UNO 



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V E G 



UNO'RGANIZED. Having no parts instru- 

 mental to the motion or nourishment of 

 the rest. 



UNO'XIDATED. }Not converted into an 



UNO'XIDISED. J oxide by combination 

 with oxygen. 



UNOXY'GENATED. Not combined with 

 oxygen. 



UNSTRA'TIFIED. A term applied to rocks 

 that are not stratified, or not arranged in 

 strata. Mr. De La Beche observes, " the 

 terms stratified and unstratified have been 

 commonly considered as respectively sy- 

 nonymous with aqueous and igneous. 

 Practically, this division is highly valua- 

 ble ; but theoretically, it is not so satis- 

 factory, at least, if we are to infer that all 

 rocks divided into tabular masses, one 

 resting on another, must have been de- 

 posited either chemically or mechanically 

 from water. We should be careful not 

 to couple too far stratification with 

 aqueous deposition, as sheets of igneous 

 rocks may cover pre-existing sheets of 

 similar rocks, and the result be stratifi- 

 cation. 1 ' 



UPHEA/VED. Lifted up by some expansive 

 or elevating power from below. 



U'PPER TE'RTJARY STRA'TA. These strata 

 are considered to be of more recent origin 

 than those usually denominated tertiary, 

 and, by some geologists, have been termed 

 quaternary. They are supposed to be of 

 more recent origin than any of the strata 



composing the formations of the London 

 and Paris basins. 



U'RANITE. An ore of Uranium of a black 

 or green colour, called also Pechblende. 



URA'NIUM. (Thus named by Klaproth, 

 who discovered it in 1789.) A metallic 

 substance of a grey colour, obtained with 

 great difficulty from a mineral called 

 pechblende. It is infusible. Specific 

 gravity 9*0. It is found in Saxony and 

 Cornwall. It imparts a deep orange 

 colour to the enamel of porcelain. Little 

 however is known of its properties, nor is 

 it much used, in consequence of the ex- 

 treme difficulty that exists in obtaining it. 



U'RCEOLATE. (from urceolus, Lat. a water- 

 pitcher.) 



1. In conchology, a term applied to a 

 shell that swells in the middle, and is 

 therefore supposed to bear a resemblance 

 to a water-pitcher. 



2. In botany, applied to a calyx or corolla 

 swelling out like a pitcher. 



U'RCHIN. (erinaceus, Lat.) The hedge- 

 hog. The name of sea urchin has been 

 given to the echinus. 



U'TRICLE. (utriculus, Lat, a little bottle.) 

 In botany, a term applied to a species of 

 capsule resembling a small bladder, or 

 capsule of one cell, which never opens by 

 valves, and drops with the seed. It is 

 thin and transparent, and is more fre- 

 quently considered to be the external coat 

 of the seed than a real capsule. 



V 



VA'GINATED. (from vagina, a sheath, Lat.) 

 A term used in botany, sheathed. 



VAGINOPE'NNOUS. (from vagina, a sheath, 

 andj^enwa, awing, Lat.) Sheath-winged; 

 having the wings covered with hard cases. 



VAGINU'LA. A genus of minute pyramidal 

 shells, known only as fossils, and found 

 in the tertiary strata near Bordeaux. 



VALVA'TA. A genus of small freshwater 

 univalves belonging to the family Peristo- 

 mata. Valvatse are found both recent 

 and fossil. Dr. Mantell mentions one 

 species, Valvata piscinalis, as occurring 

 in the alluvial deposits of Sussex. 



VALVE, (valva, Lat. valve, Fr. valva, It.) 



1. In conchology, the shell. When the 

 whole shell of the animal is in one piece, 

 it is called an univalve ; when there are 

 two shells, or the shelly covering consists 

 of two pieces, as in the oyster, muscle, 

 &c., they are called bivalves ; and when 

 the covering consists of more than two 

 pieces, multivalves. 



2. In anatomy, a folding door or lid at- 

 tached to a hollow vessel by means of a 



hinge, which allows the valve to open in 

 one direction only for the passage of 

 fluids, and prevents their retrograde mo- 

 tion, or regurgitation. Thus there are 

 valves in the heart ; valves in the veins ; 

 valves in the lymphatics, &c. 



VANA'DIUM. A metal recently discovered 

 in Sweden, and thus named after Vanadis, 

 a Scandinavian deity. Its properties are 

 not yet known. 



VARIE'TY. (varietas, Lat. variete, Fr. 

 varieta, It.) A subdivision of species, 

 arising from accidental, or unimportant 

 and trifling, differences. 



VARI'OHTE. (from variola, Lat.) The 

 name given to an amygdaloidal or por- 

 phyritic rock, merely in consequence of 

 its spotted appearance. 



VA'SCULAR. (from vasculvm, Lat. a littte 

 vessel; vasculaire,~Fr.) Containing ves- 

 sels or tubes ; full of vessels within which 

 the fluids are confined, and by which their 

 course and their velocity are regulated. 



VE'GETABLES. The first appearance of 

 vegetable existence may be discovered in 



