19,168. Ellis, G. B., [Chemische Fabrik von Heyden Akt.-Ges.]. Sept. 5. Benzoates ; salicylates.-Colloidal water-soluble salts of heavy metals, such as mercury, silver, iron, copper, and zinc, are obtained by conducting any ordinary wet process for the production of the ordinary insoluble salts in the presence of colloidal organic substances such as albuminous or albuminiform bodies, gums, or their derivatives. For example, a solution of colloidal water-soluble calomel is formed by mixing solutions of mercurous nitrate and sodium chloride in the presence of albuminous bodies. The solution of the colloidal salt may be separated by dialysis, and may then be evaporated to dryness or precipitated with alcohol &c. Otherwise the salt may be precipitated from the original solution by the addition of an acid and then filtered, washed with water, redissolved by neutralizing, and finally re-precipitated by alcohol &c. or by drying the solution. Examples are also given of the preparation by this method of colloidal mercuric or other salicylate from the corresponding chloride and sodium salicylate. Salts of other alkali or alkaline-earth metals may be used instead of the sodium salt mentioned above, and salts of organic acids other than salicylic acid, especially benzoic acids and their derivatives, may be treated.