Dose. - 5 to 10 gr.

C. Tinctura Ferri Acetatis. - Tincture of Acetate of Iron.

Source. - Made by adding Acetate of Potash and Rectified Spirit to the Solution of the Persulphate, and filtering. Fe23SO4 + 6KC2H3O2 = Fe26C2H3O2 + 3K2SO4.

Characters. - A deep brown liquid,

Dose. - 5 to 30 min.

4. Ferri Sulphas Granulata

Ferri Sulphas Granulata. Granulated Sul-phate of Iron. FeSO4.7H1O.

Source. - Made by pouring a solution of Iron "Wire in Diluted Sulphuric Acid into Rectified Spirit, stirring the mixture; and drying.

Characters. - Small, pale green granular crystals. Solubility, 1 in 1 1/2 of water, insoluble in spirit.

Impurities. - Same as of Ferri Sulphas.

Dose. - 1 to 5 gr.

Preparation.

Syrupus Ferri Phosphatis. - 1 gr. of Ferri Phos-phas in 1 fl.dr.

Source. - Made by precipitating a solution of Granulated Sulphate of Iron with a mixed solution of Phosphate and Acetate of Soda, dissolving the precipitate in Diluted Phosphoric Acid, and adding Sugar.

Characters. - Colourless, becoming brown. 1 fl.dr. contains 1 gr. of Ferri Phosphas (Fe3P2O8).

Dose. - 1 to 4 fl.dr.

5. Ferri Iodidum

Ferri Iodidum. Iodide of Iron. FeI2.

Source. - Made by boiling Iron Wire and Iodine in Water, and evaporating.

Characters. - Crystalline, green with a tinge of brown, inodorous, deliquescent. Consists of iron, 1; iodine, 4 1/2; water, 1 1/4. Solubility, 1 in 1 of water.

Dose. - 1 to 5 gr.

6. Pilula Ferri Iodidi

Pilula Ferri Iodidi. Made by mixing a solution of Iron Wire and Iodine in Water, with Sugar and Liquorice. 1 in 3 1/2. Dose, 3 to 8 gr.

7. Svrumis Ferri Iodidi

Svrumis Ferri Iodidi. Made by mixing a solution of Iron Wire and Iodine in Water with Syrup. Colourless. 4.3 gr. in 1 fl.dr. Dose, 20 to 60 min.

8. Ferri Perchloridi. Liquor Fortior. Strong Solution of Perchloride of Iron.

Source. - Made by adding Hydrochloric Acid and Nitric Acid to a hot solution of Iron Wire in Hydrochloric Acid and Water (1) Fe + 2HC1 = FeCl2 + H1. (2) 6FeCl2 + 6HC1 + 2HNO3, = 3Fe2Cl6 + 4H1O + 2NO.

Characters. - An orange-brown liquid, consisting of per-chloride of iron, Fe2Cl6, in solution in water. Not given internally.

Impurities. - Ferrous salts.

Preparations.

a. Liquor Ferri Perchloridi. - Pale brown. 1 to 3 of water. Dose, 10 to 30 min.

to 3 of spirit. Dose, 10 to 30 min.

9. I.iquor Ferri Pernitratis. - Solution of Per-nitrate of Iron.

Source. - Made by dissolving Iron Wire in Diluted Nitric Acid.

Characters. - A clear reddish-brown liquid, slightly acid and astringent to the taste; consisting of pernitrate of iron, Fe26NO3, in solution in water.

Impurities. - Ferrous salts.

Dose. - 10 to 40 min.

Incompatibilities of Preparations of Iron in General.

Alkalies and their carbonates, lime-water, carbonate of lime, magnesia, and its carbonate, give green precipitates with proto-salts, brown with persalts. Tannic and gallic acids give a deep blue-black with persalts. Preparations of iron therefore tinge infusion of chiretta and hops, and change to brown or black those of chamomile, cusparia, gentian, orange, cas-carilla, cloves, digitalis, cinchona, and all astringent infusions; but they can be given in infusion of quassia or calumba.

Action And Uses. 1. Immediate Local Action And Uses

'Externally. - A solution of iron has a corrugating and astringent effect upon the broken skin and mucous surfaces coagulating the albuminous tissues and plasma, and (unstringing or condensing the elements. The blood-vessels are thus closed or diminished in sue, not actively, but by campret from without; the circulation through them is diminish haemorrhage, if present, is arrested; and the abnormal escape of plasma and leucocytes, which characterises chronic inflammation or catarrh, is checked. Solutions of the ferric salts are therefore used as haemostatics to arrest haemorrhage from accessible parts, such as leech-bites, the nose, and uterus; less extensively in chronic discharges from the vagina, rectum, and nose, as astringents. Injected into the rectum, they destroy worms. Iron is not absorbed by the unbroken skin.

Internally. - The constringent effect of iron is appreciated in the mouth as a "styptic taste." Beyond this, the local action corresponds with that just described externally. Various iron solutions are usefully applied, either as gargles or with the brush, in some forms of chronic sore throat.

In the stomach all the salts of iron, whatever their nature, are converted into the chloride, and do not combine with the acid albuminates, like some of the other metals. Deficiency of hydrochloric acid or of food, or excess of iron, thus decomposes the gastric juice, and allows the iron to act upon the mucous membrane as an astringent and irritant. Iron is thus directly unfavourable to digestion; and in this connection we must carefully note (1) that iron may disorder the digestion even in healthy subjects; (2) that it must not be given for disease until the gastric functions have been so far restored; (3) that it is well to begin then with the mildest preparations; and (4) that it must be given after meals. Iron is a valuable antidote in arsenical poisoning, the humid peroxide (Fe26HO) forming with arsenious acid an almost insoluble compound (As2O3 + 2(Fe2 6HO) = Fe3As2O8 + Fe2HO + 5H1O). Abundance of the iron should be given, and the compound should be quickly expelled by a smart purge of sulphate of magnesia or soda. The solutions of the persalts are used to arrest haemorrhage from the stomach. In the duodenum iron is converted into an alkaline albuminate, and thus absorbed. The further effect of iron on the bowel is a remote one, to be presently described.

2. Action On The Blood, And Its Uses

The action of iron on the blood is almost unique of its kind: first, because its specific action is exerted, not upon the plasma, but upon the red corpuscle, and on this alone, not on any other tissue or organ; secondly, because this action appears to be nothing more than the combination of the iron as one of the constituent elements of the corpuscle with the others. In the case of no other metal can we speak so definitely of its modus operandi.