Ceterach officinarum, or scaly spleen-wort, structure, organs of fructification, and habitat of, i. 354, 355 Cetraria, or Iceland moss, characters of the genus, i. 304 Cetraria tristis, structure of, i. 304 Ceylon, the black mildew of, i. 297 Chamomile flowers, amount of radiant heat absorbed by the perfume of, i. 44 Chantarelle, veins of the, i. 264 Characeæ, structure and habitat of, i. 312 fluid currents of, i. 312, 313 reproductive organs of, i. 313 Chara fragilis, structure and mode of reproduction of, i. 314, 315 Charcoal, i. 13 as a conductor of electricity, i. 32 Cheese, blue and brick-red moulds on, i. 285 Cheilanthes odora, scent of, i. 347 Chelidonine, whence obtained, i. 427 Chemistry, laws placing it on a strictly numerical basis, i. 93 Chimneys of bad construction, i. 14 Chiodecton monostichum, structure and habitat of, i. 309 Chiodecton myrticola, habitat of, i. 309 Chirodota, structure and habitat of, ii. 186 Chirodota lævis, wheels of the, ii. 186 Chirodota myriotrochus, wheels of the, ii. 186 Chloride of lime, i. 19 Chlorides, spectra of the, i. 146, 147 Chlorine, i. 18 whence obtained, i. 18, 19 properties of, i. 19, 22 affinity for hydrogen, i. 19, 20 substances produced by the combination of chlorine with oxygen, i. 20 and with nitrogen, and with sulphur, i. 20 Professor Schönbein’s views as to, i. 20, 21 spectrum of, i. 21 absorption of radiant heat by, i. 41, 42 its affinity for iodine, i. 96 atomic weight of, compared with that of hydrogen, i. 100 spectrum analysis of, i. 140 Chlorine gas, substances which take fire spontaneously in, i. 19 combustion of, i. 19 Chlorospermeæ, characters of, i. 180 structure and development of, i. 181 Chondrus crispus, or Carrigeen, structure and mode of propagation of, i. 235, 236 effect of fresh water on the form of, i. 243 Chorda filum, structure and habitat of, i. 245 Chordaria divaricata, spore cysts of, i. 246 Chordariæ, structure of, i. 245 Chrysophonic acid, whence obtained, i. 303 Chylocladia kaliformis, structure and mode of propagation of, i. 235 Cibotium Barometz, caudex of, i. 350 Cidaris, spines of the, ii. 180 Cinchoneæ, alkaloids obtained from, i. 427 Cinchonine, structure of, and whence obtained, i. 427 Cirripedia, characters of the, ii. 213 Cladocarpi, characters of the group, i. 328 Cladocera, characters of the order, ii. 208 Cladonia, structure of, i. 306 Cladophora, structure of the genus, i. 222 Cladophora pellucida, structure of, i. 222 Claudea, structure of, i. 242 Clavariei, structure and habitat of, i. 266 Clio pyramidata, structure of, ii. 242, 243 Cliona, structure and burrowing apparatus of, ii. 60 Clione borealis, structure and habitat of, ii. 243 fossil remains of, ii. 244 Closterium, double circulation of the internal fluid in, i. 193 Closterium lunula, structure and development of, i. 193