Contractions. - Ferr-red. F-r.
Metallic Iron with a variable quantity of Magnetic Oxide of Iron. The British Pharmacopoeia directs it to be prepared as follows: -
Hydrated Peroxide of Iron. . . .
Zinc, granulated ....
Sulphuric Acid ....
Chloride of Calcium . . ..
Introduce the Hydrated Peroxide of Iron into a gun-barrel, confining it to the middle part of the tube by plugs of asbestos. Pass the gun-barrel through a furnace, and when it has been raised to a strong red-heat, cause it to be traversed by a stream of Hydrogen Gas developed by the action on the zinc of some of the Sulphuric Acid diluted with eight times its volume of water. The gas before entering the gun-barrel must be rendered quite dry by being made to pass first through the remainder of the Sulphuric Acid, and then through a tube 18 inches long, packed with small fragments of the Chloride of Calcium. The farther end of the gun-barrel is to be connected by a cork with a bent tube dipping under water; and when the Hydrogen is observed to pass through the water at the same rate that it bubbles through the Sulphuric Acid, the furnace is to be allowed to cool down to the temperature of the atmosphere, the current of Hydrogen being still continued. The Reduced Iron is then to be withdrawn, and enclosed in a dry stoppered bottle.
Characters and Tests. - A fine greyish-black powder, strongly attracted by the magnet, and exhibiting metallic streaks when rubbed with firm pressure in a mortar. It dissolves in Hydrochloric Acid with the evolution of Hydrogen, and the solution gives a light blue precipitate with the yellow Prussiate of Potash. 10 grains added to an aqueous solution of 50 grains of Iodine and 50 grains of Iodide of Potassium, and digested in a small flask at a gentle heat, leave not more than 5 grains undissolved, which should be entirely soluble in Hydrochloric Acid.
Preparation. - Trituration.
Proper forms for dispensing. - 1x to 3, Trituration only. 4, dilute Tincture only. 5 and upwards, Tincture, Pilules, or Globules.
A large number of other preparations of Iron have been used and found efficacious, and several of these have been introduced into Jahr's, Gruner's, and Buchner's Pharmacopoeias; Jahr also notices several in his Symp-tomen Codex, and Noack and Trinks refer to them likewise.