QUE

459

of the Pharmacopoeia, its credited virtues entitle it to some notice inthe present work. It was first brought into repute in this country by Dr.Somerville (M<-d : Chi rug: Truns: Ful. o). It is bitter, and consists ofResin,gum-resin, tannin, <.nd bitter extractive. [Its virtues are extractedboth by alcohol and water. In its effects upon the system, the pyrola isboth tonic and diuretic. It is more especially, tiovvever, as a diureticthat it is celebrated. Both in Europe and in the United States, it hasbeen administered with much success in dropsy. In nephritis and hematu-ria it has also been used with decided advantage, producing effects verysimilar to those of the Uva Ursi. Dr. Chapman represents it as being ofservice in cases of scrofula ; and by the elder Dr. Barton it was muchthought of as an antilithic. It may be given in tincture in doses of from3j t° 3ij ; or in infusion made by pouring one pint of boiling water up-on ij of the plant, in doses ot from ^j to 3iv.]

QUASSIA, L.E.D. (Quassia Excelsa. Lignum}

Quassia.

This wood owes all its properties to a peculiar bitter principle, whichhas been examined by Dr. Thomson and named Quassia; it is solid,slightly transparent, and of a yellowish brown colour. (See InfusumQuassia ) it is said to owe its name to a West Indian negro, called Qudssi,who tirst used it in fevers.

QUl.RCUS CORTEX. L.E.D.

(Quercus Pedunculata. Cortex.)

Oak Bark.

Qualities. Odour, jone ; taste, rough and astringent. ChemicalComposition. We are indebted to Sir H. Davy ior a knowledge of thissubject; he found that an ounce of the inner cortical part of young oakbark afforded by lixivation 111 grains of solid matter, of which 77 weretannin; and the cellular integument, or middle coloured part, only yield-ed 43 graius of solid matter, of which It' were tannin ; and the epider-mis turnished scarcely any quantity oi tannin or extractive^ hence thebark should be selected from the smaller branches of tne oak where theepidermis is still thin. Experience has, moreover, shewn that the quan-tity of tannin varies considerably, not only according to the age and sizeof the trees, but according to the season at which they are barked,- thus,the bark cut in spring contains, according to Beguin* four times more ofthe astringent principle, than that which is oDtained m winter. Med.Uses All its properties depend upon the presence of tannin, it is there-fore only valuable as a powerful astringent; it is accordingly employed

ways carried about with them. The members of the profession have doubtless heardol an irregular practitioner, who has persuadeda certain number of persons in this me-tropolis, that he possesses remedies, obtained from the American Ind.ans, by which heis enabled to cure Scrofula m its worst tonus ; it is to this Empiric that I alluded inthe note at page 33; and it may be worthy oi notice that the plant upon which he reJies tor success, is the Pyrola Umbellata.Philosophical Transactions, 1799.