Characters. - In oblique rhombic prisms, of a pale greenish blue colour and styptic taste. Solubility. - It is insoluble in rectified spirit, soluble in water. Reactions. - The aqueous solution gives the reaction of a sulphate (p. 594) and of a ferrous salt (p. 736).

Dose. - 1 to 5 grains.

Preparations.

B.P

Ferri Sulphas Exsiccata............

Pilula Aloes et Ferri (vide p. 522) 1 part in 7.

U.S.P. Ferri Sulphas Exsiccata.

Ferri Sulphas Exsiccata, B.P.; Ferri. Sulphas Exsic-catus, U.S.P. Dried Sulphate of Iron. FeSO4.H2O; 169.9.

Prepared by heating sulphate. It is less apt to oxidise, and is well fitted for pills.

Dose. - 1/2 to 3 grains.

Preparation.

u.s.p.

Pilulae Aloes et Ferri (vide p. 523).