New acid dyestuffs and intermediate products of the benzene and naphthalene series are obtained by introducing into a primary or secondary amino-group of such dyestuffs or intermediates the alcoholic sulphuric acid group -R-SO4H (R=alkylene); the group -SO4H is termed the sulphato group. The new products which may also contain sulphonic groups may be obtained by the following alternative methods:-(1) The dyestuffs, or their leuco compounds, or intermediate products may be treated with chlorhydrins such as ethylene, propylene, butylene, or glycerol chlorhydrins, and the resulting N-oxyalkylated bodies treated with sulphuric acid or other agent which will convert an alcohol into an alkyl hydrogen sulphate; instead of chlorhydrins, bromhydrins may be used. (2) The dyestuffs or intermediate products may be treated with a chloralkylhydrogen sulphate, for example, chlorethylhydrogen sulphate. (3) The dyestuffs may be built up from components containing sulphatoalkyl groups. (4) N-oxyalkylated dyestuffs may be built up from components containing N-oxyalkyl groups and treated with sulphuric acid. (5) The conversion of the oxyalkyl group into the sulphatoalkyl group can be effected at an intermediate stage, for example, by treating an oxyalkylated leuco compound with sulphuric acid. (6) Dyestuffs may be built up from components containing both oxyalkyl and sulphatoalkyl groups and the former converted into sulphatoalkyl groups by treatment with sulphuric acid. The following oxyalkylated amines and dyestuffs are mentioned as suitable for conversion into sulphato acids:-oxyethylaniline, dioxydiethylaniline, oxyethylethyl (or methyl) aniline, oxyethyl - o - toluidine, oxyethyl - benzylaniline, oxyethyl-a or b -naphthylamine, oxyethyl-o-, m-, or p-diamines, oxyethyl aminophenols and aminonaphthols; azo-dyestuffs prepared from oxyalkylamino compounds; triphenylmethane dyestuffs prepared from oxyalkylamino bodies by condensation with formaldehyde, benzaldehyde or substituted benzaldehydes; oxyethylated azines, oxazines and thiazines. Specifications 11930/09 and 26336/10 are referred to. Sulphatoalkylamines. - Sulphato ethylaniline C6H5.NH (C2H5.SO4H) is obtained by treating oxyethylaniline with concentrated sulphuric acid or chlorsulphonic acid (or aniline with chlorethyl-hydrogen sulphate); the isolation of the calcium and sodium salts is described; the acid product may however be neutralized with soda and the solution used directly for further condensations; disulphato-diethylaniline, sulphatoethylo-toluidine and sulphatoalkyl derivatives of other amines, diamines &c. are similarly obtained. Azo dyes are obtained from the following pairs of components:-aniline and disulphato-diethylaniline, sulphanilic acid and sulphatoethyl-o-toluidine, p-nitraniline and disulphato-diethylaniline, a-naphthylamine and disulphato-diethylaniline (or dioxydiethylaniline followed by sulphation), naphthionic acid and disulphato-diethylaniline, asym-disulphato-diethyl-p-phenylene diamine and b -naphthol, tolidine and 2 mols. disulphato-diethylaniline, p-nitraniline and dioxypropylaniline followed by treatment with sulphuric acid, aniline and disulphatopropylaniline (obtained by treating dioxypropyl aniline with chlorsulphonic acid); these azo dyes dye wool yellow, orange, scarlet, maroon &c. shades from an acid bath. Tri-arylmethane derivatives.-The following examples of the production of triarylmethane dyestuffs containing sulphato-alkyl groups are given; they dye wool yellowish green, bluish green, sky blue, violet, reddish violet &c. shades from an acid bath, in some cases with the aid of a chrome mordant:-(1) The dyestuffs described in Specification 13604/14 prepared by condensing benzaldehyde or o-chlorbenzaldehyde with oxyethyl-o-toluidine or oxyethyl-ethylaniline are treated with concentrated sulphuric acid; instead of the finished dyestuffs the leuco compounds may be sulphated. (2) Dioxydiethyldiamino-diphenylmethane is heated with strong sulphuric acid, the sulphato acid converted successively into the calcium and sodium salts, and the latter oxidized together with dimethyl- or diethyl-aniline, or ethyl-o-toluidine. (3) Michler's hydrol is condensed with dioxydiethylaniline, and the leuco compound heated with sulphuric acid and then oxidized with lead peroxide. (4) Diethyldioxyethyl - diamido-diphenylmethane - o - sulphonic acid is heated with sulphuric acid and then with salicvlic acid and the leuco compound oxidized with lead peroxide; the o -sulphonic acid may be replaced by the corresponding carbinol, and the salicylic acid by o-cresotinic acid, benzoic acid, o-toluic acid, 2 : 7-naphthalene-disulphonic acid, or R-salt. Azine dyes.-An acid azine dyestuff dyeing wool reddish blue is obtained by treating with cold sulphuric acid the oxyethylated azine from nitroso-dimethylaniline and sym-dioxyethyl-m-phenylenediamine described in Specification 182,031. Oxazine dyes.-Acid oxazines dyeing wool blue, violet-blue and green-blue shades, in some cases on a chrome mordant, are obtained by treating with concentrated sulphuric acid the following oxazines prepared as described in Specification 182,031:-(1) the gallocyanine from p-nitrosooxyethyl-o-toluidine and gallic acid; (2) the dyestuff from nitroso-dioxyethyl-m-aminophenol and benzyl-a-naphthylamine; (3) the dyestuff obtained by further condensing the basic gallocyanine from nitroso-oxyethyl-ethylaniline and gallanilide, with asym-dioxyethyl-p-phenylenediamine. Thiazine dyes.-An acid thiazine dyestuff dyeing wool reddish blue is obtained by treating with sulphuric acid the basic thiazine (preferably zinc free) prepared from oxyethyl-o-toluidine as desscribed in Specification 182,031. Oxyalkylated amines are obtained by the method described in Specification 13956/04 by condensing the parent amines with halogen hydrins, for example ethylene, propylene, butylene, or glycerol chlorhydrins. Unsym-disulphato-diethyl-p-phenylene diamine is obtained by treating disulphato diethylaniline with nitrous acid and reducing the nitroso body with zinc dust and acid. Dioxydiethyl - diamino-diphenylmethane-o -sulphonic acid.-Oxyethyl-ethyl aniline is heated with formaldehyde and the methane base dissolved in formic acid and oxidized with lead peroxide. The resulting hydrol, freed from lead is then dissolved in formic acid and heated with sodium bisulphite; the sodium salt of the o -sulphonic acid, from which the free acid may be obtained, is then salted out. Chlorethylhydrogen sulphate is obtained by dissolving ethylene chlorhydrin in concentrated sulphuric acid.