Characters. - A dense solution of a dark-red colour, inodorous and very astringent, miscible in all proportions with alcohol and water.

Reactions. - Diluted with ten volumes of water, it gives the reactions of a sulphate and of a ferric salt only.

Preparations in which Solution of Persulphate of Iron is used.

b.p. Ferri et Ammonii Citras. Ferri et Quininae Citras. Ferri Peroxidum Hydratum. Ferrum Tartaratum.

u.s.p. Ferri et Ammonii Citras.

., ,, ,, Tartras.

„ „ Potassii „

„ Oxidum Hydratum.

,, „ „ cum Magnesi‚.

Liquor Ferri Nitratis.

„ „ Citratis.

Uses. - Not used as a remedy, but to prepare peroxide, etc.