276 INDEX. 



Fig, common, juices of fruit of, changed into sugar, i. 426 



poison of the white juice of the, i. 426 

 Filarise, structure and mode of reproduction of, ii. 147 

 Filices, or ferns, structure and habitat of, i. 335 



range of non-arborescent ferns, i. 335 



number of species in North America, Britain, and in other places, 

 i. 336 



development of spores, i. 336, 337 



roots and stems of, i. 339 



leaf-stalks of, i. 340 



fronds of, i. 340, 341 



structure of tree-ferns, i. 341 



fructification of, i. 341 

 sori, i. 341, 342 

 sporangia, i. 342, 343 



foundation of the systematic arrangement of the ferns, i. 343 



annulate and exannulate ferns, i. 344 

 Film fern, structure and habitat of, i. 362 

 Fire-damp of coal mines, i. 118 



Fireworks, mode of the obtaining of different colours in, i. 132 

 Fish, phosphorence of, i. 67 

 Flowering fern, i. 364 

 Flowers, absorption of radiant heat by the perfumes of, i. 44 



weight of the perfumes, i. 45 



chemical combinations forming the perfumes of, i. 97 



general structure of flowering plants, i. 378 



chemical nature of the colours of, i. 428, 429 

 Fluorescence, property of, in some solids and liquids, i. 60 



Sir D. Brewster's discovery of, i. 66 



Professor Stokes's examination of the fluorescent spectra of metals, 

 i. 64 



employed in tracing substances in impure chemical solutions, i. 67 



rapid absorption accompanied by copious fluorescence, and the 

 converse, i. 67 



essential difference between fluorescence and phosphorence, i. 67, 68 

 Fluorine, i. 18 

 Fluor spar, i. 18 



crystals of, i. 18 



acid obtained from, i. 18 



fluorescence of, i. 60, 66 



absorption of invisible rays by, i. 65 



phosphorescence of, i. 66 

 Flustra, or sea-mat, structure of the, ii. 218 



