TET 



710 



TET 



Tmus'cit-3. An ancient Roman coin, 

 ne fourth of on as. 



TERZA KIMA, It. triple rhyme. A. com- 

 plicated system of versification borrowed 

 by the early Italian poets from the Trou- 

 badours. 



TES'SBRA, from Ttftraect, four. A name 

 of the four-sided or cuboid bone. In 

 Hainan antiquities, a six-sided die, like 

 modern dice. 



TES'SCLAR. A term applied to a system 

 of crystallisation in which the form is 

 unalterable and determined, as the cube, 

 &c. 



TEST, from testor, to try. In chemistry, 

 any substance which being added to a 

 substance indicates by special characters 

 the chemical nature of that substance 

 simple or compound. Tests are usually 

 called re-agents. 



TESTA'CKA. A name given by Linn6 to 

 that order in the class vermes, wherein 

 the animals are furnished with true 

 shells: distinct from cmstacea. The shells 

 of the testaceans are carbonate of lime ; 

 those of the crustaceans are phosphate of 

 lime. Linn6 divides the testaceans into 

 36 genera, all of which are popularly 

 known as shell-fish. 



TESTACEL'LCS, Lat. testa, A genus of 

 slugs, provided with a small shell, which 

 acts as shield to the heart. 



TEST'ING. In metallurgy, the operation 

 of refining gold and silv#r. 



TES'TONE. A silver coin of Italy (Papal 

 States) worth 1*. 3|d. 



TES'TOON. A silver coin of Portugal. 

 The testoon of 1799 is worth fully six- 

 pence ; that of 1802 is worth rather less : 

 in the one case 6-jL d. ; in the other 5 ^d. 



TESTC'DO. 1. The Tortoise : a genus of 

 reptiles, comprising the terrestrial species 

 of the order chelonia. According to Linn6, 

 the genus comprised also the aquatic 

 species, which are much more numerous 

 than the land tortoises. See CHELONIA 



and TRIONYX. 2. In surgery, a meli- 



cerous tumour of the scalp, of a flattened 

 shape, fancifully supposed to resemble a 

 tortoise. 



TET'AXUS, riravo;, from mvaa, to 

 stretch. In nosology, a disease character- 

 ised by general spasmodic rigidity of the 

 muscles. 



TETRACAC'LODON. An extinct animal 

 allied to the mastodon, discovered at 

 Epplesheim in Germany. It is referable 

 to the miocene period. 



TETRA'CHORD, from nr^a, four, and 

 Xofir,, chord. A term in the ancient 

 music denoting a series of four sounds, of 

 which the extremes constitute a fourth. 



TETRADAC'TILOUS, TtTjatJaKTvAoj. 

 Having four toes. 



ji.fiom <riTot, four, and 



diap.tson (q.v.'/. Quadruple diapason or 

 octave ; a musical chord, otherwise caJled 

 a quadruple eighth or twenty-ninth. 



TETRA'DOROJJ, Gr. In ancient architec- 

 ture, a bri^k used by the Greeks in pri- 

 vate buildings, of four palms in length. 



TETRADRACHM. A silver coin of the 

 ancient Greeks four drachms. 

 TE'TRADIXAM'IA, from rt-r^/x., four, 

 and dwatiAo;, power. 

 The name of the fif- 

 teenth class of plants 

 in the Linnaean sex- 

 ual system; com- 

 prising such plants 

 as have six stamens 

 in one flower, two 

 shorter than the 

 rest, indicating the 

 superiority of four 

 stamens over the 

 other two. The or- 

 ders are: (l.)SiJtcu- 

 losa, of which cole- 

 wort is an example ; 

 (2.) Siliquosa, of 

 which the cuckoo- 

 flower and worm-seed are examples. 



TETRAfi'DROK, I 



TETRAHE'DRON, ) 

 from Tir^ct, four 

 and |Jja, a side. 

 In geometry, one 

 of the five regular 

 bodies. I? is com- 

 prehended under 

 four equilateral / \ / \ 

 and equal tri-/ \/ \ 



ansrles. It is there-' * * 



fore a pyramid. 



TETRAETE'RIS. In Grecian chronology, a 

 cycle of four years, invented by Solon to 

 make the lunar year equal to the solar. 



TET'RAGOK, from rtrja, four, and y&nict, 

 an angle. 1. In geometry, a figure having 



four angles. 2. In astrology, an aspect 



of two planets with regard to the earth, 



when they are distant from each other 



j 90, or one fourth of a circle. 



| TETRAGTN'IA, from r=ra, four, and 



! joinj, a wife. The name of an order of 



plants in several of the classes of the 



sexual system of Linnaus, consisting 



of plants" which to the classic character, 



whatever it is, add the circumstance of 



having four pistils. 



TETRAM'ETEB., from rtr$ct, four, and f&t- 

 ro, measure. A verse consisting of four 

 measures. 



TETRAS'DRIA, from r-Tja, four, and 

 oc.vr,e, a male. The name'of the fourth 

 class of plants in the sexual system of 

 Linnseus, comprising such as have for 

 stamens. The orders are: (1.) Mwtoy? 



