Rectified spirit of wine receives from bark a deep reddish brown colour, and takes up much more of its active matter than watery liquors* (a): by digesting the powder first in some rectified spirit, and then boiling it in water, nearly the whole of its virtue is pretty readily got out. On infpiflfating the filtered tincture, the spirit carries off nothing remarkable of its smell or taste: the remaining extract retains the peculiar flavour of the bark, as well as its aitringency and bitterness, and proves a very elegant preparation, preferable to the pure resin obtained by precipitation from the tincture by water, as containing a part of the gummy matter, which is a medicinal principle of the bark as well as the resin. The spirituous tincture, and the decoction of the residuum, may be united into an extract, poffefling this advantage in a greater degree, by infpiffating them separately to the consistence of a syrup, then mixing them together, and continuing the evaporation with a gentle heat.

Proof spirit extracts less from bark than rectified spirit, but more than water. Four ounces of the powder, macerated for some days without heat, in a quart † or two pounds and a half ‡ of proof spirit, impart a considerable degree both of bitterness and astringency: on applying heat† , the taste becomes stronger, the colour darker, and the liquor somewhat turbid; from whence it may be concluded, that the resinous part is not by this menstruum completely dissolved.

* (a) See Dr. Percival's different opinion, at the note in page 201.

Extr. cort. peruv. Ph. Ed. Extr. cort. peruv. cum refina, Ph. Lond.

Spirit of sal ammoniac made with fixt alkaline salt, by maceration with powdered bark in the above proportion, receives from it very little taste or colour. The spirit prepared with quicklime, and the dulcified spirit, extract in a few hous a very deep colour, and become strongly-impregnated with its virtue. Though the spirit made with quicklime is held too acrimonious to be given internally by itsel, it is not liable to that objection here; its pungency being ftieathed by the substance which it dissolves.

Among the several substances which I have tried for covering the taste of bark, to some persons offensive, liquorice seemed to answer the best. Aromatics alone leave the taste of the bark very sensible in the mouth; but liquorice appeared to cover it effectually, whether in draughts or electuaries, with the bark in fubflance or its preparations: to this compound any proper aromatic material may be superadded, to give a grateful favour. For liquid forms, an infusion of the liquorice, and for electuaries the extract should be used: for making up the electuaries, mucilages are more proper than syrups, as the former occasion the compound to pass down freely without sticking about the mouth and fauces.

* Peruvianus cortex ruber: Red Peruvian bark. In the year 1779, a Spanish ship from Lima was taken by an English frigate, and carried into Lisbon. Her cargo chiefly consisted of bark, part of which was afterwards brought to London, and purchased by several druggists. From its large coarse appearance, it was sometime before practitioners could be prevailed on to use it. At length, it was tried in some of the hospitals, and found to be so efficacious, that an opinion soon prevailed of its being of a much superiour quality to the best common bark. Trials were multiplied throughout the kingdom, in a year when intermittents were remarkably frequent and obstinate; and its reputation increased with every experiment. Chemical tests were equally favourable to it, as they proved it to contain a much greater proportion of active matter, than the other sorts. At length, Dr. Saunders, a physician in London, eminent for chemical knowledge, published a treatise, in which various experiments on this bark were related, and attestations of its great medical efficacy from several practitioners were annexed. From this pamphlet, together with the editor's own experiments, the following account is extracted.

† Tinct. cort. peruv. Pb. Lond.

‡Pb. Ed,

The red bark, as it is called, is in much larger and thicker pieces than the common. Most of the pieces are concave, though not rolled together, like the quilled bark. They break short, like the best common bark; and appear evidently composed of three layers. The outer is thin, rugged, frequently covered with a mofTy substance, and of a reddish brown colour. The middle is thicker, more compact, and of a darker colour: it is very brittle and resinous. The innermost layer is more woody and fibrous, and of a brighter red. In powdering this bark, the middle layer, which seems to contain the greatest proportion of resinous matter, does not break so readily as the rest; a circumstance to be attended to, lest the most active part should be left out of the fine powder.

This red bark to the taste discovers all the peculiar flavour of the Peruvian bark, but much stronger than the common officinal sort. An infusion in cold water is intensely bitter; more so than the strongest decoction of common bark. Its aftringency is in an equal degree greater than that of the infufion of common bark, as is shewn by the addition of martial vitriol. The spirituous tincture of the red bark is also proportionally stronger than that of the pale. The quantity of matter extracted by rectified spirit from the powder of the former, was to that from the latter, as 3 to 2 in one experiment, and as 229 to 130 in another. And yet, on infufing the two residuums of the first experiment in boiling water, that of the red bark gave a liquor considerably bitter, and which struck a black with martial vitriol; while that yielded by the other was nearly taste-less, and void of astringency.

With respect to medical properties, from numerous and repeated trials it appears, that the red bark poifeffes the same virtues with the common, but in a much higher degree. A single half ounce of this has radically cured an obstinate intermittent, where many ounces of the other kind had either had no effect, or merely a temporary one.