Sal martis. Salt of steel. Chalybis sal, now called ferrum vitriolatum. Vitriolated iron.-take filings of iron, vitriolic acid, by weight, of each eight ounces; distilled water, three pints; mix them in a glass vessel, and when the effervescence has ceased, place the mixture for some time on hot sand; then pour off the liquor; filter it through paper, and after proper evaporation let it crystallize. Pharm. Lond. 1788. It is given from three or four grains to twenty; is supposed to quicken the circulation, give tone and vigour to the system, and destroy worms: ten grains may be dissolved in a pint of water, and given in repeated draughts, with proper exercise, as a chalybeate water.

Extractum martis.- Iron filings are to be dissolved in some vegetable acid, and then evaporated to a due consistence.

For the crocus martis aperiens, and crocus martis as-tringens, the college of London substitutes the colcothar vitrioli. They are all the red calx of iron, and the least active of the chalybeates. M. Beaume observes, that these calces recover their metalline state by digesting in olive oil during an hour or two.

As usual, we shall add a short account of those preparations of iron which have been commended by former authors, and particularly the practitioners on the continent, at present disused in this kingdom. The croci martis merit a little further notice in this part of the article. They have been differently prepared, and had many different appellations, according to the fancy or object of the chemist. Sometimes the iron has been calcined by fire, sometimes by acids, and occasionally by moistening it only, when it does not differ from the rubigo ferri. Iron calcined by 6re gives the crocus martis obstructivus; deflagrated with common salt and nitre, or nitre and sulphur, it is the pulvis cachecticus of Boecler. If a piece of sulphur is rubbed on a hot iron, and the drops suffered to fall into cold water, it affords the crocus martis aperitivus (crocus martis niger, and chalybs cum sulphur preparatus). The crocus martis sulphuratus (chalybs and Mars sulphuratus) is made by stratifying filings of steel with sulphur in different proportions, moistening the mixture till it grows hot and swells. It is then powdered and subjected to a violent heat with continual stirring, till it becomes a black powder. When still further heated, to separate the whole of the acid, and further to calcine the iron, it becomes red, and is then the crocus martis aperiens. When further heated, it is converted to a mere calx, and is the crocus martis astringens (adstrictorius of Sa/a ). It will be obvious that the calces, in all these tedious preparations, are only in the progressive state, from the black to the red oxide, formerly described, and differing little from the common calces of iron.

In various foreign pharmaceutical works, the rust of iron is differently prepared, without seemingly altering its properties. The filings of steel are sometimes moistened with dew, with vinegar, with urine, particularly of boys, solutions of common salt, (crocus martis emena-gogus;) of borax, or tartarized tartar: sometimes the different mineral acids are employed either in the forms of fluid or vapour, and the rust then acquires other properties. From these it is precipitated by alkalis, particularly caustic ones, or the acid is expelled by heat. By repeating these processes, Schroeder obtained a crocus chalybis ruber, which he highly commends. A crocus martis is also obtained by agitating the iron in carbonic acid water, vinegar, or a highly diluted nitric acid, washing the paste which results, and drying the light powder which subsides.

The Mars so/ubilis alcalisatus of the old, and particularly Lewis's Dispensatory, differs little from the tar-tarised steel already described. The globuli martiales differ only in containing a smaller proportion of the acid, and are employed externally in contusions, luxations, and gun-shot wounds.

The acetas ferri is directed only by the Dublin college as the basis of a tincture. The substance is ordered by the Wirtemburgh college; and the tincture is sometimes denominated from Radcliffe. It is usually prepared from the filingsof steel, or the martial ethiops, united with the vegetable acid; and is highly commended by Boerhaaveas a tonic and anthelmintic, particularly as an antirachitic. When inspissated, it is styled ex-tractum martis.

Tinctura martis cydoniata is particularly described by Wedelius, and usually exhibited with spirituous cinnamon water. We find it commended in the same diseases as are supposed to be relieved by the other chaly-beates, and particularly in puerperal discharges. The tinctura martis pomata, a solution of iron in cyder, and the tinctura martis cum vino malvatico andpomis auran-tiorum, are similar medicines of no peculiar qualities. The two first are sometimes inspissated into an extract. The last is a very weak, inert preparation.

Tinctura nervina of Bestuchef; tinctura nervino to-nicafavaj guttae auree Lamottii, liquor nervinus al-bus, liquor anodynus martialus, are the appellations of a secret medicine, purchased by the empress of Russia, and published. This tincture is generally of a beautiful golden colour if exposed to the sun's light, which is lost in the shade, and returns again in sunshine: it deposits a blue sediment by the addition of the Prussian alkali; and is, like the other tinctures of steel, a tonic. It is a vitriolic ether, with a portion of spirit of wine, holding in solution muriated iron.

The last preparation which we shall mention is the serum lactis chalybeatum, prepared by quenching hot iron in whey. It is commended as a tonic'; but we can find no very distinct account of the diseases to which it is peculiarly adopted.

See Lewis's Materia Medica: Neumann's Chemical Works.

Ferrum ammoniacale. See Ferrum.

Ferrum equinum. Horse shoe vetch. Hippo-crapis uni siliquosa Lin. Sp. Pi. 1049. Dale adds that all the species are astringent.

Ferrum tartarizatum. See Ferrum.

Ferrum vitriolatum. See Ferrum.