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FLU 



in its common state, represents 

 rudely the outline of the body 

 inclosed. But the internal struc* 

 ture retains traces of all its tubes 

 and fibres, most delicately preserved 

 in a reddish caldedony. Sir H. 

 Davy found pure flint in the cuticle 

 of many grasses ; it is also found in 

 the hollow stems of bamboo ; the 

 ashes of wheat straw are also found 

 to contain it. 



FLI'NTY SLATE. Flinty slate differs 

 from common slate, in containing 

 a large portion of siliceous earth. 

 Slate and flinty slate not only pass 

 into each other, but frequently 

 alternate. When flinty slate ceases 

 to have the slaty structure, it 

 becomes hornstone, or, what the 

 French geologists term petrosilex. 

 If it contains crystals of felspar, 

 it becomes hornstone porphyry. 

 JBakewett. 



FLO'ATSTONE. The white and grey 

 porous varieties of rhombohedral 

 quartz. In consequence of their 

 extreme pourousness they swim on 

 the surface of water, and have 

 therefrom been named floatstone, 

 or spongiform quartz. 



FLOETZ. (flotz, Germ.) The name 

 given by Werner to certain rocks 

 which were flat, horizontal, and 

 parallel to each other. Werner 

 employed this term, in lieu of 

 secondary, for the rocks reposing 

 on his transition series, from the 

 belief that they generally were 

 stratified in planes nearly horizon- 

 tal, while those of the older strata 

 were inclined to the horizon in 

 considerable angles. This however, 

 holds good only as regards the 

 structure of countries comparatively 

 low ; in mountain ranges Werner's 

 floetz formations are highly incli- 

 ned. As therefore vertical floetz 

 formations imply a manifest con- 

 tradiction of terms, the use of the 

 word floetz in the place of secon- 

 dary is inadmissable. 



FLO'BA. (Lat.) As the animals 



peculiar to any country constitute 

 its fauna, so do the trees and plants 

 itsj#ora; the botany of a country. 



FLO'EAL. (floralis, Lat.) An epi- 

 thet for a bud or leaf; pertaining 

 to flowers; belonging to the 

 flower. The calyx is the outer set 

 of i\iQ floral envelopes. 



FLO'BET. (fleurette, petite fleur, Fr.) 

 A floret is a small monopetalous 

 flower, many of which, enclosed in 

 one calyx or perianthium, and 

 placed sessile on a common un- 

 divided receptacle, form a species 

 of compound flower. 



FLU' ATE. A compound of fluoric acid 

 with a salifiable base. 



FLTJ'CAN. A provincial name for a 

 fault or dam ; particularly used by 

 the Cornish miners. 2. A term 

 applied by the Cornish miners to 

 either a white or a greenish clay, 

 without regard to its composition. 



FLTJ'OE. ] (Lat.) Octahedral 



FLTJ'OE SPAE. ) fluor. Octaedris- 

 cbes Flus-Haloide of Mohs. Chaux 

 Fluate of Haiiy. Fluate of lime ; 

 consisting of 67*75 lime and 32-25 

 fluoric acid. If a cube of fluor 

 spar be split with a knife and a 

 hammer, it will yield only in the 

 direction of the solid angles, and 

 if the division be pursued the 

 result will be an octohedron. There 

 are three varieties of fluor spar; 

 the first, with even fracture and 

 feeble lustre, is called compact 

 fluor; the second, in which the 

 cleavage is distinct, foliated fluor ; 

 the third, which occurs incrusting 

 other minerals, earthy fluor. See 

 also Blue-John and Derbyshire spar. 



FLUOE'IC ACID, i An acid first pro- 



FLUO'EINE. ] cured by Gay 

 Lussac, or by Margraff, and called 

 fluorine by Sir H. Davy. It may 

 be obtained by putting a quantity 

 of fluor-spar in powder into a 

 leaden retort, pouring over it an 

 equal quantity of sulphuric acid, 

 and then applying a very gentle 

 heat. From its exceedingly de- 



