4160. Citrate of Iron

4160.    Citrate of Iron. This salt is easily formed by digesting iron filings or wire with citric acid, and evaporating the solution as quickly as possible out of contact with the air. It presents tho appearance of a white powder, nearly insoluble in water, and rapidly passing to a higher state of oxidation by exposure to tho air. Its taste is highly metallic, It is usually administered in tho form of pills, mixed with gum or syrup, to prevent premature decomposition.

4161. Iodide of Iron

4161.    Iodide of Iron. Mix together 6 ounces iodine, 2 ounces iron filings, and 41/2 pints water; boil in a sand-bath until tho liquid turns to a pale green, filter, wash the residue with a little water, and evaporate the mixed liquors in an iron vessel, at 212°, to dryness, and immediately put tho iodide into well-stoppered bottles. A great deal has been written and said about the preparation of iodide of iron, but there is in reality very little difficulty in tho process. As soon as iodine and iron arc mixed together under water, much heat is evolved, and if too much water bo not used, tho combination is soon completed, and the liquor merely requires to bo evaporated to dryness, out of contact with tho air, at a heat not exceeding 212°. This is most cheaply and easily performed by employing a glass flask, with a thin broad bottom and narrow mouth, by which means the evolved steam will exclude air from the vessel. Tho whole of the uncombined water may be known to be evaporated when vapor ceases to condense on a piece of cold glass held over the mouth of tho flask; a piece of moistened starch paper occasionally applied in the same way will indicate whether free iodine be evolved; should such be tho case, the heat should bo immediately lessened. When the evaporation is completed, tho mouth of tho flask should bo stopped up by laying a piece of sheet India-rubber on it, and over that a flat weight; tho flask must be then removed, and, when cold, broken to pieces, the iodide weighed, and put into dry and warm stoppered wide-mouthed glass phials, which must be immediately closed, tied over with bladder, and the stoppers dipped into melted wax.

4162. Ammonio - Citrate of Iron

4162.     Ammonio - Citrate of Iron. Take 121/2 ounces carbonate of soda, and 12 ounces sulphate of iron; dissolve each separately in 6 pints boiling distilled water. Mix tho solutions while hot, and allow the precipitate to subside. Decant the liquor, and, after washing tho precipitate frequently with water, drain it. Then add to it 6 ounces citric acid in powder, and dissolve the mixture by a gentle heat. When cool, add 9 fluid ounces liquor of ammonia of specific gravity .960. It must then be filtered, gently evaporated to tho consistence of syrup, and spread very thinly on warm sheets of glass to dry, which it will rapidly do, if exposed in an atmosphere of warm dry air, and may then be easily detached from tho glass, in thin scales of great brilliancy and beauty. Only a gentle heat must be employed, not exceeding that of a water-bath. This is the method of producing those beautiful transparent ruby-colored scales which are so much admired. It must be kept in well-stopped bottles.