pere per square decimeter is passed until the layer of rubber on the anode is as thick as desired. If more than one such rubber tube is to be deposited from the same latex, it is necessary to use a cheese cloth screen, cylindrical in shape and standing perhaps one centimeter away from the cathode all around, and, like the latter, projecting above the level of the latex. This is to keep the hydrogen evolved at the cathode away from the rubber deposit. Such a screen should have a frame made of insulating material. If nothing else is available, well-insulated, heavy-gage wire will do. The rubber deposit will be milk-colored and will contain about fifty per cent of water. It will be surprisingly tough, but not strong enough to remove from the metal tube without distortion or breaking. If the deposit is fairly heavy (perhaps two millimeters thick when wet) it may be dried on the metal tube, then dusted with talc, and stripped off by being pulled back over itself. It will become nearly transparent when dry, and the surface will be sticky until i t is dusted. Such a dry tube may be vulcanized by immersing i t for one-half to one minute in a two per cent solution of sulfur monochloride in carbon tetrachloride. Latex as it comes on the market carries from one to two per cent of ammonia. This must be removed, best by blowing air over the stirred surface of the latex, until there is a just discernible odor of ammonia left. The only importers of latex a t present are The General Rubber Company, a subsidiary of the United States Rubber Company of New York, and Vultex Corporation of America in Cambridge, Massachusetts.
Triethanolamine. A product has just been made available to industry that is roughly intermediate in its chemical composition and general properties between ardinary alcohol and ammonia. This is triethanolamine. Like alcohol, i t dissolves many substances not soluble in water. Like ammonia, it combines with fatty acids to form soaps. Its chief uses depend on its hygroscopicity and penetrating properties, and thc solubility and the detergent and emulsifying properties of its soaps. As a penetrant i t has been found to permit better application of stains, pigments, and inks upon cellulose materials, such as paper and fabrics. I t is useful as a peptizing agent, t o prepare dispersions of shellac, casein, and rubber. As a plasticizing agent, it has been successfully used with paper, glues, and rubber. As a free base, it neutralizes excess acidity in oily materials. The stearate soap of triethanolamine, because of the very low alkalinity of its water solutions, is expected to prove valuable in cosmetics when it is sufficiently purified. Through its use it is possible to prepare creams and emulsions of fine texture and readily washed by water. The oleate soap of triethanolamine is completely soluble in drycleaning solvents. This property makes it useful in dry-cleaning soaps and textilescouring soaps. I t is useful in preparing emulsions for stuffing leather and coating fabrics. Such emulsions are characterized by stability and low alkalinity. In general, emulsions of oils, solvents and waxes may be easily prepared, using a low concentration of a triethanolamine soap.-Ind. Bull., Arthur D. Little, Inc., No. 33 (Sept., 1929).
