249,884. Soc. of Chemical industry in Basle. March 28, 1925, [Convention date]. Azo dyes, copper and chromium compounds of. -Azo dyestuffs containing copper or chromium are obtained by treating with an agent yielding copper or chromium an o-oxyazo-dyestuff produced either bv coupling a diazotized polysulphonic acid derived from 2-amino-1-oxynaphthalene-8-sulphonic acid with a coupling component, or by coupling a further sulphonated 1 : 8-oxynaphthalene sulphonic acid with an o-oxydiazo compound; in the latter case, in respect of the treatment with an agent yielding copper, the invention is limited to the treatment of those dyestuffs in which the o-oxydiazo compound is of the naphthalene series. The products dye animal fibres in an acid bath in fast, pure tints; those containing one or more carboxyl groups are suitable for chrome printing on cotton. In an example, the dyestuff from diazotized 2-amino-1- oxynaphthalene-4 : 8-disulphonic acid and 1- phenyl-3-methyl-5-pyrazolone is treated with copper sulphate, the, product dyes wool in red tints. Analogous dyes are obtained from the 3 : 8-disulphonic acid, and by replacing the phenylmethylpyrazolone by other pyrazolones or by a compound having a reactive methylene group, e.g. barbituric acid. The corresponding chromium compounds dye wool in blue-red tints, fast to fulling. In another example, the dyestuff from diazotized 2- amino-1-oxynaphthalene-4 : 8-disulphonic acid and 1-oxynaphthalene-4 : 8-disulphonic acid is treated with copper sulphate to yield the copper compound, which dyes wool in fast violet shades. In further examples, the dyestuffs from diazotized 2-amino-1-oxynaphthalene-4 : 8-disulphonic acid and #-naphthol or 1-oxynaphthalene-3 : 8-disulphonic acid are converted into the chromium compounds by treating with alkaline chromite solution or chromium fluoride; the products dye wool in blue tints. Similar dyestuffs are obtained by using the 4 : 8-disulphonic acid for the diazo compound, and a-naphthol or another naphthol-sulphonic acid as the coupling component. If 2-oxynaphthalene-3-carboxylic acid or 3-oxynaphthalene-1 : 8-dicarboxylic acid is used as the coupling component, the resulting dyestuff gives a fast blue tint in chrome printing on cotton ; that from resorcyclic acid gives a violet tint. In another example, the dyestuff from diazotized 4-nitro-2-amino-1-phenol and 1-oxynaphthalene- 4 : 8-disulphonic acid is converted into the chromium compound by treating with chromium fluoride. The product, and the corresponding dyestuffs with 1-oxynaphthalene-3 : 8-disulphonic acid and 1-oxynaphthalene-3 : 6 : 8-trisulphonic acid as components, give bordeaux tints. The compounds from diazotized 4-chlor-2-amino-1- phenol and 1-oxynaphthalene-3 : 8 (or 4: 8)-disulphonic acid are also described. In a further example, the dyestuff from diazotized picramic acid and 1-oxynaphthalene-4 : 8-disulphonic acid is converted into the chromium compound by treating with chromium fluoride: the product dyes wool a fast black. Specifications 26460/12, 1611/15, 15456/15, 104,045, and 226,797 are referred to. 2-Amino-1-oxynaphthalene-3 : 8- and 4 : 8- disulphonic acids are made by coupling 1-oxynaphthalene-3 : 8- or 4 : 8-disulphonic acids with diazobenzene and reducing the products. In the Specification as open to inspection under Sect. 91 (3) (a) the treatment with agents yielding copper is extended to the dyestuffs obtained by coupling further sulphonated 1 : 8-oxynaphthalene sulphonic acids with o-oxydiazo compounds in general, and is not limited to those in which the o-oxydiazo compounds are of the naphthalene series. Chromium acetate, formate and hydroxyhydrate. are also specified as agents yielding chromium, and the chromium compound of the dyestuff from diazotized 1-oxybenzene-2-amino-4- sulpho-6-carboxylic acid and 1-oxynaphthalene- 4 : 8-disulphonic acid is described. This subjectmatter does not appear in the Specification as accepted.