j'akt in. Metallic Preparations. — Iron.

515

" Let the scales of the black oxide of iron, found at theanvil of the blacksmith, be purified by the application of themagnet; for the magnet attracts the thinner and purer scalesonly, leaving the larger and less pure."

Oxydvm Ferri nigrum. Dub. Black Oxide of Iron.

" Let the scales of iron, found at the blacksmith's anvil, bepurified by the application of the magnet. Then reduce themto a powder, the finest parts of which are to be separated inthe manner ordered for the preparation of chalk."

The scales struck off from red-hot iron by the hammer ofthe blacksmith are imperfectly oxidized, but still retain theirmagnetic quality in a sufficient degree to admit of being pu-rified in the above manner.

Medical properties and uses. —This imperfect oxide is tonic,deobstruent, and anthelmintic. It is efficaciously administeredin general debility, dyspepsia, chlorosis, and worm cases. Itsutility is determined by its meeting with acid in the stomach,which is known to be the case by the disagreeable eructationsit produces, and the black colour of the alvine evacuations.The dose is from grs. v to 3j, combined with any aromaticpowder, or formed into an electuary with honey, and takentwice a day.

FER'RUM AMMONIATUM. Lond. AmmoniatedIron.'

" Take of subcarbonate of iron, muriate of ammonia, eacha pound. Mix them accurately together, and instantly sub-lime, by the application of a strong heat; finally, reduce themto powder."

Murias Ammonije et Ferri. Edin. Muriate of Ammoniaand Iron,

" Take of the red oxide of iron washed and again dried,muriate of ammonia, each equal parts by weight. Mix themwell together, and sublime by a quick fire. Reduce the sub-limation to powder and preserve it in a well stopped phial."

Murias Ammonite et Ferri. Dub. Muriate of Ammoniaand Iron.

" Take of red oxide of iron, muriate of ammonia, eachequal parts by weight. Having mixed them well together,sublime them with a sudden and sufficiently strong heat."

Of these processes, those of the Edinburgh and Dublin Col-leges are to be preferred, for the reasons below stated. Thetheory of the operation is obvious: the sudden application ofan intense heat enables the oxide of iron to decompose the mu-riate of ammonia, and to unite with part of its muriatic acid,

• Ferrum ammoniacale, P. L. 1787.haliges Salzsaures Ammonium (G.)

Fleurs de Mars ammoniacale* (F.) Eisen-

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