TDR 



730 



T CR 



metal, which Scheele first analysed. The 

 same ore has since been discovered in 

 Cornwall and in Bohemia. The base is 

 lime, and the metal combines with it in 

 the form of an acid, the tungstic acid ; a 

 yellow oxide, differing from the brown in 

 having three atoms of oxygen. Ores are 

 also found of which the bases are man- 

 ganese, lead, &c., ap. gr. of the metal 173. 

 Tungsten is insoluble in acids, and unites 

 with most other metals, but not with 

 sulphur. 



TU'NIC, Lat. ttmieti. A garment worn 

 by the Romans under the toga, next to 

 the skin. 



TC'NICARIES. A class of acephalous 

 mollusca. in Lamarck's arrangement. 

 Animal gelatinous or leathery, and co- 

 vered with a double tunic. The external 

 one distinctly organized and provided 

 with two apertures ; the interior one 

 analogous to the mantle, provided also 

 with two apertures, the one oral and the 

 other anal. These animals are found both 

 single and aggregate, fixed and floating. 



TUN'KERS or DCN'KERS. A subdivision 

 of the Baptists, chiefly in Pennsylvania. 



Trx'xEL. A subterranean passage cut 

 through hills, and sometimes under water, 

 as in the case of the Thames tunnel. 



TU'NNT. Spanish mackerel. A fish, 

 the Scomber thynnus, Lin. See THYNNUS. 



TCR'BAX. The usual head-dress of the 

 Turks.Persians, and other eastern nations. 



TBR'BID.E. A family of molluscs. Shell 

 solid and spiral ; aperture entire, closed 

 by an operculum. Order Phytophaga. 

 Named from turbo, a top. 



TCR'BINVTE, Lat. turbinatut. Of a spiral 

 oblong form. 



TURBINEI/L\. The typical genus of 

 the turbinellinse. Name dim. of turbo, a 

 top, in allusion to the form of the shell, 

 which is ponderous, smooth, or slightly 

 nodulous; spire short, papillary; pillar 

 with strong p'aits in the middle. 



TUR'SITH ROOT, ) The cortical part of 



TUR'PETH ROOT, j the Convolvulus tur- 

 pethum, brought from several parts of 

 India. Used in medicine. The name is 

 of Indian origin. 



TIR'BITH MINERAL, \ The yellow sub, 



TCR'PETH MINERAL. ) or disulphate of 

 mercury. 



TUR'BO. A genus of mollusca. Order 

 Phytophaga: family Turoida : sub- family 

 Turbines. Shell turbinate. About 160 

 species are known, of which about 70 

 are British. The periwinkle is well k nown. 



TUR'BOT. A well-known and highly 

 esteemed fish, the Pleuroncctus marimtis, 

 Lin. There are large quantities caught 

 on our coasts; yet the London market 

 is almost entirely supplied by the Dutch. 



TUR'DT-S. The thrush : a genus of pas- 

 erine birds, belonging to the family 

 Dtntirostres. Regimen frugivorous.habitt 



solitary. The name thrush is morn par- 

 ticularly applied to the ong thrush, or 

 throstle (2'. nmsiens, Lin.). The Mocking- 

 bird of North America is also a well- 

 known species. 



TURF? Sax. tyrf. 1. The upper veget- 

 able mould, with its grass and roots cut 

 into parallelograms (of about 15 inches in 

 length, 6 inches in breadth, and 3 inches 

 in thickness,) with a common spade 



used to cope dikes, &c. 2. The upper 



stratum of mossy ground, pared off with 

 a turf-spade and used for burning at 

 peats are, but regarded as inferior. 



TUR'KET-RED. A brilliant red dye pro- 

 duced on cotton by madder. 



TUR'LCPINS. In French ecclesiastical 

 history, one of the numerous by-names 

 by which the sectaries of the 14th cen- 

 tury were distinguished. 



TUR'MERIC. Indian saffron. The root 

 of the Curcuma loiiga, brought from Ben- 

 gal, Java, China, &c. It is used in dye- 

 ing, affording a beautiful yellow, which 

 however is extremely fugitive. 



TCR'MERITE. A rare mineral, consist- 

 ing of alumina, lime, and magnesia, 

 coloured yellow by oxide of iron. It is 

 so named because its colour approaches 

 to the yellow of turmeric. 



TURN'-PL.VTE, ) On railways, a contri- 



TURN'-TABLE. j vance for removing car- 

 riages from one line of rails to another. 

 It is composed of an iron framing, upon 

 which iron grating or wood planking is 

 laid, thereby forming a table or platform, 

 two pair of rails being fixed to the upper 

 surface, crossing each other at right 

 angles, and of corresponding gauge with 

 those laid down upon the line. The plat- 

 form is further made to turn upon a 

 centre pivot, which rests upon another 

 iron framing set in masonry. 



TURNIP. 1. A well-known tuberous 

 plant, the Brassicn rapa, of which there 



are several varieties. 2. The Swedish 



turnip is the Ruta baga. 



TURS'SOLB. Heliotrope. See HELIO- 

 TROPIUM. 



TCR'PESTIXE, Lat. tere.binthina ; Fr. 

 terebenthine ; Ger. turpenthin. A resinous 

 substance, obtained by making incisions 

 in the steins of several species of pines. 

 The common turpentine is obtained from 

 Pinus sylrestris, or Scotch fir ; the Venice 

 turpentine from the Pinus larii, or larch ; 

 the Candian turpentine or balsam from 

 the PIMM* balsamea, or balsam pine of the 

 cold parts of North America ; the Chian or 

 Cyprus turpentine is got from the Pistacia 

 terebinthus, which is cultivated in Chios 

 and Cyprus, and grows only in warm cli- 

 mates. All the turpentines dissolve in 

 rectified spirits or pure alcohol, and by 

 distillation give similar oils, which, from 

 their being procured by distillation, art 

 called spirits of turpentine. If the distil- 



