Peruvianus Cortex Pharm. Lond. & Edinb. Peruvian bark: the bark of a mid-dling-fized tree, growing in Peru, called by the Spaniards, from its efficacy against intermitting fevers, polo de calenturas, or the fever tree; by Linnaeus, Cinchona officinalis. This virtue of the bark is said to have been discovered by the Indians about the year 1500, but not revealed to their European masters till 140 years after; when a signal cure having been performed by it on the Spanish viceroy's lady, the countess del Cinchon, it came into general use in those parts, and was distinguished by the appellations pulvis comitissa cortex china china or chinchina, kina kina or kinkina, and quina quina or quinquina. In 1649, a jesuit brought a large quantity of it into Italy, which was distributed by the fathers of that order, at a great price, in different parts of Europe: about the same time a quantity was purchased by cardinal de Lugo for the use of the poor at Rome. From these it received the names of cortex or pulvis jefuiticus, pulvis patrum, and pulvis cardinalis de Lugo.

This bark is brought to us in pieces of different sizes, some rolled up into short thick quills, and others flat: the outside is brownish, and generally covered in part with a whitish moss: the inside is of a yellowish, reddish, or rufly iron colour. The bed sort breaks close and smooth, and proves friable betwixt the teeth: the inferiour kinds appear when broken of a woody texture, and in chewing separate into fibres. The former pulverises more easily than the latter, and looks, when powdered, of a light brownish colour, resembling that of cinnamon, but somewhat paler.

A bark was some time ago brought from America under the name of the female Peruvian bark. This was found, from experience, to be less effectual as a medicine than the genuine sort, which it was frequently substituted to or mixed with in France, insomuch that its importation, as the editor of Geoffroy informs us, was prohibited by law. It is considerably thicker, whiter on the outside, redder within, and weaker in smell and taste than the true bark.

Peruvian bark has a slight smell, approaching as it were to muftinefs, yet so much of the aromatic kind as not to be disagreeable. Its taste is considerably bitter, astringent, very durable in the mouth, and accompanied with some degree of aromatic warmth, but not sufficient to prevent its being ungrateful.

The febrifuge virtue, for which alone this medicine was at first recommended, has now been established by the daily experience of about a century: and that, when judicioufly and sea-sonably administered, it proves as safe as it is effectual, is now also beyond dispute. An emetic, which is in most cases necessary, being taken towards the approach of a paroxysm, that its operation may be over before the fit comes on; the bark is begun at the end of the paroxysm, or even in the time of the hot fit, and repeated, in doses of half a dram or more, every third or fourth hour, during the intermission: after the fever has been removed, the medicine is continued for a time, but more sparingly, to prevent a return. During the use of the bark, the pulse, which betwixt the paroxysms is generally weak and slow, becomes stronger and quicker, the appetite mends, the patient grows more cheerful, and perspiration increases: these may be looked-upon as sure presages of its suc-cess. At first it frequently occasions a looseness, and this also is salutary; but if the purging runs on too long, as the fever rarely yields while this evacuation continues, it is usually checked by the addition of a little opium: if too great cof-tivenefs ensues, recourse is had to glysters. In gross impure habits, gentle purgatives are pre-mised to the bark, or given for a time in conjunction with it: in agues of the inflammatory kind, or accompanied with great heat, a little nitre is joined or interposed: in lax spongy con-stitutions, and a thin watery state of the blood, the bark is alTitted by bitters, snakeroot, camphor, and chalybeates: where obitructions of the abdominal viscera are apprehended, it is not ventured on without the addition of fixt alkaline salts, sal ammoniac, or other aperients. In all cases, moderate exercise, and the drinking of warm liquids, promote its effects. As the bark is hurtful in the inflammatory diathesis, it is not near so effectual in vernal, as in summer and autumnal intermittents (a).

In remitting fevers, this medicine is less suc-cessful than in those which have perfect: inter-misiions: in hectics, or wherever pus is formed, or juices are extravafated, it does harm. In the decline of long nervous fevers or after a remif-fion, and in those of the low malignant kind where the blood is colliquated and the strength exhausted., exhausted, it proves an excellent cordial, corroborant, and antiseptic.

(a) Cull. Mat. Med. 292.

Peruvian bark has likewise been found ser-viceable in gangrenes and mortifications, and in foul obstinate ulcers and running fores of other kinds: in these cases, taken in large and repeated doses, it frequently brings on a laudable suppuration, which degenerates on discon-tinuing the use of the medicine, and again turns kindly upon resuming it. The like effects have been observed from it in variolous cases, where either the pustules did not duly suppurate, or petechiae shewed a disposition to a gangrene: by the use of bark, the empty vesicles filled with matter, watery sanies changed into thick white pus, and the petechiae became gradually paler and at length disappeared. The principal symp-tom in this disease that contraindicates this valuable fuppurant and antiseptic, is great obstruc-tion at the bread or difficulty of breathing; which are always by this medicine increased, insomuch that small doses have in some cases endangered suffocation.

In tumours of the glands, the Peruvian bark appears to promote, not suppuration, but refo-lution. In the Medical Observations and Inquiries published by a society of physicians in London, there are several instances of its being given with success in scrophulous complaints. Dr. Fothergill observes, that inveterate ophthalmias generally yield to it: that beginning glandular tumours are very frequently resolved and their farther progress stopt by it: that swelled lips, cutaneous blotches arising from a like cause, are healed, and the tendency to a stru-mous habit corrected: that it does not succeed in all cases, but that there are few in which a trial can be attended with much detriment: that he has never known it to avail where the bones were affected, or where the scrophulous tumour was so situated as to be attended with much pain, as in the joints or under the membranous covers of the muscles; for when it attacks these parts, the perioisteum, and consequently the bone, seldom escape being injured; that here the bark, instead of lessening, adds to the fever which accompanies these circumstances, and if it does not increase the force of the mischief, seems at lead to hasten its progress.