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Show 766 COMMON COMMON OAK. OAR. The lichter sort of hides, called dressing hides, as well as horse hides, are managed nearly in the same manner as skins, and are used for coach-work, harness-work, &c. It has been said that every part of the oak tree’ contains a 1g great portion of astringent gu nmy-resinous Aue; = mill therefore tan leather as effectually as the bark itself. This opinion, which was first published in 1674 by the honourable l'rans. vol. ix.), has since been counteCharles Howard (1 nanced by the celebra ied Buffon; who adds, that the bark of birch will answer the purpose of tanning even sole leather, which, it is well known, requires the strongest and most pene| trating materials. the recommends Gleditsch, M. by A long memoir, written plants numberof vast a of flowers, and fruit, branches, leaves, as substitutes for oak bark. Heath dried and pulverized, gall nuts, and the bark of birch, are said by M. Gesner to be used in different provinces of Germany. Abbe Nollet ee us, that the leaves of myrrh are used by the tanners in Naples: In Corsica they make use of the leaves of wild laurel dried in the sun an 1 beaten into powder, and in the island of St. Kilda they tan with the tormentil root. In someparts * Italy leather tanned with myrtle leaves. In Russia it is said that leather Is tanned with the bark of willow; andit mayhere be observed, that a late writer has recommended’ the extract of bark to be made in America, in order to lessen the expense offreight, &. in conveying the bark itself to Europe. in concelconsists in chie plan consists > ‘This chiefly i This plan in half the usual time.’? ; schanical 1bark into { a strong ss extract, ee oe. some mechat and in son eae trating the : E © a € u tan-yard. improvements in the construction of the “ft L } seen ad ., the one nor the other has yet been adopte d. application as. byby the ap] seLondon has, 7 rer in An ingenious manufactu properly stove 45 f of \warm air, conveyed by means of flues from stoves pro} ° senerally kknow ly generally not contrivances sonstructed, and by other Some €X« tanning. t 1 the i usual process«< of of tanning. abridged considerably periments have likewise been made with the bark of ash and of horse chesnut. A substitute for oak bark, the price of which has lately been enormous, is the grand desideratum in. the manufacture of lea. ther. Most of these above enumerated have hitherto been found ineffectual ; but a patent, bearing date 16th J: nuary 1794, has been granted to Mr. Ashton, of Sheffield, Yorkshire, for his discovery of a cheap and expeditious method of tanning leather. This method chiefly consists in applying a preparation of mineral substances instead of oak bark. Those which, on account of their cheapness, are most to be preferred, are the dross of coalpits, called sulphur stone orpyrites, and the yellow ferruginou s earth or red ochre; and, in general, all astringent, sulphureous, or vitriolated- substances, If this discovery, which is yet in its infancy, should prove successful, it may cause a material alteration in the process of this manufacture; and, by reducing the expense, may ultimately be of great advantage to the public. Many other experiments are now making in England for the improvement of tanning ; and as there are many persons of ingenuity and knowledge engaged in the leather man ifacture, much maybe expected from their industry and skill. The revenue arising from the duty on leather tanned in Great Britain (exclusive ofoiled leather) is upwards of 200,000. per annum, MEDICAL VIRTUE. age In the year 1765 the Society of Arts, &c. granted ' ed of 10CJ. for the discovery of a method of tanning with vak es dust; which method has been adopted in Germany: ane ubstitute (menRev. Mr. Swaine ha |lately revived the explod ; vale tioned by Gleditsch and others) of oak leaves. ste Sec Vrsa patent, hae } 17 h : dated obtained Day, esq. of London, Anthony bark the half with <¢ 1790, for a new methodoftanning, ; , 1 J uly 767 The astringent effects of the oak were sufficiently known to the ancients, by whomdifferent parts of the tree were used; but itis the bark which is now directed for medicinal use by our pharmacopeias, To tl uis tree we mayalso refer the galle, or galls, which are produced from its leaves by means of acertain insect, Oak bark manifests to the t aste a strong astringency, accom. pan ied with a moderate bitt both by water and byrectif erness, qualities which are extracted iedspirit. Its universal use and pref ers €nce in the tanning ofle ather is a proof of its great astringency, and like other astrin gents it has been recommendedin agues, and for restraining h emorrhagies, alvine fluxes, and other im. moderate evac uations. A decoction of it has likewise been ad- Yantageousl y employed as a gargle, and as a fomentation or ‘olin in procidentia recti et uteri. Dr. Cullentells us, that he |