Formic acid, synthetical formation of, i. 424
Frond, or thallus, of lichens, i. 301 of ferns, i. 340, 341
Fruit, chemical combinations forming the perfumes of, i. 97 preserved, greenish and grey moulds on, i. 285 fungus on decayed, i. 290
Fucaceæ, structure and fructification of, i. 244, 250, 251
Fucus platycarpus, male and female cells of, i. 253, 254
Fucus vesiculosus, or bladder-wrack, structure and fructification of, i. 252, 253 form of, in the Mediterranean, i. 258
Funaria hygrometrica, structure of, i. 324, 327
Fungi, enormous numbers of, i. 260 structure of, i. 260 two principal groups of, i. 260 families of, i. 261, _et seq._ poisonous matter in all, i. 264 luminous, i. 264 stems of, i. 268 spawn of the gelatinous or creamy fungi, i. 269 universality of the lower fungi, i. 273 destruction caused by them, i. 273 parasitic fungi, i. 274 conidium, or spore-dust cell, i. 279 propagation of fungi by fragments of spawn, i. 281 extreme minuteness and profusion of fungi, i. 297 sudden and often disastrous appearance of the lower fungi, i. 297 conditions necessary to the development of fungi, i. 297
Furcellaria fastigiata, mode of reproduction of, i. 229 structure and mode of reproduction of, i. 235, 238
Fusarium tremelloides, its identity with the nettle Peziza, i. 292
Galeolaria lutea, structure, development, and mode of reproduction of, ii. 107, 108
Gases, absorption and radiation of radiant heat by gases and vapours, i. 38 relation between the density of the gas and the quantity of heat extinguished or absorbed, i. 40 experiments on coloured gases, i. 40 table showing the absorption of various gases at a common pressure, or tension of one atmosphere, i. 41 table of absorption for one inch of tension, i. 4 causes of the difference between the absorptive power of compound and simple gases and vapours, i. 42 radiation equal to absorption, i. 46 action of different thicknesses of the same gas or vapour on radiant heat, i. 47 dynamic absorption and radiation, i. 49 great opacity of a gas to radiations from the same gas, i. 52 the specific heat of compound gases generally greater than that of their component elements, i. 101 law of equivalency in weight of, i. 102 diffusion of, i. 111 Prof. Graham’s experiments, i. 112 effusion of, 109, 110, 113 Prof. Graham’s experiments, i. 113 atmolysis, or method of analysing gases, i. 111, 112, 114 internal movement of molecules of matter in a gaseous state, i. 113 coal gas, i. 117 spectrum analysis of, i. 139 oxygen, i. 139 hydrogen, i. 139 nitrogen, i. 140 chlorine, i. 140 bromine, i. 140 iodine, i. 140 superposed spectra of rarefied compound gases, i. 141 researches of M.M. Bunsen and Kirchhoff, i. 141 spectra of the rarefied vapours of:— sodium, i. 141 iron, i. 142 calcium, i. 142 strontium, i. 142 lithium, i. 142 barium, i. 142 magnesium, i. 142 effect of high temperature on various spectra, i. 142, 143 effects of pressure on various spectra, i. 145