of Johnson's Dictionary. 



285 



ave so changed by means of certain 

 instruments, and principally fire, that 

 their several powers and virtues are 

 thereby discovered with a view to 

 philosophy or medicine. 



Boerhaave, 



Cobalt, a marcasite, frequent in 

 Saxony. 



Fermentation, a glow motion of 

 the intestine particles of amixtbody 

 arising usually from the operation of 

 some active acid matter, which rare- 

 fies, exalts, and subtilizes the soft 

 and sulphureous particles ; as when 

 leaven or yest rarefies, lightens, and 

 ferments bread or wort. And this 

 motion differs much from that usu- 

 ally called ebullition or efferves- 

 cence, which is a violent boiling and 

 struggling between an acid and an 

 alcali when mixt together. 



Galvanism ; the action of met«d- 

 lic substances. 



Glass. An artificial substance, 

 made by infusing fixed salts and 

 flint, or sand, together, with a vehe- 

 ment fire. 



Gold is the heaviest, the most 

 dense, the most simple, the most 

 ductile, and most fixed of all bodies: 

 not to be injured either by air or 

 fire, and seeming incorruptible. It 



subordinate laws, and of improving 

 the useful arts. Black. 



Most of the substances belonging 

 to our globe are constantly under- 

 going alterations in sensible quali- 

 ties, and one variety of matter be- 

 comes, as it were, transmuted into 

 another. The object of chemical 

 philosophy is to ascertain the causes 

 of all such phenomena, whether na- 

 tural or artificialj'^and to discover 

 the laws'! by > which they are go- 

 verned. Dai?y. 



Cobalt, a brittle metal ; much 

 used in the state of oxide, to give a 

 blue colour to glass and porcelain. 



Fermentation is a term employed 

 to signify the spontaneous changeg 

 which certain vegetable solutions 

 undergo, placed under certain cir- 

 cumstances, and which terminate 

 either in the production of an intoxi- 

 cating liquor or of vinegar : tlie 

 former termination constitutes linoiw, 

 the latter, acetous fermentation. 



Galvanism, the electricity ex- 

 cited by the contact of certain dis- 

 similar metallic substances. 



Glass is any substance or mix- 

 ture, earthy, saline, or metallic, 

 brought by igneous fusion to the 

 state ofa hard, brittle, uniform mass, 

 breaking with a conchoidal fracture 

 passing into splintery, and with a 

 high degree of lustra. Transpa- 

 rency is also a character of most 

 glasses. 



Gold, a metal of a pure yellow 

 colour, of a specific gravity exceed- 

 ing that of all known substances, 

 except platinum ; very ductile and 

 malleable ; fusible at a bright red 



