Synonym. - Ferrum Sulphuricum.

Present name. - Ferrous Sulphate. FeSo4,7H1O.

This is the Green Vitriol of commerce, and may be obtained chemically pure from the operative chemists.

Characters and Tests. - In oblique rhombic prisms, of a pale greenish-blue colour and styptic taste; insoluble in rectified spirit, soluble in water. The aqueous solution is clear, gives a white precipitate with Chloride of Barium, a blue one with the red, and a nearly white or light blue one with the yellow Prussiate of Potash. It gives no precipitate with Sulphuretted Hydrogen.

Preparations. - Trituration. Solution in distilled water. Neither of these preparations, however, keep well. The solution may be rendered much more stable by adding a few drops of dilute Sulphuric Acid.