DOW 



E B O 



3. A considerable tract of elevated land, 

 generally covered with short grass. 



DO'WNY. Soft ; cottony ; nappy ; covered 

 with soft hairs. 



DRUPE, (drupes, Lat, (?pi>7rf7r?}c, Gr.) A 

 pulpy pericarp, or seed-vessel, containing 

 a single hard and bony nut, to which it is 

 attached : the epicarp and sarcocarp se- 

 parable from each other, and from the 

 endocarp, which is stony ; the nectarine, 

 peach, apricot, &c., furnish, us with fami- 

 liar examples. 



DRUPA'CEOUS. 



1. Having the characters of a drupe, as 

 drupaceous fruit. 



2. Bearing drupes, as drupaceous trees. 

 DRUSE. A hollow space in veins of ore, 



generally lined with crystals. 

 DUCT, (diictus, Lat.) A tube, canal, or 

 passage through which anything is con- 

 veyed. 



1. In anatomy the ducts are very nu- 

 merous ; thus we have the cystic duct, 

 the hepatic duct, the nasal duct, &c. &c. 



2. In botany, ducts are membranous 

 tubes, having their sides dotted or barred ; 

 they are large enough to be visible to 

 the naked eye, and are plainly seen 

 when a cane, or oak, or vine-branch, is 

 cut across. 



DU'CTILE. (ductilis, Lat. ductile, Fr. dut- 

 tile, It.) That may be drawn out into 

 greater length without breaking. The 

 term is applied to metals only, and is 

 sometimes confounded with malleable, 

 whereas the two have very different sig- 

 nifications ; thus copper is both malleable 

 and ductile, but lead is only malleable 

 and not ductile ; some metals are neither 

 malleable nor ductile, but brittle, as anti- 

 mony, manganese, tellurium, &c. &c. 



DUCTI'LITY. (ductilite, Fr. dutiilita, It.) 

 That property which metals possess of 

 being drawn out into greater length with 

 diminished thickness, without separation 

 of parts. The French used the word 

 ductilite to express malleability ; but we 

 do not. " La ductilite est un synonyme 

 de malleabilite." Diet. De L'Acad. 

 Franfoise. 



DUG. The teat or nipple. 



DU'GONG. A species of phytophagous, or 

 herbivorous, cetacea. 



DUNE. By geological writers, this word is 

 used to signify a low hill, or bank, of 

 drifted sand, and in no respect is synony- 

 mous with down, as might be inferred 

 from Todd and Webster. The downs, 

 both north and south, are very extensive 

 ranges of chalk hills, principally covered 

 with short grass, affording excellent herb- 

 age for sheep, whereas dunes are banks 

 of drifted sand, scarcely of sufficient 

 heights to be ranked as hills. 



DUODE'NUM. (duodenum, Lat. duodenum, 

 Fr.) The first of the small intestines, 

 immediately adjoining the stomach, and 

 called duodenum from its length, sup- 

 posed to be twelve inches. 



DUPLICATION, (duplicatio^ Lat. duplica- 

 tion, Fr. duplicazione, It.) A doubling, 

 or folding, of any part. 



DU'PLICATURE. Duplication. 



DUST. In botany, the pollen of the anther. 

 The pollen or dust is contained in the 

 anther. In dry and warm weather the 

 anther contracts and bursts, when the 

 pollen is thrown out. It is found, from 

 microscopic examination, that each par- 

 ticle of dust is generally a membranous 

 bag, either round or angular, smooth or 

 rough, which on meeting with any mois- 

 ture instantly bursts and discharges a 

 subtile vapour. To the perfecting the 

 seeds of plants, it is necessary that the 

 pistil, or female organ, be impregnated 

 by the pollen of the anther ; the fluid 

 contained in the pollen, when the anther 

 bursts, penetrates the stigma, and is con- 

 veyed to the seeds, whereby they are 

 rendered fertile, or endued with the pro- 

 perty of growing, and producing a plant 

 resembling the parent one. 



DYKE. See Dike. 



DY'NAMICS GEOLOGICAL. These include 

 the nature and mode of operation of all 

 kinds of physical agents, that have at any 

 time, and in any manner, affected the 

 surface and interior of the earth. Buck- 

 land's Bridgew. Treatise. 



DYSO'DILE. (from Svaw$riG,graviterolenSj 

 fcetidus, Gr.) A mineral of a greenish 

 colour found near Syracuse, which burns 

 like coal, but gives out during its com- 

 bustion a most intolerable odour. 



E 



EA'GLE-STONE. Called also cetites. A 

 variety of argillaceous iron ore, of a no- 

 dular form, something resembling a kid- 

 ney in shape, and containing a sort of 

 loose kernel. It obtained its nsme from 

 a supposition that it was either found in, 

 or had dropped from, the nests of eagles. 



EARTH'S CRUST. That portion of our 

 planet which is accessible to our observa- 

 tion and inspection. 



EBOU'LEMENT. (Fr.) Fall of any de- 

 tached rock. The fall of parts of moun- 

 tains is so common an occurrence in the 

 Alps, that it is expressively called an 



