GLY 



GNE 



the resemblance in its properties to the 

 animal principle formerly called gluten, 

 but now described under the term FIBRIK, 

 (which see,) it has received the name of 

 vegetable gluten. It is obtained in largest 

 quantities from wheat, amounting to the 

 twelfth part of the whole grain, by knead- 

 ing the flower into paste, which is to be 

 washed very cautiously, by kneading it 

 under a jet of water, till the water carries 

 off' nothing more, but runs off co-.. 

 lourless; what remains is gluten: it is 

 ductile and elastic ; it has some resem- 

 blance to animal tendon or membrane : it 

 is very tenacious, and may be used as a 

 cement for broken porcelain vessels. It 

 has a peculiar smell, with scarcely any 

 taste. When exposed to the air it as- 

 sumes a brown colour, and becomes ap- 

 parently covered with a coat of oil. When 

 completely dry it resembles glue, and 

 breaks like glass. It is insoluble in water, 

 alcohol, and ether ; but the acids dissolve 

 it, and the alkalies precipitate it. It has 

 a strong affinity for the colouring matter 

 of vegetables, and likewise for resinous 

 substances. When kept moist it ferments, 

 and emits a very offensive smell ; the 

 vapour blackens silver and lead. Its con- 

 stituent parts are oxygen, hydrogen, car- 

 bon, and azote. It exists, as we have ob- 

 served, most abundantly in wheat, but it 

 is found in large quantities in many other 

 plants. It is gluten that renders wheat so 

 useful in the art of bread making. 



GLYCINE, in botany, a genus of the 

 Diadelphia Decandria class and order. 

 Natural order of Papilionaceae, or Legu- 

 minosae. Essential character : calyx two- 

 lipped ; corolla the keel turning back, the 

 banner at the tip. There are twenty -five 

 species. There are eleven species enu- 

 merated by Muhlenberg, as natives of the 

 United States, and a twelfth was discover- 

 ed by Dr. W. P. C. Barton, professor of 

 botany in the University of Pennsylvania, 

 viz. G. parabolica. It is described by him 

 in his Prodromus Flora Philadelphica. 



GLYCYRRHIZA, in botany, English 

 Kquorice,a, genus of the Diadelphia Decan- 

 dria class and order. Natural order of 

 Papilionacese, or Legvrminosae. Essen- 

 tial character: calyx two-lipped, upper- 

 lip three-parted, lower undivided; le- 

 gume ovate, compressed. There are four 

 species. These are tall growing peren- 

 nial, herbaceous plants, with the stalk 

 somewhat woody at bottom. The stipules 

 are distinct from the petiole ; the flowers 

 in a head or spike from the axils and at 

 the ends of the branches ; seed vessel a 

 legume or pod, smooth, hairy, or prickly. 



GLYPH, in sculpture and architecture, 

 denotes any canal or cavity, used as an. 

 ornament. 



CLYSTER, or CLYSTER, among physi- 

 cians. See CLYSTER. 



GMELINA, in botany, so called in ho- 

 nour of Joh. George Gmelin, professor of 

 natural history at St. Petersburgh, after- 

 wards of botany at Tubingen, a genus of 

 the Didynamia Angiospermia class and 

 order. Natural order of Personatse. Vi- 

 tices, Jussieu. Essential character : calyx 

 slightly four-toothed; corolla four-cleft, 

 bell-shaped; anthers two parted, two 

 simple ; drupe with a two or three-exiled 

 nut. There is but one species, viz. G. 

 asiatica. 



GNAPHALIUM, in botany, a genus of 

 the Syngenesia Polygamia Superflua class 

 and order. Natural order of Composite 

 Discoideae. Corymbiferse, Jussieu. Essen- 

 tial character : calyx imbricate, with the 

 marginal scales rounded, scariose, colour- 

 ed ; down feathered ; receptacle naked. 

 There are sixty-six species : the nume- 

 rous species of this genus are chiefly un- 

 der shrubs or herbs ; the leaves are alter- 

 nately placed, generally hoary ; the flow- 

 ers usually terminate the stem and 

 branches in globes or corymbs. The 

 calyx is permanent, with yellow or white 

 scales. There are nine American species. 



GNAT. See CULEX. 



GNEISS, in mineralogy, is composed 

 principally of felspar, quartz, and mica, 

 forming plates, laid on each other, and se- 

 parated by thin layers of mica. It differs 

 from granite by being shistose ; though, 

 like that, it sometimes contains shorl and 

 garnet. The beds of gneiss sometimes 

 alternate with layers of granular lime- 

 stones, shistose, hornblende, and porphy- 

 ry. It is rich in ores, almost every metal 

 has been found in gneiss rocks, either in 

 veins or beds. Mr. Jameson mentions 

 four kinds of gneiss : 1. That which ap- 

 proaches to the granular structure. 2. 

 The waved or undulated. 3. The com- 

 mon ; and, 4. The thin slaty ; and he 

 says the order of their transition is also 

 that of their relative antiquity,consequent- 

 ly the more granular the structure, the 

 older the rock ; and, on the contrary, the 

 more slaty, the newer it is. In the last 

 member of the series is the smallest por- 

 tian of felspar, and largest of mica ; hence 

 its texture is more completely slaty than 

 that of any of the others. The other ex- 

 tremity contains much felspar, and but 

 little mica. The common contains a 

 nearly equal quantity of felspar and 

 quartz. 



