FERROUS SULPHATE 193 



Derivation — Hydrogen gas is passed over freshly made 

 and caref nllv washed ferric oxide in a hot and closed tube. 

 Fe,03 + 3 H, = Fe, + 3 H,0. 



Properties.— A very fine grayish-black, lustreless powder, 

 without odor or taste ; permanent in dry air ; insoluble in 

 water or alcohol. 



Dose.—H.., 3 i.-ii (4.-8.); C, 3 ii.-iv. (8.-15.); Sh. &. Sw., 

 gr.xx.-xxx. (1.3-2.); D., gr.i.-v. (.06-.3). 



Febri Sulphas. Ferrous Sulphate. Fe So^ + 7 H^O. 

 (U. S. & B. P.) 



Synonym. — Copperas, green vitriol, vitriolum martis 

 purum, sulfas ferrosus, ferrum vitriolatum purum, E.; ferrum 

 sulphuricum purum, P. G.; sulfate de fer, sulfate ferreux, 

 Fr.; schwefelsaures eisenoxydul, G. 



Derivation. — Iron wire is dissolved by boiling in diluted 

 sulphuric acid. Fe, + 2 H,SO, = 2 Fe SO, -1- 2 H,. 



Properties. — Large, pale, blueish-green, monoclinic 

 prisms, without odor, and having a saline, styptic taste; 

 efflorescent in dry air. On exposure to moist air the crystals 

 rapidly absorb oxygen and become coated with brownish- 

 yellow, basic ferric sulphate ; soluble in 1.8 parts of water ; 

 insoluble in alcohol. 



Dose.—S.., 3 i.-ii. (4.-8.); C, 3 ii.-iv. (8.-15.); Sh. & Sw., 

 gr.xx.-xxx. (i.3-2.); D., gr.i.-v. (.06-.3). 



Febbi Sulphas Exsiccatus. Exsiccated or Dried Ferrous 

 Sulphate. 2 FeSO, + 3 H,0. (U. S. & B. P.) 



Synonym. — Ferrum sulfuricum siccum, P. G; sulfate de 

 fer desseche, Fr.; entwasserte schwefelsaures eisenoxydul, G. 



Derivation. — Allow ferrous sulphate, 100, to effloresce at 

 a temperature of 104° F. Then heat on a water bath till 

 the product weighs 65. 



Properties. — A grayish-white powder, soluble in water. 



Dose. — Same as sulphate. 



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