Of the syrups Plenck's mercurial syrup is well known. Bellet asserts that his syrup contains no mineral acid. Girtanner, however, and Swediaur, have ascertained that the mercury has been dissolved in the nitrous acid precipitated by the vegetable alkali, then dissolved in vitriolic aether, and sweetened. The precipitate of which it is formed was found to retain no inconsiderable proportion of the acid. Girtanner also informs us, that Velno's syrup does not differ from Belief's. The rob antisyphiliticum of Laffecteur is nearly similar; but some authors contend that a small portion of corrosive sublimate is added.

The various troches, particularly the anthelmintic rotulae and tabellae of Morelli, Zwelfer, and Le Mort as well as the rotulae infantiles laxativae of Schroeder, owe their virtue to calomel and some active cathartic. In these we may find the source of the various worm-cakes and lozenges, celebrated by names of high respectability in this country, who do not, however, rank among medical authorities. The secret remedy of Nicole is formed into little cakes, and supposed to contain corrosive sublimate, though denied by the author. The trochisci tonici mercuriales of Bru, are formed by an operose process which we need not particularly describe, as the medicine is no longer employed: they consist of a mixture of turpeth mineral with white precipitate, and are made into lozenges with honey, sugar, and meal. Each lozenge contains about two grains of mercury.

The drops contain mercury so much concentrated as to be given in very small doses. Of Ward's drops we now know the form. They consist of mercury precipitated from its solution in aqua fortis by the volatile alkali, and again dissolved in rose water. The anti-venereal tincture,or quintessence ofmollet, contains mercury united with the muriated ammonia, a subject on which we shall soon again speak. The liquor mercurii secretus of Gmelin is given in drops, but it contains little or no mercury. Four ounces of the muriated mercury are dissolved in twelve ounces of vinegar: the fluid is drawn off, and the residuum infused, repeatedly, in spirit of wine, which is drawn off by distillation after being for many days digested in a gentle heat. Libavius' tincture of quick silver contains as little of the mercury. Nitrated quicksilver is digested with the brown oil of vitriol, which is repeatedly drawn off till the residuum becomes red. From this, spirit of wine is also repeatedly distilled and somewhat inspissated.

The Thibet remedy, described by Mr. Saunders in the 79th volume of the Philosophical Transactions, merits also some notice. It consists of a portion of alum, nitre, vermilion, and quicksilver sublimed, and appears to be a nitrated mercury of a mild operation.

The drops of General La Motte are of a beautiful red colour, and supposed to be preparations of red precipitate or cinnabar in an acrid fluid, of which a few drops are taken in tea. The elixir antisyphiliticum of Bouez de Sigogne is, in the opinion of Astruc, similar; and the dose, as well as the mode of exhibition, the same.

We shall next follow the less common preparations of mercury in a chemical order. In speaking of the sulphurated preparations of mercury we need not enlarge on the AEthiops mineral, though its formula has been infinitely varied, and numerous discussions on its virtues and preparations lie before us. The AEthiops mineral forms the basis of the pilulae AEthiopicte of the Wirtemburg Dispensatory, in which this preparation supplies the place of calomel, in a formula not unlike Plummer's. The AEthiops narcoticusof Jacobi, described in the Acta Naturae Curiosorum, is more curious. Two ounces of quicksilver are dissolved in four ounces of smoking nitrous acid, and boiled with two pounds of a caustic lixivium, two ounces of potash, and four ounces of sulphur. The sediment is well washed, and is the pulvis narcoticus. This powder, triturated for three days with the AEthiops mineral, becomes, it is said, an active antisyphilitic, without producing salivation. Navier's mercurial, said to be particularly useful in scrofulous and cutaneous complaints, is prepared by precipitating mercury dissolved in hepar sulphuris by any chalybeate neutral. The panacea mercurialis nigra, the panacea of Schroeder, consists of mercury, sulphur, and sal ammoniac, united by sublimation. It differs little from cinnabar except in its darker colour. The panacea Anwaldina is chiefly cinnabar, with some saffron and oyster shells. The cinnabaris caerulea of Wallerius, mercuriu8violaceu8 Parisiensium of Triller, and the mer-curius violaceus diaphoreticus of Astruc, differ only in colour from cinnabar; a change occasioned by a combination of sal ammoniac. The mercurius diaphoreticus of Sir Kenelm Digby is prepared by subliming a pound of mercury with four ounces of sulphur auratum anti-monii.

The union of mercury with other metals has been often attempted, and the compound supposed to be highly useful. With lead it has been employed in the iliac passion; with tin against worms; and with iron in chronic disorders. Corrosive sublimate dissolved in water, mixed with a solution of iron in vinegar, we are told by Navier, is void of acrimony, and useful in many chronic diseases. The mercurius dulcis martiatus of Hartmann, is a similar union of a martial calx with mercury.

The mercurius diaphoreticus consists of the calces of mercury and antimony with a calx of gold; for gold has been always considered as a cordial and a diaphoretic. It is celebrated even by Hoffman, under the name of the solar precipitate, Hercules bovii, and auri vitae Clossaei. The panacea de la vigne contains mercury with gold and silver; the praecipitatus Solaris, with gold only; and many similar ridiculous preparations are described by Zwelfer, Hercules Saxonia, Schroeder, Hartmann, Jungken, and Lemery, under the titles mercurius dulcis Solaris, manna mercurii, and arcanum co-rallinum. The mercurius praecipitatus viridis, or lacerta viridis, contains copper united with mercury.