five parts of double-refined sugar, and three parts of filtered lemon juice be incorporated, so as to form a syrup. The juices of mulberries, raspberries, and black currants, may be converted into syrup in a similar manner: they are all cooling, pleasant liquids, and may be advantageously employed for mitigating thirst in bilious, or inflammatory disorders; and also for gargling the fauces, in cases of inflammation of the mouth and tonsils. TAL T. TACAMAHACA, a gummyresinous substance, obtained from the Carolina POPLAR. The best sort is collected from the fruit of the tree, in gourd-shells: it is somewhat soft and unctuous, of a pale-green, or yellowish colour, and a fragrant odour, resembling that of amber-grease, or lavender. The drug commonly met with in the shops, consists of variegated semi-transparent grains, procured from the sap exuding through incisions made in the poplar; and which are greatly inferior to the genuine species. Tacamahaca is chiefly employed externally, for discussing tumors, promoting their maturation, and mitigating pains in the limbs; though the finer sort may be advantageously used for the same purposes, as other balsamics. TALC, a species of fossil, found in England, Bohemia, Spain, &c. comprehending three varieties, namely: 1. The Talcite, or Scaly Talc, is dug in small light scales, which adhere to the fingers: it is white, TAL intermixed with green; and, when rubbed on the skin, imparts a bright gloss. 2. The Venetian, or Common Talc, is also white, interspersed with green or red veins. 3. The Schistose Talc is of a slaty nature, and a grey hue, spotted with white, green, or blue; but, on exposure to the air, it becomes white and scaly. This mineral is employed in preparing compositions for earthen vessels: on account of its smoothness, brightness, and unctuous quality, it has been celebrated as a cosmetic; and various unsuccessful experiments have been made, with a view to extract from it oils, salts, and other supposed ingredients.... When combined with alkaline salts, it is fusible in a strong heat, and forms a transparent, handsome, greenish-yellow glass : if equal portions of talc and of chalk be melted together with onefourth part of borax, the mixture will produce a fine pellucid greenish glass, which is of considerable lustre and hardness: gypsous earths may also with advantage be substituted for the chalk, and the result will be a beautiful, pellucid yellow glass, of equal brightness and durability. TANNING, is the art of preparing leather from raw skins and hides, so as to render it more pliant and durable. The processes employed for this purpose, are various; every tanner adopting some peculiar method: we have therefore selected the following, which is practised with little difference, in the metropolis and its vicinity; where the leather is divided into three sorts, known under the names of backs, or butts, hides, and skins. The strongest hides are selected for the butts; and, after being divested of the horns, they are laid in heaps for one or two days during the summer, and for the space of five or six, in the winter. Next, they are suspended on poles in a smoke-house, or room containing a fire, made of wet tan, to induce a slight degree of putrefaction, so that the hair may be stripped off; an object which is effected by spreading such hides on a wooden horse, and scraping them with a curved knife. They are then immersed in water, to be cleansed from all dirt, and extended a second time on the horse, when all extraneous matters must be carefully removed. The hides are now steeped in a pit containing ouze, or a strong liquor, prepared by infusing ground oak-bark in water; after which they are plunged into another pit, containing water powerfully impregnated with oil of vitriol, or with an acid obtained from rye or barley. They are next immersed in another pit filled with water; a stratum of bark being strewed between each hide. In the course of five or six weeks, the skins are taken out; and the water together with the decayed bark, being removed, the pit is a second time filled with ooze; the hides are again macerated, with similar strata between each, for three months. The same operation is then repeated a third, and, after the lapse of three months, a fourth time: here the hides remain for three months longer, at the expiration of which they are completely tanned; being thus drawn out, they are suspended on poles; when, after being compressed by a steel pin, they are beaten by wooden hammers, or beetles, to render them smooth; and then dried for sale. The leather known under the name of hides, is made from the skins of cows, and those of lighter oxen, in the following manner: The horns are first taken off, the hides washed and immersed in a pit full of lime-water, where they remain for a few days; after which the hair is stripped off, as above described. They now undergo various processes, similar to those already detailed, excepting that the ooze is not at first of equal strength; and that the hides are shifted every second or third day, for the space of six months, into a stronger liquor; being at length put into a very rich ooze, where they are turned twice every week, for two or three months. Thus prepared, they are carried to another pit, with layers of bark arranged between each hide; the process being again repeated for a similar period, when they are taken out, and treated in the same manner as the butts. Both species of leather here described, are employed for the soles of pumps, shoes, boots, &c.; being finer or stronger, as occasion may require. The last division of leather is that of skins, which includes all that is Manufactured from those of calves, dogs, &c. They are washed in water: then plunged in limewater, and deprived of their hair by the same operation as hides; after removing all uneven and superfluous matters, the skins are soaked in a pit of water impregnated with the dung of pigeons, for a week or ten days, in order to extract all the particles of lime, grease, &c. Next, they are treated in a similar manner with the hides; and, in the course of five or six months, they will be sufficiently tanned.....The leather thus prepared, is now conveyed to the currier; and, after undergoing the process detailed, vol. ii. p. 299, it is used for the upper parts of boots, shoes, &c. Such are the old methods commonly practised in tanning: these, however, being too tedious and expensive, various expedients have lately been devised, with a view to shorten the respective processes, and to procure substitutes for oakbark. Thus Dr. MACзRIDE proposed the use of vitriolic acid, instead of that obtained from vegetables; which, having been found very serviceable for distending the pores of the skins intended for butts, has been generally adopted by tanners; as it improves the leather in point of durability; and at the same time tends to facilitate or simplify the operations. He also recommended lime-water to be Substituted for the common fluid, to promote the extraction of the astringent matter from the oakbark; but, the former being very powerful, and apt to injure the tex VOL. V. ture of the leather, it is seldom employed. [Mr. SEGUIN has proved, that in the water impregnated with the soluble parts of tan, there are two very distinct and different substances: the one which precipitates a black matter from iron, is the gallic acid or principle; the other, which precipitates animal gelatin or glue, is called the tanning principle, on account of its efficacy in the preparation of leather. This discovery enables us to ascertain the presence of the tanning principle in any substance immediately; for every substance of which the infusion is capable of precipitating animal gelatin, possesses it. Theexperiments of Mr. BIGGIN, (London Philosop. Trans. 1799,) shew, that similar barks, when taken from trees at different seasons, differ as to the quantities of tannen they contain, and Mr. DAVY observed, that the properties of the astringent principle in barks, vary considerably according as their age and size are different; besides, these proportions are often influenced by accidental circumstances, so that it is very difficult to ascertain their distinct relations to each other. Mr. DAVY, (Trans. Royal Soc. Lon. 1803.) is of opinion, "that as lime and pot-ash form compounds with tannen, which are not decomposable by gelatin, it follows that their effect must be highly pernicious, and that there is very little reason to suppose, that any bodies will be found, which, at the same time that they increase the solubility of tannen in water, will not likewise diminish its attraction for skin.” Dr. MACBRIDE's recommendation therefore of lime, does not appear judicious, and the excellent hint of N Mr. DAVY should be carefully attended to by all who make experiments upon tanning. From some late experiments by Dr. G. WILKINSON, it appears, that the bark of the broad-leaved willow, (salix latifolia) possesses the astringent or tanning principle in a very large proportion (see TORMENTIL) and that the nitric acid acts more powerfully on vegetables containing tan, than either the sulphuric or muriatic acids: the former of which, according to Dr. WILLICH, is used by the London tanners. See, Experiments and observations on the Cortex salicis Latifolia, or broad-leafed willow bark, by Dr. WILKINSON, New Castle upon Tyne, 1803, 48. 6d.] Oak-leaves, gall-nuts, dried and pulverized heath, the barks of the birch and willow-trees, the dried and powdered leaves of the wild laurel, and numerous other vegetable productions, have been tried, and proposed, as useful substitutes for oak-bark: numerous experiments were also made with plants, by GLEDITSCH, BAUTSCH, BONMER, and other writers; but, as we state the results of these in the progress of our work, it remains only to mention the following patents, among the multitude granted at different periods; namely: 1. The privilege obtained by Mr. SAMUEL ASHTON, in January, 1794, for his new method of tanning..... 2. Mr. JOHN TUCKER'S patent, dated in May, 1795, for a mode of tanning and making leather in a much shorter period, and of a superior quality, than can be effected by the common method......3. Mr. WILLIAM DESMOND's in January, 1796; for a process communicated to him (by Mr. SEGUIN), of tanning hides, &c. by rendering them more solid and incorruptible in water.....4. Mr. ROBERT CROSS'S, in April, 1797, for a tan-pit on a new construction, and a method of tanning in one-half of the usual time, &c...........5. Mr. FRANCIS BREWIN's, in June, 1799, for an improved process of tanning hides and skins.....As the specification ofthese patents, however intersting to the tanner, are partly too diffuse, and partly of such nature as not to admit of abridgment, the curious reader will consult the 1st, 3d, 6th, and 11th vols. of the Repertory of Arts, &c. where full specifications are inserted, and occasionally illustrated with plates.....See also CURRYING, HIDES, LEATHER, SKINS, &c. TANSY, the COMMON, or Tanacetum vulgare, L. an indigenous perennial, growing in elevated meadows and pastures, on the banks of rivers, and in swampy situations; flowering in the month of June. This plant possesses a warm, bitter taste; it is deobstruent, not ungrateful to the palate; and may be used as a substitute for hops.... The tender leaves are sometimes employed to impart a colour and flavour to puddings: according to Dr. WITHERING, its seeds are an excellent vermifuge; and, if any animal substance be rubbed with this herb, it will be effectually preserved from the attacks of the flesh-fly......Tansy-tea is recommended as a preventive of the gout.....From the expressed juice of this vegetable, the Finlanders obtain a green dye.....The plant is eaten by cows and sheep, but refused by horses, goats, and hogs. [TAP-COCK. A very ingenious contrivance to prevent the necessity of a vent-peg, in a beer or cyder barrel, was lately invented general, such as nausea; vomiting; by Mr. ROBERT HARE, Jun. of giddiness; indigestion; colic; and Philadelphia. It has two perfo- flatulence: the patient feels a presFations, one for the admission of sure in certain parts of the abdoair, commencing at the point of men which, on shifting its place, insertion in the cask, and termi- mostly produces a chilling sensanating at the top of the key; an- tion in the lower belly, or in the other for the emission of the fluid, back. A more certain, and incommencing at the same point, deed the only criterion is, the exand proceeding to the nozle in a pulsion of one or more pieces of direction nearly similar to that of the worm itself. the instrument in ordinary use..... By this highly useful economical invention, vast quantities of liquor which are annually made sour or vapid by the careless omission of the vent-peg of barrels, will be preserved from acidity, and in their original briskness. The editor has a pleasure in being able to say, that the inventor is about taking measures to bring this excellent Tap-cock into general use; and that a more full account, illustrated by engravings, will be found in the 6th vol. of the American Phil. Trans. now in the press by Miss AIKIN.] Cure:..... An extraordinary number of remedies have been suggested, and tried, with various success: nor can such diversity of effects appear surprising, if the difficulty of expelling the tapeworm be considered; as, in the attempt, portions are frequently broken off and discharged: Nature having endowed this monster with a power of regeneration, it soon acquires its former size, and excites the same turbulent motions, We shall, therefore, state only those remedies which appear to be the most efficacious. 1. The celebrated specific of Mad. NOUFFER, was purchased, and published, by the King of France.....[For a notice of which See FERN.] 2. The method of carrying off TAPE-WORM, or Taenia, is one of the most tormenting worms, breeding in the bowels of the lower animals, as well as of mankind, and consisting of several species, namely; the armed and un- the tape-worm, recommended by armed; the long and short-limbed, or broad tape-worm; but that most frequently occurring in Britain, is the solium, which moves about, and has a regular round head, resembling a wart. It is from one, to twenty yards and upwards in length; the body is composed of a number of articulated rings, or joints, by which it attaches itself to the membranes of the intes tines. The symptoms by which the presence of this creature may be ascertained, are those of worms in HERRENSCHWANDT, is as follows: The patient must swallow one dram of the male fern two successive mornings, before breakfast; and, in the evening, two hours after a light supper. On the third morning, the following powder is likewise to be taken before breakfast, and followed by large potions of weak tea: Take of purified gamboge, 12 grains; salt of wormwood 20 grains, and STARKEY'S soap (a composition of distilled oil and fixed vegetable alkali) 2 grains; the whole to be duly incorporat |