Acid wool dyes, dyeing with.--The dyeing of animal fibres with dyes, containing one or more sulpho groups but no metal in complex combination, that dye in an acetic acid bath, is facilitated by adding to such a dyebath, an amount not exceeding 0,5 per cent of the weight of the goods to be dyed, a soluble salt of an organic water-insoluble nitrogenous base or of a quaternary ammonium compound, which base or compound contains at least one aliphatic or cycloaliphatic residue containing at least 8 carbon atoms but contains no polyethenoxy group. A preparation for addition to the dye-bath may contain the dyestuff together with the soluble salt in an amount not exceeding 5 per cent of the weight of the dyestuff. Specified soluble salts are the trimethylammonium-sulphomethylate of monostearoyl- or monooleyl - p - phenylenediamine or of monostearoyl-or monooleyl-ethylenediamine the hydrochloride of diethylcetylamine, dimethyloctodecylamine or pentadecyldihydroimidazole, octodecyltri-methylammonium sulphomethylate, cetylpyridinium chloride or bromide, the salts of unsulphonated cyclic amidines and their quaternary ammonium compounds as described in Specifications 403,977 and 419,010, the mixed ether of cetyl alcohol and N-oxymethylpyridinium chloride, the soluble salts of the stearic acid ester of dimethyl- or diethyl-aminoethanol, stearylcholine hydrochloride or the corresponding benzyl compound, the palmitic acid ester of 1 - oxyphenyl - 3 - trimethylammonium chloride, the stearic acid ester of oxyethyl-pyridinium chloride, the hydrochloride of diethylaminoethyloctodecyl carbonate, the stearic acid ester of the addition product from pyridine and glycerolmonochlorhydrin or a : a <1> glyceroldichlorhydrin, the corresponding compounds in which the stearic or palmitic acid residue is replaced by the residue of oleic, capric, lauric, myristic or ricinoleic acid or the cetyl alcoholic residue is replaced by that of oleyl or other higher alcohols; similar derivatives of diethylenetriamine or of triethylenetetramine may also be used. Specified dyestuffs, additional to those of the examples below, are Benzyl bordeaux B, Bordeaux B, Neutral blue R, Neutral blue B, Blue black N, Acid black HA, Acid black green G, Palatine black A, Cloth fast blue R, Naphthylamine black V, Jet black R, Cloth fast black BN, Nerol B, Biebrich patent black 4AN, Cloth fast black B, Acid black D, Naphthol black 6B and those dyeing in an acetic acid bath described in Specifications 25866/12, 30055/13, 114,339, and 211,742, [all in Class 2 (iii)]. The following examples are specified: (1) 10 Parts of wool are entered into a bath at 60 DEG C. containing sodium sulphate, acetic acid, 0.5 part of the dyestuff 1-naphthyl-amine --> 1 - naphthol - 3 : 6 - disulphonic acid, and 0.01 part of the trimethylammonium-sulphomethylate of monostearoylethylenediamine, the bath is heated during 1 hour to boiling and further boiled for 1 hour to obtain a pure deep red dyeing. (2) 10 Parts of wool are entered into a bath at 60 DEG C. containing sodium sulphate, acetic acid, 0.05 part of the dyestuff obtainable by condensing benzaldehyde (1 mol.) with ethylbenzylaniline (2 mols.), sulphonating and oxidizing and reacting the product with p-phenetidine, and 0.01 part of the product of reaction of m -heptadecylbenzimidazole with glycerol chlorhydrin, the bath is heated during \ba1/2\be hour to boiling and further boiled for 1 hour to obtain a vivid deep blue dyeing; the dyestuff may be replaced by the disulphonic acid of sym-1 : 4-di(4<1> : 4<11>-dimethyl) phenylaminoanthraquinone (green) or the 2 : 7-disulphonic acid of 3 : 6-diphenyl naphthophenosafranine (blue). (3) 100 Parts of a mixture of the dyestuffs, 4-nitraniline --> (acid) 1 : 8 : 3 : 6 - aminonaphtholsulphonic acid (alkaline) \sM aniline, Orange II and Benzyl bordeaux B are stirred at 100 DEG C. and 20 parts of a 10 per cent alcoholic solution of the mixture of hydrochlorides of N-dioxypropylimidazoles, obtainable by treating with glycerol chlorhydrin the benzimidazole product from o-phenylenediamine and hydrogenated fish oil, is sprayed on to the mixture. (4) 100 Parts of the dyestuff, 1 : 8 : 3 : 6-aminonaphthol-sulphonic acid --> 1-phenylaminonaphthalene-8-sulphonic acid, are pasted with alcohol and mixed with 15 parts of an alcoholic solution containing phosphoric acid and 10 per cent of the mixture of the hydrochlorides of N-dioxy-propylimidazoles referred to in (3) and the mixture is dried; the products of (3) and (4) with or without addition of a dispersing agent are suitable for incorporation in a bath for dyeing wool according to standard practice. (5) 10 Parts of wetted wool are entered into a bath at 60 DEG C. containing acetic acid, 0.4 part of Acid black green G and 0.01--0.015 part of the mixture of N-oxyalkylated imidazoles obtainable by treating with glycerol chlorhydrin and ethylene chlorhydrin the imidazole product from o-phenylenediamine and coconut oil, the bath is heated during \ba3/4\be hour and further boiled for 1 hour whereupon sulphuric acid is added and the boiling continued for 20 minutes to obtain a deep black dyeing. Specifications 306,116, [Class 2 (iii)], 364,104, 372,325, 436,790, and 436,863 also are referred to. The Specification as open to inspection under Sect. 91 comprises also the use of the soluble salts of the base or quaternary ammonium compounds in printing. This subject-matter does not appear in the Specification as accepted.