Heavy metal compounds of aromatic halogenylsulphamides are dissolved in water with the aid of heterocyclic nitrogenous compounds containing an imido group either attached to or as part of the heterocyclic nucleus, together with an acid or basic group which is attached to the heterocyclic nucleus directly or by means of an aliphatic, alicyclic or aromatic radicle.  When a basic group is present the aliphatic connecting radicle may be interrupted by oxygen, sulphur or nitrogen.  The aqueous solutions obtained are, if necessary, made weakly alkaline; they are useful therapeutically. According to the examples: (1) silver p  p-toluenesulphochloramide is added to a caustic soda solution of benzimidazole - 5 - sulphonic acid, -carboxylic acid or -arsonic acid; (2) benzimidazole-5-sulphonic acid in caustic soda solution is mixed with sodium p-toluene-sulphochloramide or -sulphobromamide and silver nitrate; (3) to a caustic soda solution of benzimidazole-5-sulphonic acid, copper benzimidazole-5-sodium sulphonate (see Specification 388,374) and sodium p-toluene-sulphochloramide are added; (4) an aqueous solution is made up with mercury - 6 - chlorobenzimidazole - 5 - sodium sulphate, 6 - chlorobenzimidazole - 5 - sulphonic acid, sodium p - toluene - sulphochloramide and caustic soda; (5) a solution of benzimidazole-5-sulphonic acid in caustic soda is mixed with sodium p-toluene-sulphochloramide and cobalt chloride; (6) benzimidazole-5-sulphonic acid, benzotriazole-5-carboxylic acid or triazoledicarboxylic acid is dissolved in caustic soda and both chlorauric acid and sodium p-toluenesulphochloramide then added; (7) a solution of benzotriazole-5-hydroxyacetic acid or a -amino-b -imidazolyl-propionic acid in caustic soda is mixed with copper sulphate and p-toluene-sulphochloramide; (8) to a caustic soda solution of diethylbarbituric acid, sodium p-toluene-sulphochloramide and mercury chloride are added; (9) benzene-sulphamide dissolved in caustic soda is treated with sodium hypochlorite, and benzimidazole-5-sulphonic acid and zinc sulphate then added; (10) sodium hypochlorite solution is added to a solution containing benzimidazole - 5 - sulphonic acid, p-toluene-sulphamide, copper sulphate and caustic soda; perimidine sulphonic acid may replace the benzimidazole-5-sulphonic acid; (11) a solution of 5-diethylaminoethoxybenzimadazole in hydrochloric acid is mixed with copper p-toluene-sulphochloramide; (12) silver naphthalene-b -sulphochloramide is dissolved in a solution of benzimidazole-5-sulphonic acid or methylpyrazole-carboxylic acid in caustic soda.  The use of halogen-benzene-sulphohalogenylamides and of 2-(2<1>-carboxylphenyl), benzimidazole is referred to, as well as neutralization of the solutions with organic bases such as dimethylamine, diethylamine, diethylaminoethanol and piperidine. Buffer substances, such as sodium borate, may be added to the solution.  Heavy metal compounds of aromatic halogenylsulphamides are prepared by reacting soluble aromatic halogenylsulphamide salts with compounds of metals having a specific gravity above 5. Thus, copper p-toluene-sulphochloramide is prepared from sodium p-toluene-sulphochloramide and copper sulphate, and silver naphthalene-b -sulphochloramide by interaction of naphthalene - b  - sulphochloramide and silver nitrate.  6 - Chlorobenzimidazole - 5 - sulphonic acid is obtained by condensing chlorophenylenediamine with formic acid and sulphonating.  By reacting the product in alkaline solution with mercury chloride, the mercury compound is obtained. Perimidine sulphonic acid is prepared by treating 1 : 8-diaminonaphthalene-4-sulphonic acid with formic acid.  The formula is given.