is poured into a soap solution, the clay gradually separates out without clarifying the liquid. When a few drops of hydrochloric acid, how ever, are added to a soap solution and a small quantity about 1.5 percent of a clay emulsion poured in, the liquid clarifies at once, with formation of a plentiful sediment. Exactly the same process takes place when the waste waters from the combing process in spinning are treated with clay. The waters which remain turbid for several days contain 500 to 800 grams of fatty substances per cubic meter. If to 1 liter of this liquid 1 gram of clay is added, with 15 to 20 percent of water, the liquid clarifies with separation sediment and assumes a of a golden-brown color. Besides the fatty substances, deposit also contains a certain of nitrogenous bodies. Dried at (100⁰C) this quantity 212⁰ F., it weighs about 1.6 grams and contains 30 per cent of fat. The grease obtained from it is clear, of good quality, and deliquesces at 95⁰ F. After removal of this fat, the mass still contains 1.19 per cent of nitrogen.