one after the other, and allowed to macerate eacii a considerabletime. This, reduced to our standard, gives us about 150 English pints to a pound troy of nutgalls. From the analyses of Deyeuxand Davy, it follows that the soluble part of nutgalls consistschiefly of five ingredients ; namely, tan, extract, mucilage, gaUicacid, and gallate of lime. Mi'. Davy found that 500 grains ofAleppo galls formed with water a solution which yielded, by slowevaporation, 185 grains of matter. This matter he found com-posed of

130 tannin

31 gallic acid and extract12 mucilage and extract12 lime and saline matter

185.

So that the tannin constitutes rather more than two thirds of thewhole. Tannin obtained from the infusion of nutgalls is a brittlesubstance, of a brown colour. It breaks with a vitreous fracture,and does not attract moisture from the air. Its taste is exceed-ingly astringent. It is very soluble in water. The solution is ofa deep-brown colour, a very astringent and bitter taste, and hasthe odour which distinguishes a solution of nut-galls. It froths,when agitated, like a solution of soap ; but does not feel unctuous.Tannin is still more soluble in alcohol than in water. The solu-tion lias a deep-brown colour, and an astringent taste. Whenheated, it blackens, emits carbonic acid gas, and in the open airbursts, leaving always a small portion of lime. The alkalies com-bine readily with tannin, and form with it a compound soluble inwater. This was first observed by Deyeux, whose experimentshave been verified by Mr. Davy. All the earths hitherto triedhave a strong affinity for tannin, and form with,it compounds forthe most part insoluble in water, the properties of which havescarcely been examined by chemists. One of the most importantproperties of tannin is the insoluble compound which it forms withglue or gelatine, as this substance is termed by chemists. It istherefore employed to detect the presence of gelatine in animal-fluids: and, on the other hand, solutions of gelatine are employedto detect the presence of tannin in vegetable fluids, and to ascertainits quantity.

TANNING, the art of manufacturing leather from raw hidesand skins, so as to render it more pliant and durable. The pro-cesses employed for this purpose are various; every tanner adopt-ing some peculiar method; we have therefore selected the follow -ing, which is practised with little difference, in the metropolis andits vicinity ; where the leather is divided into three sorts, knownunder the names of backs, or butts, hides, and skins. Thestrongest hides are selected for the butts; and, after being divestedof the horns, they are laid in heaps for one or two days during thesummer, and for the space of five or six, in the winter. Next,they are suspended on poles in a smoke-house, or room containinga fire made of wet tan, to induce a slight degree of putrefaction, sothat the hair may he stripped off; an object which is effected byspreading such hides on. a wooden horse, and scraping them witha curved knife. They are then immersed in water, lobe cleansedfrom all dirt, and extended a second time on the horse, when all*Mraneous matters must he carefully removed. The hides areflow steeped in a pit containing ooze, or a strong liquor, prepared“y infusing ground oak-bark in water; after which they areplunged into another pit, containing water powerfully impreg-nated with oil of vitriol, or with an acid obtained from rye or bar-le y. They are next immersed in another pit filled with water; asfrstum of hark being strewed between each hide. In the course®f five or six weeks, the skins are taken out; and the water, toge-ther w ith the decayed hark, being removed, the pit is a secondl| tne filled with ooze; the hides are again macerated, with similar*frata between each, for three months. The same operation isthen repeated a third, and, after the lapse of three months, a fourth; here the hides remain for three months longer, at the expi-fation of which they are completely tanned: being thus drawnthey are suspended on poles ; when, after being compresseduy a steel-pin, they are beaten by wooden hammers, or beetles,«? fender them smooth ; and then .dried for sale. Tiie leathernown under the name of hides, is made from the skins of cows,1111 those .of lighter oxen, in the following manner; The horns are

first taken off, the hides washed and immersed in a pit full oflime-water, where they remain for a few days; after which thehair is stripped off, as above described. They now undergo vari-ous processes, similar to those already detailed, excepting that theooze is not at first of equal strength ; and that the hides are shiftedevery second or third day, for the space of six months, into astronger liquor ; being at length pul into a very rich ooze, wherethey are turned twice every week, for two or three months. Thusprepared, they are carried to another pit, with layers of bark ar-ranged between each hide ; the process being again repeated for asimilar period, when they are taken out, and treated in the samemanner as the butts. Both species of leather here described, areemployed for the soles of pumps, shoes, boots, &c. being finer orstronger, as occasion may require. The last division of leather isthat of skiiw, which includes all that is manufactured from those ofcalves, dogs, &c. They are washed in water; then plunged inlime-water, and deprived of their hair by the same operation ashides; after removing all uneven and superfluous matters, theskins are soaked in a pit of water impregnated with the dung ofpigeons, for a week or ten days, in order to extract all the parti-cles of lime, grease, &c. Next, they are treated in a similarmanner with the hides; and, in the course of five or six months,they will be sufficiently tanned. The leather thus prepared isconveyed to the currier, and fitted for the purpose of making theupper parts of boots, shoes, &c. Various methods have been triedto.render these processes less tedious and less expensive. Oak-leaves, gall-nuts, dried and pul verized heath, die harks of the birchand willow-trees, the dried anil powdered leaves of the wild laurel,and numerous other vegetable productions, have been tried, andproposed, as useful substitutes for oak-bark-: numerous experi-ments were also made with plants, by Gleditsch, Bautsch, Boh-mer, and-other writers. In 1795, Mr. William Desmond obtain-ed a patent (or practising Seguin’s method in England. He ob-tained tiie tanning principle by digesting oak-bark, or other pro-per materials in cold water, in an apparatus nearly similar to thatused in the salt-petre-works. That is, the water which has re-mained upon the powdered bark for some time, in one vessel, isdrawn ofl by a cock, anti poured upon fresh tan. This is again tohe drawn off, and poured upon other fresh tan ; and in this waythe process is to be continued to the fifth vessel. The liquor isihen highly coloured, and marks from six to eight degrees uponthe hydrometer for salts. 'This he calls the tanning lixivium.Several other patents have been granted at different times, for anaccount of winch the curious reader will consult the 1st, 3d, 6th,and 11th, vols. of the Repertory of Arts, &c. where full specifica-tions are inserted, and occasionally illustrated with plates.

TANOKE, a sea-purl-town of Hindoostan, on the coast of Ma-labar, in Calimt, 25 miles S. S. E. of Calicut . Lon. 75. 54. E.Lat. 10. 58. N.

I AN 1 AL1TE, in mineralogy, a metallic fossil of an iron-blackcolour on the external surface, hut internally between bluish-greyiiiul iron-black. It occurs imbedded in masses of the size of ahazel-nut, which have a tendency to the octahedral form. Exter-nally it is smooth and glimmering ; internally it is shining, and itslustre metallic, Specific gravity 7.95. It occurs in Sweden ,imbedded in quartz.

TANTALIUM , a metal discovered by M. Ekeberg, in themineral just mentioned; and in another named Ytrotantaiite,From eacii lie extracted, by means of the fixed alkalies, a whitepowder, which he ascertained to be the oxide of a peculiar metal;to this he gave the name of tantalium. When this oxide is power-fully heated with charcoal, it yields a button moderately hard,which, externally, has a metallic lustre, but internally it is black,and without any degree of brilliancy. The acids will again reduceit to an oxide, but they will not dissolve it. It melts before theblow-pipe with borax, or phosphate of soda, but gives no colourto either of them. Its specific gravity is about 6.5.

TANTALUS, in fabulous history, king of Phrygia and IVplilagonia, was the son of Jupiter ami the nymph' Piota. Heone day entertained the gods at bistable; when, to prove theirdivinity, he served up his son Pelops cut in pieces. All the dei-ties, exceptCeres, perceived his cruelty and impietv, and wouldnot touch his provisions. r I hat goddess inadvertently eat a partof his left shoulder. Pelops , however, was restored to life, and anivory-shoulder given him in the room of that which had been eaten;

hut.