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VADE MK'<:CM (so with me;. A Latin 

 phrase, used as the title of a book that is 

 very familiar and concise in its instruc- 

 tions or directions. The little hand-book, 

 brought from the Greek Enchiridion, has 

 been' of late more fashionable than Vade 

 Mecum. 



VAGAN'TES, Lat. vago, I wander. A tribe 

 of spiders, which run after aud seize their 

 prey with anility. 



VAGI'S A. Lat. sheath. The leaf-stalk of 

 those plants in which it rolls round the 

 stem. 



VA'GINATE, Lat. vaginatus. Sheathed. 



VAGINOPEN'NOCS, from vagina, asheath, 

 and penna, a wing. Sheath- winged. 



VAIR. In heraldry, a kind of fur or 

 doubling, consisting of divers little pieces, 

 argent and azure, resembling a Dutch 17 

 or a bell-glass. 



VALB'SIANS. An ancient sect of heretics. 



VALHALLA. In Scandinavian mytho- 

 logy, the palace of immortality. 



VAL'LAR CROW*. A crown bestowed, 

 among the Romans, on him who first en- 

 tered an enemy's camp. 



VAL'LUM. The trench and parapet with 

 which the Romans fortified their camps. 



VALONIA. A modern Greek name, 

 adopted in commerce for a species of acorn 

 exported from the Morea and the Levant, 

 for the use of tanners. The oak which 

 produces it is named velanida. The acorns 

 are worth, in London, from 121. to IGl. 

 a ton. 



VALVE, Lat. valree, folding-doors. 1. In 

 mechanics, a lid contrived to open one way 

 to admit a fluid, gas, steam, &c., into a 

 tube, but which shuts, when pressed from 

 the other side, to prevent the return of 

 the fluid. Valves are of various forms, as 

 hinge valves, conical valves, sliding valves, 



revolving valves, &c. 2. In anatomy, a 



kind of membrane which opens in cer- 

 tain vessels to admit the blood, and shuts 



it to prevent its regress. 3. In concho- 



logy, the shell. "When the whole shell is 

 in one piece it is called a univalve, when in 

 ;wo pieces a bivalve, and when of more 

 than two pieces, the shell is a multivalve. 



VAM'BRACE. In plate armour, a protec- 

 tion to the arm below the elbow. 



VAM'PIRE. 1. In zoology, a species of 

 large bat, the Vespertilio vampyrus, Lin., 

 called the Ternate Bat. It inhabits Gul- 

 aea, Madagascar, the East India isles, 

 Few Holland, and New Caledonia. It at 



tacks sleepini: animals, piercing a veiosfl 

 gently that they do not awake, and suck! 

 their blood. 2. The same name is some- 

 times given to a large bat of South Ame- 

 rica, the V. spectrum, Lin. 



VANA'DICM. A scarce metal, recently 

 discovered in Sweden, and thus named 

 after Vanadis (an appellation of Freya), 

 the principal female deity of ancient 

 Scandinavia. It has only as yet been ob- 

 tained from iron, and the scoriae of iron 

 furnaces, and in some of its properties 

 bears some relation to chromium, and in 

 others to uranium. 



VANE. A weathercock. In ships, a 

 piece of bunting is used for the same pur- 

 pose, and has the same name. 



VASGS. In a ship, braces to steady the 

 .mizzen-gaff. 



VANIL'LA. A Spanish name, adopted 

 in commerce, for the oblong narrow pod of 

 the Epidendrum vanilla, a species of vine, 

 extensively cultivated in Mexico, and 

 some of the warm parts of America. It is 

 aromatic, and is much used by chocolate- 

 makers, confectioners, perfumers, distil- 

 lers, &c. 



VANISHING FRACTIONS. In algebra, are 

 those fractions which, by giving a certain 

 numerical value to any variable quantity 

 which enters into them, both numerator 

 and denominator become zero, and con- 

 sequently the fraction itself becomes 



VA'POUR, IV. vapeur. 1. The state of a 

 fluid or solid rendered aeriform by appli- 

 cation of heat, and capable of being con- 

 densed or brought back to the liquid 01 

 solid state, by reducing the temperature 

 The vapour of water is particularised by 

 the name of steam (q. v.). 2. In me- 

 teorology, all substances which impair the 

 transparency of the atmosphere, are po- 

 pularly named vapours, though this term 

 is only applied technically to the invi- 

 sible and condensible product of vapor- 

 isation. 



VA'POCR-BATH. A place in which a 

 body is subjected to the steam of hot 

 water. 



VA'RIANCE. A term in laic, when there 

 is a difference of statement between two 

 material documents in a cause. 



VA'RIABL-E QUANTITIES. In mathema- 

 tics, are such quantities as are continually 

 increasing or decreasing. They are usu- 

 ally denoted by r, y, z, whereas the con- 

 sta'nt quantities are denoted by a, b, c, &e. 



VARIATION. 1. Of the compass, the de- 

 viation of the magnetic needle from its 

 parallel with the meridian, or east and 

 west of the true north and south poles. 

 2. Variation of curvature, in analyti- 

 cal geometry, is the change which takei 

 place in the curvature, in passing from 

 one point of a curve to another. 3. Va- 

 riation, in music, a difference in perform- 



