DEFINITION OF TERMS. 



139 



DEFINITION OP TERSIS. 



Letter G. 



Galbanum, a gum issuing from the 

 stem of an umbelliferous plant, growing 

 in Persia, and many parts of Africa. 



It is inflammable in the manner of a 

 resin, and soluble in water like a gum. 



It attenuates arid dissolves tough 

 phlegm, and is therefore of service in 

 asthmas, and inveterate coughs, and in 

 many other complaints. 



Galenic, or Galenical, in Pharmacy, 

 a manner of treating diseases. Galenical 

 medicines are those which are formed by 

 the easier preparation of herbs, roots, &c., 

 by infusion, decoction, &c., and by com- 

 bining and multiplying ingredients; while 

 those oi chemistry draw their more inti- 

 mate and remote virtues by means of 

 fire, and elaborate preparations, as calci- 

 nation, digestion, fermentation, &c. 



Gall, in natural history, denotes any 

 protuberance or tumor produced' by the 

 puncture of insects on plants and trees of 

 different kinds. 



Galvanism, a term used to denote the 

 influence of metals by mere contact with 

 the animal body. It has been long as- 

 serted that when porter, (and some other 

 liquors also) is drunk out of a pewter pot, 

 it has a taste different from what it has 

 when drunk out of glass or earthen ware. 



Gas, among chemists, a term used to 

 denote all the aerial and permanently elas- 

 tic fluids except atmospheric air. 



Gastric Juice, among physicians, a 

 thin pelucid, spumous, and saltish liquor, 

 which continually distils from the glands 

 of the stomach, for the dilution of the 

 food. 



Gelatine, in chemistry, a jelly, pro- 

 duced from animal substances by frequent 

 washings in cold water; glue, size, and 

 isinglass, are all composed, in part, of 

 this substance. 



Gelatine exists in great abundance in 

 animals; forming the constituent part of 

 their solid and fluid parts; its uses are 

 numerous. In a state of jelly, it consti- 

 tutes one of the most nourishing and pa- 

 latable species of food. 



Gelatinous, in pharmacy and medi- 

 cine, any thing approaching to the gluti- 

 nous consistence of jelly. 



Gem, in natural history, a common 



name for all precious stones, of which 

 there are two classes, the pellucid and 

 semi-pellucid. 



The bodies composing the class of pel- 

 lucid gems, are bright, elegant, and beau- 

 tiful fossils, naturally and essentially com- 

 pound, ever found in detached masses, 

 extremely hard, and of great lustre. 



The bodies composing the class of 

 semi-pellucid gems, are stones, naturally 

 and essentially compound, not inflammable, 

 nor soluble in water; found in detatched 

 masses, and composed of crystalline mat- 

 ter, debased by earths; however, they 

 are but slightly debased, and are of great 

 beauty and brightness, of a moderate de- 

 gree of transparency, and are usually 

 found in small masses. 



The knowledge of gems depends prin- 

 cipally on observing their hardness and 

 color. For hardness, they are commonly 

 allowed to stand in the following order; 

 the diamond the hardest of all; then the 

 ruby, sapphire, hyacinth, emerald, ame- 

 thyst, garnet, carneol, chalcedony, onyx, 

 jasper, agate, porphyry, and marble. In 

 point of color the diamond is valued for 

 its transparency, the ruby for its purple, 

 the sapphire for its blue, the emerald for 

 its green, the hyacinth for its orange, the 

 amethyst for its violet, the carneol for its 

 carnation, the onyx for its tawny, the 

 jasper, agate, and porphyry for their ver- 

 million, green, and variegated colors, and 

 the garnet for its transparent blood-red. 



Ge03Ietry, the science and doctrine 

 of local extension, as of lines, surfaces, 

 and solids, with that of ratios, &c. 



The usefulness of this science extends 

 to almost every artand science. It is by 

 the help of it that engineers conduct all 

 their works. On geometry, likewise, 

 depends the theory of music, optics, per- 

 spective, drawing, mechanics, hydraulics, 

 pneumatics, &c. 



Germination, in botany. When a 

 seed is placed, in a situation favorable to 

 vegetation, it very soon changes its ap- 

 pearance. The radicle is converted into 

 a root, and sinks into the earth; the 

 plumula, on the other hand, rises above 

 the earth, and becomes the trunk or stem. 



When these changes take place, the 

 seed is said to germinate. The process 

 itself has been called germination, which 



