302 IRON. 



Salts oj Iron, 



Sulphate of Iron. Ferri sulphas. — This salt is prepared by 

 dissolving iron in dilute sulphuric acid, and evaporating the solu- 

 tion ; the water is decomposed, its oxygen, the iron, and the acid 

 unite, and hydrogen gas is disengaged. It is prepared, for the 

 various purposes to which it is applied in the arts on a large 

 scale, from the sulphuretted ores of iron, by exposing them to air 

 and moisture, till a crust of sulphate of iron is formed on their 

 surface, which is afterwards obtained in crystals, by solution and 

 evaporation. Sulphate of iron is known in commerce by the name 

 of qreen vitriol, salt of steel or copperas, and is obtained in 

 rhomboidal prisms of a green colour, a strong styptic taste, and 

 soluble in about their weight of water at 60°. It is one of the most 

 active preparations of the metal, and is frequently prescribed with 

 advantage, combined with the cinchona bark, in scrofulous affections, 

 and in amenorrhoea, with bitter extracts, or with myrrh. It is 

 given in the form of pills, conjoined with aromatics, to prevent its 

 griping. Its medium dose is from one to three grains. Exter- 

 nally, it has been used as a lotion to cancerous sores and ill-con- 

 ditioned ulcers. 



Tartarized Iron. Ferrum tartarizalum. — It is obtained by 

 triturating iron filings and super -tart rate of potass with water, 

 exposing the mixture to the action of the air and moisture for 

 twenty days, then boiling it in distilled water, and evaporating the 

 filtered solution to dryness. The tartarized iron forms a powder 

 of a brownish -green colour ; it is very soluble in water, and 

 attracts moisture from the atmosphere, so as to become moist, but 

 does not deliquesce. It has been employed as a chalybeate in a dose 

 of from grs. x. to sss., given either in the state of solution or in 

 the form of pills. It is a very mild preparation, and, as it is 

 nearly tasteless, proves a convenient form for the administration of 

 iron to children. It has been erroneously supposed to possess a 

 diuretic power ; hence it has been extolled as a remedy in dropsy. 

 Ammoniated Iron. Ferrum ammoniatum, Ph. L. — To prepare 

 this saline compound, equal parts of themuriate of ammonia and red 

 oxide of iron are put into a crucible, and subjected to sublimation. 



