part in. Metallic Preparations. — Iron.

655

riatic acid, forming- a muriate of lime, while the disengagedammonia unites with the oxide of copper of the verdegris, andforms a soluble compound. It differs from the simple solutionof ammoniated copper, in holding also the muriate of lime insolution; and is a stronger preparation, for nearly one-halfof the oxide of the ammoniated copper is precipitated by theexcess of water.

Medical properties and tises. — This solution is detergent,and mildly escharotic. It forms an useful local stimulant forcleaning foul indolent ulcers, and disposing them to heal; andis also employed, still more largely diluted, for removingspecks from the cornea.

SOLUTIO SULPHATIS CUPRI COMPOSITA, Edin.Compound Solution of Sulphate of Copper.

" Take of sulphate of copper, sulphate of alumina, eachthree ounces / water, two pounds; sulphuric acid, one ounceand a half. Boil the sulphates in the water, to dissolve them;and then to the liquor filtered through paper add the acid."

This preparation is a simple solution of the sulphates. It issometimes used as a styptic for stopping haemorrhages; andlargely diluted as a lotion in ophthalmia tarsi, and the purulentophthalmia of infants.

As lias been ah'eady noticed (Part ii.), sugar is the best an-tidote for the salts of copper, when these have been taken aspoisons.

PRj&PARATA E FERRO.

Preparations of Iron.

LIMATURA FERRI PURIFICATA, Edin. PurifiedFilings of Iron.

" Having placed a sieve over the filings, apply a magnet,so that it may draw the filings upwards through the sieve."

Sy/i. Limaille de Mars (F.)> GepBlyertes Eisen (G), Limatura di Ferro (/.),Eeramboo Podia (Tarn.).

The iron filings obtained from the workshops are alwaysmixed with many impurities, and often with filings of copperand other metals. It requires some address to purify them bythis process; at least the sieve must not be placed too closeupon the filings, but as distant as the sphere of attraction ofthe magnet will admit of, so that the iron only may be raised.

OX1DUM FERRI NIGRUM PURIFICATUM, Edin.Purified Black Oxide of Iron.

" Let the scales of the black oxide of iron, found at theanvil of the blacksmith, be purified by the application of the