sonorous; very malleable; but not very tenacious. Sp. gr. 7:29. Melting point 442° F. It enters into fusion with other metals; as with lead, forming pewter, and with copper, forming the various sorts of bronze, and bell-metal. TIS'SUE, Fr. tissu, woven, from tisser, to weave. 1. Cloth interwoven with gold and silver, or brilliant-coloured yarns.2. A term introduced by the French into anatomy, to express the textures which compose the different organs of animals. TITAN'IC ACID. A name for the peroxide of titanium, which exists combined with a little oxide of iron and manganese, is the mineral known by the names of TIN'AMUS, A genus of American birds TIN'AMOUS. remarkable for a very long and slender neck, covered with feathers, the tips of whose barbs are slender and slightly curled, which gives a very pecu-titanite and rutile. liar air to that part of the plumage. Order Gallinacea, Cuv. The species vary in size from that of a pheasant down to that of a quail, or even smaller. They either perch on low trees, or hide among long grass. The generic name is Latinised from the native name tinamou. TIN'CAL. A name of crude borax, as it is imported from the East Indies, in yellow greasy crystals. TINCTURE, Lat. tinctura, from tingo, to dye. A term used by apothecaries to designate a solution of any substance in dilute alcohol, or alcohol impregnated with the active principle of a vegetable or animal substance. TITANIUM. A rare metal discovered by the Rev. Mr. Gregor, in menachanite, in 1791, and by Klaproth, in red schorl, in 1795. Gregor named it menachine, from the mineral in which he discovered it, and Klaproth named it titanium, from τιτανος. The metal may most readily be continuous stream of ammoniacal gas over procured from its chloride, by passing a it. When thus prepared it is a fine powder, which, on being heated in the air, takes fire. It is sometimes observed crysstallised in small cubes, in the slag of the hearth in the great iron smelting furnaces. These crystals are very brittle, and so hard as to scratch steel. Sp. gr. 53. Traces of titanium may be discovered in many irons, wrought as well as TI'NEA. The name of a genus of nocturnal Lepidoptera. The caterpillars of the true tinea construct portable sheaths or habitations from the materials on TITHE. The tenth part of anything: which they reside. Name Tavia, a moth-appropriately the tenth part of the in worm. TIN'FOIL, from tin and folium, a leaf. Tin extended under the hammer into thin leaves. TIN-GLASS. A name of bismuth. TIN-PLATE. White iron. Thin sheetiron coated with tin. In this case the tin forms in some measure an alloy with the iron. TIN-PYRITES. A native sulphuret of tin, containing usually some copper and sometimes iron. This ore of tin is of a yellowish-gray colour, metallic lustre, and a fibrous structure. TIN-STONE. A native oxide of tin, found only in Cornwall. This is perhaps the richest ore of tin, yielding sometimes 80 per cent. of the metal. It occurs both massive and crystallised. cast. crease annually arising from the profits of land and stock, allotted to the clergy for their maintenance. Tithes are personal, when accruing from labour, art, trade, and navigation; predial when issuing from the earth; and mixed when accruing from beasts fed on the ground The term is Sax. teowa, from teogewa, a tenth. TI'THING. In law, a decennary: a company of ten householders, who, dwelling near each other, were held free pledges to the king for the good behaviour of each other. The institution of tithings in England is ascribed to Alfred. TITULAR. In ecclesiastics, a person invested with the title to a benefice. TOAD'STONE. A provincial name for a TME'SIS, from repeva, I cut. In grammar, a figure by which a compound word is separated into two parts by the interTIP'ULA. The Crane-fly: a genus of dip-vention of one or more words, as quæ mea terous insects of the family Nemocera. cunque, for quæcunque mea. The tipula of the Latins was a species of aquatic spider. The legs of the tipulæ are disproportionably long, as is well seen in the T. silvestris or Father-long-legs. TIRE. In mechanics, a band or hoop of iron, used to bind the fellies of wheels, to secure them from wearing and breaking. TIRO'NIAN NOTES. The short-hand of Roman antiquity. It variety of trap rock, found very abun- TOBACCO. The dried leaves of the Ni TIS'RI. The first Hebrew month of the civil year, and the seventh of the ecclesiastic: it answered to a part of our Sep-cotiana tabacum, a plant indigenous to tember and October. America, but which may be advanta geously cultivated in many parts of the Old World. It takes its name from Tobago, the island whence it was first brought. The green leaves possess very little odour or taste, but when dried their odour is strong and narcotic, their taste bitter and acrid. When distilled they yield an essential oil, on which their virtue depends, but which is highly poi sonous. TOC'CATA, Ital. from toccare, to touch. In music, a prelude. TOC'SIN. An old French word signifying an alarum-bell. TOD. A weight used in weighing wool. It contains 281bs. avoirdupois. TOD'DY. 1. A sweetish juice drawn from various palms in the East Indies, and which acquires intoxicating qualities by fermentation.-2. A mixture of spirits and water sweetened. TO'GA. A sort of woollen gown or mantle worn by the Romans. TOG'GEL. A small wooden pin, from four to six inches in length, and usually tapering from the middle towards the ends; used in ships instead of a hook in fixing tackle, &c. TOISE. A long measure in France equal to six French feet. To'KAY. A sort of wine produced at Tokay, in Hungary, from white grapes. It is distinguished from other wines by its aromatic taste. TO'LA. A weight for gold and silver in India. It differs in different parts. sound. Tones are distinguished into major and minor. The major tone is in the ratio of eight to nine, and results from the difference between the fourth and fifth. The tone minor is in the ratio of nine to ten, and results from the difference between the minor third and fourth. 2. In pathology, from roves, extended; the healthy and natural tension of the muscular fibre. TON'Ic. 1. In pathology, from Tosiz, of the muscles, which lasts for some time from raw, to draw. A rigid contraction without relaxation, is termed a tonic spasm.-2. In medicine, from Tovo, to strengthen. A term applied to medicines which increase the tone of the muscular fibre, and impart vigour to the system. The mineral tonics are iron, zinc, copper, arsenic, silver, bismuth, mercury, and the mineral acids. The vegetable tonics consist chiefly of bitters. TON'KA BEAN, The fruit of the DipTON'QUIN BEAN. ) terix odorata, a shrubby plant of Guiana. By digestion in alcohol it affords a crystalline volatile oil called stearoptine and coumarine by the French. This bean has a peculiarly agreeable smell, and is employed in the scenting of snuff. TON'NAGE. In commercial navigation, the number of tons which a ship can carry; also an impost on ships according to their tonnage or burden. TON'SIL, Lat. tonsilla. In anatomy, the TOLU'. Tolu balsam. A brownish-red tonsils are two oblong, sub-ovate glands, balsam, extracted from the stem of the situated on each side of the fauces, and Toluifera balsamum, a tree of South Ame-opening into the cavity of the mouth by rica, which grows in the province of Tolu. It is brought to us in little gourd-shells. See TOLUIFELA. TOLUIFFA. The generic name of the tree which affords the tolu balsam. Decandria-Monogynia. Name from tolu and fero, to yield. TOMATO. A name of Indian origin, applied to the love-apple or Solanum lycopersicum. TOMBAC'. A white alloy of copper and arsenic. TO'MENT, from tomentum, a flock of wool. A term used to designate: (1.) In anatomy, the small vessels on the surface of the brain; (2.) In botany, a species of pubescence, very soft to the touch, and giving the surface a downy appearance. TOMENTO'SE, Lat. tomentosus. Downy, woolly, cottony. Applied to stems, leaves, &c. TOM'PIONS. In gunnery, wooden cylinders put into the mouths of cannon to keep the inside dry and clean. Tox, Sax. tunna. An English weight of 20 cwt. TONE, from Tovos, sound. A modification of sound. 1. In music, an interval of a great many excretory ducts. TON'SURE, Lat. tonsura, from tonsus, shaved. In the Romish Church, (1) the first ceremony used for devoting a person to the service of God and the Church: the first degree of clericate given by a bishop, who cuts off a part of the hair, uttering prayers and benedictions. (2.) The corona or crown which priests wear as a mark of their order, and of their rank in the church. TONTINE (Fr.), from Tonti, an Italian, who invented the scheme. An annuity or survivorship; a loan raised on life annuities, with the benefit of survivorship. Thus the annuity is shared among a number, on the principle that the share of each at his death shall go to the benefit of the survivors, until at length the whole goes to the last survivor and his heirs, or to the state. TOOTH'ING. In architecture, bricks or stones left projecting at the end of a wall, that they may be bonded into a continuation of it when required. Tor. In ship-building, a sort of platform, surrounding the head of the lower mast, and projecting on all sides. serves to extend the shrouds. It TOP ARMOUR. A rail extending the width of the top of a ship, on the afterside, supported by stanchions, and equipped with a netting. TO'PAZ. A gem; different, however, from the Toradioy of the Greeks, a name derived from Topazos, an island in the Red Sea, where the ancients used to find precious stones. The topaz passes from pale wine yellow to yellowish white, greenish white, mountain green, and sky blue: from deep wine yellow into flesh red, and crimson red. Sp. gr. 3'46 to 3.64. The highly crystallised and transparent varieties are termed precious topaz. The finest varieties are obtained from the mountains of Brazil, and the Uralian Mountains; and the topaz generally occurs in primary rocks. General constituents-alumina, silica, and fluoric acid, coloured with oxide of iron. TOPAZ'OLITE, from topaz, and λ0os, stone. A pale yellow sub-variety of garnet, so named because it resembles the topaz in colour. TOP-CHAINS. Chains used in action, by which the lower yard is hung, in case the slings be shot away. TOP-CLOTH. In a ship, a large piece of canvass, used to cover the hammocks, which are lashed to the top when the ship is prepared for action. TOP-GALLANT-MAST. The mast next above the top-mast. On this are extended the top-gallant-sails. TOPH. A word originally from the Hebrew. Used, in surgery, to denote (1) a soft swelling on a bone; (2.) a concretion in the joints. It is also used, in mineralogy, to designate any calcareous deposition, resembling, in lightness of texture, the tophus, or material thrown out of volcanoes, TO'PHET. A polluted, unclean place, near Jerusalem, into which the Jews used to throw dead carcases, &c. TOP-LAN'TERN. A large lantern, placed in the after-part of a top in any ship where an admiral's flag or commodore's pendant is flying. TOP-MAST. The second division of a mast, or that part next above the lower mast. TOP'PING. In nautical language, the act of putting one extremity of a yard higher than the other. TOP PING-LIFT. A large strong tackle, employed to suspend or top the outer end of a gaff, or of the boom of a mainsail, in a brig or schooner. TOP-ROPE. In a ship, a rope to sway up a top-mast, or top-gallant-mast, to fix it in its place. TOP-SAILS. Large sails extending across the topmasts by the top-sail-yards above, and by the lower yards beneath. TOP-TACKLE. In ships, a large tackle hooked to the lower end of the topmast top-rope, and to the deck, in order to augment the mechanical power in hoisting the topmast. TOREUMATOLOGY, from rogeva, sculpture, and ygaqw, I describe. The science or art of sculpture, or a description of it. TORMENTIL'LA. Tormentil or Septfoil. A genus of indigenous perennial plants. Icosandria-Polygynia. Name, from tormentum, pain, because it was supposed to relieve pain in the teeth. There are two species; the officinal or upright, and the creeping. The root of the former is still admitted into pharmacopeias, and has been used as a substitute for bark in the process of tanning, it being a powerful' astringent. TORMEN TOR. In agriculture, an instrument something like a harrow, but supported on wheels, and each tine is furnished with a hoe or share, that enters and cuts up the ground. TORNA'DO, Sp. and Port. tornada, a return. A violent gust of wind, rising suddenly, and distinguished by its veering round all the points of the compass, like a hurricane. Tornadoes are usually accompanied by much thunder and rain, but are of short duration, and have a narrow compass. TORPE'DO. The Electric Ray, or Crampfish. A subgenus of fish of the genus Raia, Lin. Name Latin, from torpeo, to benumb, on account of the peculiarly powerful galvanic shock which the fish communicates when touched. The body is smooth, and the teeth small and sharp. It is taken on the coasts of France and England, and in the Mediterranean, in about 40 fathoms water. The space between the pectorals, head, and branchiæ is fitted on each side with a peculiar apparatus, formed of little membranous tubes, placed close together like a honeycomb, subdivided by horizontal diaphragms into small cells, filled with a sort of mucus, and traversed by numerous nerves, proceeding from the eighth pair. It is in this apparatus that resides the electric or galvanic power, which has rendered the torpedo so celebrated. TORRICEL'LIAN. Pertaining to Torricelli, an Italian philosopher, who discovered the true principle of the barometer. The tube of this instrument is named after him the Torricellian tube; and the vacuum produced in such a tube by filling it with mercury, and allowing it to descend till it is counterbalanced by atmospheric pressure, is called the Torricellian va сиит. TOR'RID. Parched: torridus, from torreo, to roast. The Torrid Zone is that broad belt of the earth included between the tropics about 23° 28′ on each side of the equator, called also the Tropical Zone. TOR'SION, from torqueo, to twist. The force of torsion is the term used by Coulomb to denote the effort made by a wire or thread which has been twisted, to untwist itself. On this principle Coulomb constructed his torsion-balance, of which the torsion-electrometer, and the torsion-galvanometer of Dr. Ritchie, are merely modifications, for particular purposes. (1.) TOR'SION-BAL'ANCE. This consists of a stand T supporting a hollow vertical rod, ST, which, in the balance of Coulomb, was of pewter, that all magnetic and electric influence might be avoided. On this rod there are two sliding-pieces, CA, and SP; the lower of which carries a plate A with a circle, divided like a dialplate, upon it; and the upper a piece P, to which the torsion wire or thread is to be fixed: N is a smail bar-piece, with a screw which clips the extremity of the wire whose torsion is to be experimented on, to which a weight, or an index, or twisted round its axis. carries a gilt ball of pith, or a disc of paper, at one extremity, which is balanced by a counterpoise at the other; d is a metallic wire, passing through the glassshade, and terminated by a metallic ball at each end. The ball of the needle, and the interior brass ball of the wire, are brought into contact by turning the index then points screw b, and the to 0 on the scale, which is marked upon the circumference of the glass. (3.) TOR'SION-GALVANOMETER. n s is the lower needle, surrounded by a coil of wire, and connected with the TORSION-ELECTROMETER. upper needle NS by a piece of straw, both, may be attached. The following are the results-1. The wire, being loaded with different weights, did not rest in the same position of the index, but in a different position, with every different weight. 2. The oscillations of the index were isochronous, whether the deflection was great or small. (2.) TOR'SION-ELECTROMETER, OF ELECTRIC-BALANCE. This consists of a thread, a b, of silk or spun glass, from which a needle of shell-lac, c, is suspended. It is attached to a screw b, by which it can be TORSION-GALVANOMETER. which passes through the upper part of the horizontal coil, and through a circular card placed above it, on which a graduated circle is drawn. It is then attached to the torsion filament, which is fixed to a screw A, supported by the frame of the instrument. The filament may be of glass, and the angle of torsion may be easily measured upon the graduated card. The wires of the coil are to be connected with the plates of the circuit by means of small mercury cups, a b. TOR'SO, Fr. torse. A name given by artists to all mutilated statues, of which The nothing remains but the trunk. term is also applied by architects to columns with twisted shafts. TORT. In law, a personal injury done to another. TOR'TOISE. All tortoises are placed in one genus, Testudo, by Linnæus, but Brongniart and others have subdivided them, chiefly according to the forms and teguments of their shell, and their feet. The land tortoises form the genus Testudo; the fresh-water tortoises, the genus Emys; and the sea tortoises, the genus Chelonia. Merrem has further distinguished by the name of Sphargis those cheloniæ whose shell is destitute of plates, and merely covered with a sort of leather. The Testudo fimbria, Gm., found in Guiana, has been placed in a subgenus, Chelys, by Dumeril; and the soft-shelled tortoises have been arranged in a genus, Trionyx, by Geoffroy. To this belongs the tyrse of Egypt; and the soft-shelled tortoise, which inhabits the Carolinas, Georgia, the Floridas, and of Guiana, so highly esteemed for its flesh. TOR'TOISE-SHELL. The yellowish-brown scales of the Testudo imbricata, Lin., a species of the tortoise, which inhabits tropical seas. It is extensively used in the manufacture of combs, snuff-boxes, &c., and in several kinds of ornamental work. It is worth in the London market from forty to sixty shillings per lb. Bulged TOR'TULOUS, Lat. tortulosus. out at intervals, like a cord having several knots on it. Applied in Natural History. To'RUS. In architecture, a large semicircular moulding, used in the bases of columns, &c. TO'TIES QUO'TIES. So often as a thing shall happen. A legal phrase. TOTIPALMA'TE, from totus, complete, and palmatus, palmate. A family of palmipede birds, remarkable for having the thumb united with the toes by one single membrane, a mode of organisation which renders their feet complete like ours. They nevertheless perch on trees. The pelican is an example. TOUCH. In naval affairs, sails are said to touch when the wind comes edgeways upon them. TOUCH-NEEDLES. Small masses of gold, silver, and copper, each pure, and in all the different combinations, proportions, and degrees of mixture, prepared for the trial of gold and silver, on the touchstone, by comparison of the mark they respectively leave on it. TOUCH'STONE. A variety of extremely compact siliceous schist, almost as close as flint, used for ascertaining the purity of gold and silver by the streak impressed on the stone by the article tried. TOUR MALINE. A mineral of the gem order, of many varieties, which occurs imbedded in granite, gneiss, mica-slate, &c., in Scotland, Sweden, Spain, France, Siberia, and many parts of America, as Massachusetts and Brazil. The fundamental form of the crystal is a rhombohedron. Lustre, vitreous; colour, brown, green, blue, red, white, frequently black, generally dark, and scarcely ever bright. Streak white. Transparent. Hardness 7 to 75. Sp. gr. 31. Constituents, silica, alumina, soda, coloured by oxide of manganese when red, and with oxide of iron when black. The green, blue, &c. varieties contain usually both these oxides. Plates, particularly of the brown tourmaline, f cut parallel to the axis, absorb one of the polarised pencils of light. The name is a corruption of the Ceylonese name tournamal. TOURNIQUET, Fr. from tourner, to turn. A surgical instrument, used for stopping the flow of blood into a limb, by compression of the main artery. Tow. (Sax.) 1. The coarse and broken part of flax or hemp, separated from the finer part by the hatchel or swingle.2. A rope. Tow'ING. Drawing a vessel forward in the water by means of a rope or tow attached to another vessel or boat. Steamvessels are often employed to tow sailing vessels up rivers, &c. TOXICOLOGY, from rozov, a poison, and λoyos, a discourse. The study of poisons, a treatise on poisons. Tox'OTES. The generic name given by Cuvier to a fish characterised like the Chatodon rostratus, by spurting water on Insects which frequent aquatic plants, to beat them down, and thereby bring them within its reach. TRABEA'TION, Lat. trabes, a beam. In architecture, the same as entablature. TRAB'ICULE, Lat. trabicula. A little beam. A term applied by anatomists to designate the thread-like processes in the longitudinal sinus of the dura mater. TRACHE'A, Teαxa. 1. The windpipe. -2. In natural history, the air-tubes of plants are by botanists called trachee, and the same term is applied by entomologists to those vessels which receive the arterial fluid, and distribute it to every |