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ELEMENTE OF MATERIA MEUICA.

OTHEK FERBÜGINOÜS COMPOUNDS.

!■• FERRI PERSULPHAS; Persulphate of'Iron. —The mode of Converting sulphate of the pro-toxide into sulphate of the sesquioxide of iron has been already pointed out (see p. 690.) Per-sulphate of iron combines with albumen to form a pale yellowish compouiid ; {Journ.de Chim.Med. t. vi. 2 de Serie, p. 308.) on this property depends its chemical action on the tissues. Dr.Osborne {Lond. Med. Gaz. March 6, 1840. p. 892.) says, Widow Welch's pills are composedof " sulphate of peroxide of iron, with a small quantity of insipid vegetable matter, probablygum, as much as is requisite for adhesion." It is more probable, however, that they are pre-pared with the common sulphate of the shops, which is a mixture of protosulphate and per-sulphate of iron.

2. FERRI PERN1TRAS; Pernitrale of Iron. —A Solution of this salt has been employed asan astringent in diarrhcea. 1 It is prepared by dissolving iron in diiuted nitric acid to Satura-tion.

3. AMMONI/E FERRO-TARTRAS; Ferro-Tartrate of Ammoma ; Tartrate of Iron and Ammo.nia; Aikin's Ammonia. Tartrate of Iron. This salt was first employed in medicine by Mr.AiUin. (Lond. Med. Gaz. voi. viii, p. 438.)

It may be prepared by adding caustic ammonia to a Solution of tartrate of iron (prepared bydigesting together, for two or three days, one part of tartarie acid, dissolved in hot water,with two or three parts of iron filings.) The green Solution thus obtained is to be evaporatedto dryness by a gentle heat. (Aikin, op. eil.)

[The foüowing fortnula for preparing this salt is commtmicated by Mr. Procter, Am. Journ.of Phormacy, vol. xii. p.276. Take of Tartarie Acid, g x i j. and giv; Carbonate of Ammonia,giv., gvij. and £)j; Sesquioxide of Iron, §vj., gv. and J)j; Hydrochloric Acid, fgxxij.f giv ; Solution of Ammonia and water of each a sufficient quantity. Dissolve the tartarie acidin a gallon of the water and add the carbonate of ammonia gradually. A considerable quan-tity of a white crystallinc powder subsides, which is bilartrate of ammonia and with which thesupernatant liquid is saturated. Dissolve the sesquioxide ofiron in the hydrochloric acid, bymeans of a gentle heat, dilute the Solution with six pints of water and add a sufficient quantityof Solution of ammonia to preeipitate the sesquioxide. Separate this on a flannel filter, washit with water until the washings pass tasteless, and add it to the Solution containing the bitar-trate of ammonia; then apply a gentle heat, by means of a waler bath, until the whole of thesesquioxide ofiron is dissolved and a deep reddish brown Solution results. The Solution thusobtained should he evaporated to dryness by means of a water bath.]

It is in the form of shining brittle Fragments of a deep red colour, not very unlike pieces ofdeep-coloured sbell-lac. It is very soluble in water. Its taste is strongly saceharine.

Its general efi'ects are analogous tb those of the other ferruginous Compounds, except thatit has very Httle if any astringency. Its advanlages over other chalybeates are its readysolubility in water, its palatable taste, and the faciüty with which it may be mixed with va-rious saline substances, without undergoing decomposition. It contains more oxide of ironthan the same quantity of sulphate. The dose for an adult is five or six grains in powder,pill, or Solution. It may be exhibited in porter without being detected by the taste. It maybe added to the Compound decoction of aloes without suffering decomposition.

A Ferro-citrale of Ammonia (callcd Citrate of Iron) is Met with in the shops. Its propertiesare similar to those of the preceding preparation.

4. FERRI LACTAS; Lactate of IroH. —This salt oecurs in beautiful small, green, aeicularcrystals. It has been used in medicine, (British and Foreign Medical Review, vol. x. p.565.) though it does not appear to present any advantages over the other preparations ofiron.

5. VINUM FERRI, Ph. L. 1809; Witte of Iron. (Iron Filings, §ij; Wine, [Sherry] Oij.[wine 7iieasure.] Mix and set the mixture by for a month, occasionally shalung it; then filterit through paper.)—Tbc iron is oxidized by the air and water, and the sesquioxide combineswith the tartarie acid of the wine. It is properly discardcd from the pharmacopoeias.—Dose,3J. to 3'iv.

> See Dr. S. W. Williams, in the Boston ( U. S.) Medical and Surgical Journal, April 7, 1841.