GUL 



stratum of the air, causes asphyxia in 

 animals introduced into it. ^ 



GROUND BASE. In Music, a base! 

 consisting of a very few bars, which arel 

 continually repeated during the whol4 

 movement. 



GRU'IDiE {grus, a crane). A family 

 of wading birds, named from the genus 

 grus. 



GRUMOUS {grumus, a clot). Knotted ; 

 collected into granular masses, as the 

 fecula in the stem of the Sago palm. 



GRUS. The Crane ; a southern 

 constellation consisting of fourteen 

 stars. 



GRY'LLIDiE {gryllus, a grasshopper). 

 The Grasshopper tribe ; a group of or- 

 thopterous insects, belonging to the tribe 

 saltatoria, and distinguished by the roof- 

 like position of the elytra, or wing-cases, 

 when these are closed. 



GRYPHiE'A. A genus of bivalves, 

 allied to the oyster, and found abundantly 

 in the secondary strata of Europe from 

 the lias upwards to the chalk, but scarcely 

 known in the tertiary strata. 



GRY'PHITE LIMESTONE. A de- 

 signation of the Lias formation, from the 

 numerous shells of the genus gryphcea 

 which it contains. 



GUANO. A manure employed in 

 South America, consisting of urate of 

 ammonia and other ammoniacal salts. 

 It appears to consist of the excrements 

 of sea- fowl. 



GUIA'NA CURRENT. A branch, or 

 rather a continuation, of the great equa- 

 torial current, running from Cape St. 

 Roque in Brazil to the Island of Trini- 

 dad, along the low co^st of Guiana, and 

 at no great distance from it, and lost in 

 the Caribbean sea. Its whole course ex- 

 tends to about 2500 nautical miles. See 

 Brazil Current. 



GUINEA, or NORTH AFRICAN 

 CURRENT. A current in the North 

 Atlantic, which has its origin in the sea 

 between the southern coast of Ireland 

 and Cape Finisterre in Spain, and ranges 

 along the coast of Guinea. Near its ori- 

 gin, a branch, called RennelVs Current, 

 separates itself from the main stream, 

 and performs a complete rotation be- 

 tween Spain, France, and the Atlantic 

 at largp. 



GULF. A portion of the ocean running 

 up into the land between two promon- 

 tories, and spreading out info a capacious 

 bay. A hay (bow) is a projection of the 

 ocean into the land, but is not necessarily 

 a gulf, which includes the idea of a sort 

 157 



1 



GYM 



of abyss where the waters are engulfed^ 

 or swallowed up. 



GULF STREAM. The name given 

 by navigators to that current of the 

 Atlantic, which traverses the sea between 

 the parallels of 36° and 44° in the northern 

 hemisphere. It enters the gulf of Mexico, 

 through the strait formed by the western 

 end of Cuba and the opposite peninsula, 

 follows the bendings of the Mexican 

 coast, and flows into the gulf of Florida. ^ 

 ~ GrUMr Tegetable"' mucilage; a CDTn=~*~** 

 mon proximate principle of plants. Gum- 

 resins are the concrete juices of certain 

 plants, consisting of resin, gum, essential 

 oil, and extractive matter. 



GUNPOWDER. An explosive mix- 

 ture of five parts of nitre, one of sulphur, 

 and one of charcoal, finely powdered, and 

 very accurately blended. The grains are 

 smoothed by friction, and are then said 

 to be glazed. 



GUNTER'S LINE. A logarithmic 

 line engraved on scales, sectors, &c., for 

 facilitating the multiplication and divi- 

 sion of numbers. The numbers are 

 usually drawn upon two separate rules, 

 which slide against each other. See Scale. 



GURHO'FFITE. Compact dolomite, 

 occurring in serpentine rocks in Lower 

 Austria. 



GUTTA PERCHA. A substance con- 

 tained in the sap of a tree belonging to 

 the natural order Sapotacecs, abounding 

 in the island of Singapore and in the 

 Malayan peninsula. It is plentiful in 

 Sarawak, where it is called Niato, and is 

 probably to be found over the whole 

 island of Borneo. The substance, as an 

 article of commerce, appears likely to 

 rival caoutchouc in its application to the 

 useful and ornamental arts. 



GUTTIFERiE {gutta, a drop, fero, to 

 bear). The Mangosteen tribe of Dico- 

 tyledonous plants. Trees or shrubs, oc- 

 casionally parasitical, yielding resinous 

 juice; leaves entire, opposite; flowers 

 polypetalous ; stamens hypogynous ; car- 

 pels concrete ; ovary consisting of several 

 cells. 



GYMNOCA'RPOUS (yvuvoi, naked, 

 KapTTor. fruit). A term applied to a class 

 of fruits in the arrangement of Mirbel, 

 in which the fruit is not disguised by the 

 adherence of any other organ than the 

 calyx. See Angeiocarpous. 



GYMNODO'NTES (-^vtivo^, naked, 

 obov<:, a tooth). A family of the plecto- 

 gnathous fishes, including the spinous 

 globe-fishes, in which the jaws are co- 

 vered with a substance resembling ivory, 



f 



