GLU 



GOL 



them as the elementary form of vegetable 

 tissue. 



GLOBULUS. A little globe ; a round 

 deciduous shield, formed of the thallus 

 of lichens, and leaving a cavity when it 

 falls off, as in isidium. 



GLO'CHIS (7\a)xtv, a projecting point). 

 A form of hair occurring in plants, and 

 commonly called a barh ; it is forked at 

 the apex, both divisions of the fork being 

 hooked, as in the nuts of myosotis lap- 

 pula. 



GLOME'RULI (dim. of glomi, clews 

 of thread). The heaps of powdery bodies 

 which lie upon the surface of the thallus 

 of lichens. See Soredia. 



GLOME'RULUS or GLO'MUS. A 

 term applied, in inflorescence, to a clus- 

 ter of capitula enclosed in a common 

 involucre, as in echinops. It bears the 

 same relation to a capitulum as the com- 

 pound to the simple umbel. 



GLOSSO'LOGY {'^Xwaca, a tongue, 

 Xo-yop, an account). The science of 

 scientific language ; the explanation of 

 the peculiar terms employed in any 

 science. 



GLOSSOPE'TRA (7XS<r<ra, a tongue, 

 Trerpa, a rock). A term applied to the 

 fossil teeth of fishes allied to the shark, 

 occurring in the upper, secondary, and 

 tertiary strata of England, France, &c. 

 They are also called odontopetre, lamio- 

 dontes, &c. 



GLUCIC ACID {yXvKvi, sweet). An 

 acid formed by the action of a saturated 

 solution of lime or barytes on grape 

 sugar. The anhydrous acid is formed 

 from grape sugar by the loss of the ele- 

 ments of water. 



GLUCI'NA (yXvKhs, sweet). A rare 

 earth, constituting nearly 14 per cent, of 

 the emerald or beryl. Its metallic basis 

 is glucinum, a metal named in allusion 

 to the sweet taste of the salts of its oxide 

 glucina. 



GLUCO'SE (vXi/Kuf, sweet). A syn- 

 onymous term for starch sugar, diabetic 

 sugar, grape sugar, or the sugar of fruits. 



GLUME {gluma, the husk of corn). 

 A term applied to the peculiar envelope 

 of the floral apparatus in grasses, which 

 are hence called glumacece. It is a modi- 

 fication of the bract. 



GI^UME'LLE. A diminutive of (/ZMTwe, 

 and, as such, applied by De Candolle to 

 each of the bracts of grasses, situated 

 immediately within the glumes ; they are 

 commonly called palecB. A further di- 

 minutive occurs in glumellule, which the 

 same writer applies to the minute hypo- 

 153 



gynous scales situated within the glu- 

 melles or paleae, and which are also called 

 squamulcB. 



GLU'TEN (gelo, to congeal). A viscid 

 substance obtained from wheaten flour. 

 It has been separated into gliadine, or 

 vegetable albumen, and zymome, or that 

 portion of the mass with which the acid 

 that is present has united. Glutine is a 

 principle resembling gluten, but differing 

 from it in not being soluble in alcohol. 



GLY'CERIN (7\i;ku?, sweet). The 

 sweet principle of oils, also called hydrate 

 of oxide of glyceryl, the hypothetical 

 radical of glycerin. 



GLY'PTODON {fXvnro^, sculptured, 

 o6ow, a tooth). A colossal armadillo, 

 occurring in the geological period of the 

 megatheroid animals, remarkable for 

 the complicated structure of its teeth. 

 It resembled the great land tortoise, 

 whose remains are found in the Sewalik 

 hills. 



GNEISS. A term applied by the Ger- 

 man miners to a stratified primary rock, 

 composed of the same materials as gra- 

 nite, but having usually a larger propor- 

 tion of mica, and a laminated texture. 

 Three principal kinds of gneiss have been 

 distinguished — the granitic, the slaty, 

 and the laminar. 



GNO'MON {'ivuifxuivy a gnomon). In 

 every parallelogram, any of the parallelo- 

 grams about a diameter, together with the 

 complements, is called a gnomon. The 

 term gnomon also designates an upright 

 pillar, from the shadow of which the 

 ancient astronomers determined the alti- 

 tude of the sun and of the other heavenly 

 bodies. The style or index of a dial is 

 likewise termed a gnomon. 



GOBEL'S PYROPHORUS. A mix- 

 ture of charcoal and lead, in which the 

 latter is in such an extreme state of 

 division, as to take fire on exposure to 

 the air. It is formed by heating the 

 tartrate of lead in a close vessel or tube 

 to dull redness. 



GO'BIOD^ (gobius, the goby). The 

 Goby tribe ; a family of Acanthopterygious 

 fishes, distinguished by the thinness and 

 flexibility of their dorsal spines. Many 

 of them are viviparous, as the blenny. 



GOLD. A yellow metal, occurring 

 native, in a massive state, and dissemi- 

 nated in veins through rocks, or in grains 

 among the sand of rivers. Gold coin is 

 termed sterling, when it consists of 22 

 parts of gold and 2 of copper ; standard, 

 when it consists of 18 parts of gold and 

 6 of copper. 



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