Germicidal detergent or cosmetic compositions are made by mixing soap or similar saponaceous substances or compositions containing them with an aromatic mercury salt in which one bond of the mercury atom is directly linked with a nuclear carbon atom of an aromatic hydrocarbon and the other bond is connected to an acid radical, and the nuclear or side chain carbon atoms are not directly connected with any element other than carbon, hydrogen or mercury. The following phenyl mercuric salts are specified: nitrate, lactate, glycollate, acetate, benzoate, salicylate, recinoleate, gluconate, tartrate, citrate, adipate, sebacate, azelate, laevulinate, succinate, saccharate, malate, fumarate, maleate, arsenate and arsanilate. The corresponding compounds of polycyclic hydrocarbons may be used. These compounds may be incorporated with soap in bar, flake, powder or liquid form, with shampoo liquids, tooth paste, shaving creams, or cosmetics. The soaps used include alkali metal salts of fatty acids, abietic acid (from rosin), fatty acids obtained from the oxidation of petroleum hydrocarbons and also the sodium salts of sulphonated higher fatty alcohols and similar substances. The compounds sold under the Registered Trade Marks "Gardinol" and "Igepon" are referred to. Dyes and perfumes may be added. The Specification as open to inspection under Sect. 91 describes also germicidal compositions made by mixing the aromatic mercury salts with substances which are in a highly dispersed state in a liquid medium or capable of being so dispersed. Such substances are natural gums such as tragacanth, or gum arabic, agar-agar, gelatin, starch, dextrin, dispersions of lanolin or other fat, or of clays and silicates, and also soaps. In addition to the above soaps and saponaceous substances, the following substances are specified:--sodium salts of sulphonated cycloaliphatic alcohols, glycols or glycerols; amino compounds of high molecular aliphatic and aromatic compounds such as duodecylamine, duodecylethyldiamine; condensation products of aliphatic or hydroaromatic sulphonic acids or their esters, amides or halides with higher aliphatic acids or derivatives thereof; or any of the above compounds in which sulphuric acid is replaced by phosphoric or other dibasic acid. Other germicides such as hexyl resorcinol, iodine chlorthymol, cresylic acid or chloramine T may be added. An example of tooth paste is given consisting of:--calcium carbonate, calcium glycuronate, glycerol, water, gum, tragacanth, flavouring and phenyl mercuric salicylate. Perfume, colour and a sweetening agent such as saccharine may be added. Calcium carbonate may be replaced by calcium phosphate or magnesia. This subject-matter does not appear in the Specification as accepted.ALSO:Germicidal detergent or cosmetic compositions are made by mixing soap or similar saponaceous substances or compositions containing them with an aromatic mercury salt in which one bond of the mercury atom is directly linked with a nuclear carbon atom of an aromatic hydrocarbon and the other bond is connected with an acid-radical, and the nuclear or side chain carbon atoms are not directly connected to any element other than carbon, hydrogen or mercury. The following phenyl mercuric salts are specified: nitrate, lactate, glycollate, acetate, benzoate, salicylate, ricinoleate, gluconate, tartrate, citrate, adipate, sebacate, azelate, laevulinate, succinate, saccharate, malate, fumarate, maleate, arsenate and arsanilate. The corresponding compounds of polycyclic hydrocarbons may be used. These compounds may be incorporated with soap in bar, flake, powder or liquid form, with shampoo liquids, tooth paste, shaving cream, or cosmetics. The soaps used include alkali metal salts of fatty acids, abietic acid (from rosin), fatty acids obtained from the oxidation of petroleum hydrocarbons, and also the sodium salts of sulphonated higher fatty alcohols, and similar substances. The compounds sold under the Registered Trade Marks "Gardinol" and "Igepon" are referred to. Dyes and perfumes may be added. The Specification as open to inspection under Sect. 91 describes also germicidal compositions made by mixing the aromatic mercury salts with substances which are in a highly dispersed state in a liquid medium or capable of being so dispersed. Such substances are natural gums such as tragacanth or gum arabic, agar-agar, gelatin, starch, dextrin, dispersions of lanolin or other fat, or of clays and silicates, and also soaps. In addition to the above soaps and saponaceous compositions the following substances are specified : sodium salts of sulphonated cycloaliphatic alcohols, glycols or glycerols ; amino compounds of high molecular aliphatic and aromatic compounds such as duodecylamine and duodecyl ethyl-diamine; condensation products of aliphatic or hydromatic sulphonic acids or their esters, amides or halides with higher aliphatic acids or derivatives thereof; or any of the above compounds in which sulphuric acid is replaced by phosphoric or other dibasic acid. Other germicides such as hexyl resorcinol, chlor-thymol, iodine, cresylic acid or chloramine T may be added. An example of tooth paste is given consisting of: calcium carbonate, calcium glucuronate, glycerol, water, gum tragacanth, flavouring and phenyl mercuric salicylate. Perfume, colour and a sweetening agent such as saccharine may be added. Calcium carbonate may be replaced by calcium phosphate or magnesia. This subject-matter does not appear in the Specification as accepted.