INDEX. 269 
Emery, description, properties, and uses of, 33 
., how prepared for use, 33 
, red, 43 
Epsom salts, description of, how made, and uses of, 126 
F. 
Faults, in mining, what they are, 3 
Felspar, common, description and uses of, 69 
, Labrador, 69 
Figure stone, description and uses of, 84 
Filtering stone, of what made, 233 
Fire damp in coal-mines, what it is, how produced, &c. 19, 153 
Flint, description and uses of, 53, 54 
, gun-flints, how made, 54 
Florence marble, description and use of, 115 
Fluat of lime, 119 
Fluats, 13 
Fluoric acid, what it is, 13 
. , how to etch on glass by means of, 120 
', mode of obtaining, 120 
Fluor spar, description and properties of, 119 
, how manufactured, and the uses of, 119 
Flux, white, of what made, 137 
, black, 137 
Freestone, description and uses of, 233 
French chalk, description and uses of, 92 
Fuller's earth, description and use of, 87 
Fulminating powder, 176 
silver, extraordinary properties of, 182 
Fumigating of rooms, how effected, 133 
Fur in tea kettles, how formed there, 114 
G. 
Galena, what it is, 203 
Gangue, in mining, what it is, 4 
Garnet, precious, where found, how cut, and value of, 42, 43 
, how set, and uses of, 42 
, common, 43 
, Syrian and pyrope, 43 
Gas, what it is, 10 
Gas lights, history and uses of, 156 
i, how produced, 156 
, how exhibited on a small scale, 156 
Gems, engraving, cutting, and value of, 21 23 
, imitations of, 22 
Giant's causeway, account of, 95 
Gilding on iron or copper, how performed, 172 
- in or-moulu, what it is, 172 
- on silver, how performed, 172 
