i. 124

Rock-crystal, formation of, i. 17

Rock-salt, chlorine obtained from, i. 18 permeable to radiant heat but radiates badly, i. 37

Roots, downward tendency of, i. 382 structure and functions of, i. 409

Rosalina ornata, structure of, ii. 41

Rosaniline, or roseine, the base of aniline, i. 123 production of, i. 123

Rosaniline, chemical composition of, i. 128

Rosemary, amount of radiant heat absorbed by the perfume of, i. 44

Roses, otto of, amount of radiant heat absorbed by the perfume of, i. 44

Rotalia, structure of, ii. 38

Rotalia Beccarii, habitat and structure of, ii. 42

Rotaline group of foraminifera, ii. 44

Rotifer, common, structure of the, ii. 167

Rotifera, characters of the, ii. 162 mode of reproduction of the, ii. 162

Rubia tinctorum, madder obtained from the roots of, i. 124

Rubidium, i. 3, 4 atomic weight of, compared with that of hydrogen, i. 100 one of an isomeric triad with cæsium and potassium, i. 105 M. Bunsen’s discovery of the metal by spectrum analysis, i. 134, 135 mode of distinguishing it from potassium, i. 135 properties of, i. 136 where found, i. 136

Ruby, i. 4

Ruhmkorff’s electro-magnetic induction apparatus, i. 32

Russulæ, laticiferous vessels of, i. 263

Rust of wheat, i. 281

Rye, probable cause of the mildew of, i. 297

Rytiphlæa pinastroides, antheridia of, i. 243

Rytiphlæa tinctoria, antheridia of, i. 242

S

Saffron, meadow, poisonous alkaloid obtained from, i. 427

Sagartia miniata, structure and habitat of, ii. 132 its deadly weapons, ii. 132, 133

Salpa maxima, structure of, ii. 226, 227

Salpa mucronata, vast shoals of, ii. 228

Salpa zonaria, young of, ii. 227

Salpi, their food, i. 205

Salpidæ, characters of the, ii. 226-228

Salt, change of volume of, by chemical combination, i. 20 partial decomposition of, by diffusion, i. 111 yellow coloured light produced by the combustion of, i. 132 spectrum analysis of, i. 134

Salt: more universally diffused than any other matter, i. 134 spectrum analysis of the rarefied vapour of, i. 141

Sand of the sea-shore, the debris of quartz rocks, i. 17

Sandal wood, amount of radiant heat absorbed by the perfume of, i. 44

Sandhopper, structure of the, ii. 201, 202

Sap milk, composition and formation of, i. 425

Sapindaceæ, or soapworts, fruits of, innocuous, i. 426

Sapphire, i. 4

Sapphirina fulgens, structure and habitat of, ii. 204, 205

Sarcode, structure and functions of, ii. 2

Sarcophycus of the Antarctic Ocean, i. 256

Sarcophycus potatorum, fruit of, i. 256

Sargassum, habitat of the, i. 255

Sargassum bacciferum, structure, fructification, and habitat of, i. 257

Sargassum vulgare, structure, fruit, and habitat of, i. 257

Saturn, the planet, spectrum of, i. 158, 161

Sausages, fatal effects caused by, i. 285

Saw-dust, manufacture of into oxalic acid, i. 116, 117

Scalariæ, tongues of, ii. 239

Scallop, or pecten, eyes of the, ii. 235

Schistocarpi, characters of the group, i. 328

Schistostegei, structure and habitat of, i. 331

Schizæa, structure of, i. 363

Schizæineæ, characters of the, i. 363 sporangia of, i. 343 characters of the group, i. 345

Sclerogen, i. 175 production of, in plants, i. 421

Scolopendrieæ, characters of, i. 351, 352

Scolopendrium, structure and development of the caudex of, i. 340

Scolopendrium vulgare, or Hart’s-tongue fern, structure, fructification, and habitat of, i. 351, 352

Screw pine, roots and habitat of, i. 387

Scutella, spines of the, ii. 180

Scutula, organs of reproduction of, i. 307

Sea-cucumbers, structure and mode of reproduction of, ii. 183

Sea-eggs, or sea-urchins, structure of, ii. 176 _et seq._

Sea-fans, structure of the, ii. 125

Sea-mat, structure of, ii. 218

Sea-nettles, vast shoals of, ii. 100, 101

Sea-pens, structure of, ii. 128, 129-131

Sea-salt, chlorine obtained from, i. 18

Sea-serpent of Celebes, ii. 186

Sea-slugs, structure of, ii. 239, 240

Sea-weeds, former and present uses of, i. 128

Seeds of two lobes, i. 177 of one lobe, i. 177 of plants, i. 381, 382, 383, 404

Selaginella, structure and habitat of, i. 374

Selenium, atomic weight of, i. 105 its properties analogous with those of sulphur and tellurium, i. 105

Sepedonium mycophilum, spores of, i. 286

Sepia, or cuttle fish, structure of, ii. 245, 246, 247

Serpentine marble of Tyree and of Connemara, composition of, ii. 56

Serpula, structure of, ii. 155

Sertularia cupressina, structure of, ii. 87

Sertulariidæ, characters of the family of, ii. 90, 91 modes of propagation of, ii. 91

Shells of mollusks, ii. 234

Shrimps, opossum, ii. 199, 200

Sigillaria, structure of the fossil, i. 375

Silex, quantity of, in the Equisetaceæ, i. 369 in the grasses, i. 386

Silica, abundance of, i. 17 in the stalks and leaves of the grasses, i. 386 effect of electricity on, i. 32

Silicon, i. 17 combined with oxygen gas forms rock-crystal, i. 17 three different states in which it exists, i. 18 analogy between silicon and carbon, i. 18 Professor Graham’s limpid solution of, i. 18

Silk, dyes for, i. 125 mode of preparing it if it is to be moiré, i. 125 advantages of the climate of Lyons in the manufacture of, i. 126

Silk-worm, a fungus parasite of the, i. 274

Silver, affinity of, for oxygen, i. 5 conduction of heat and radiation, i. 5 iodine found in combination with, i. 19 crystals of, formed artificially by electricity, i. 74 transmissive power of, of electricity, i. 90

Sipunculidæ, structure and mode of reproduction of, ii. 186, 187

Sky, probable cause of the blue colour of the, i. 58

Slate, polishing, of Bilin, of what it consists, i. 206

Smoke, i. 14

Smut of wheat, i. 281

Snails, structure of, ii. 235-237

Soda, chlorate of, singular property of, in crystallization, i. 75

Soda, oxalate of, formation of, i. 117

Soda, silicate of, i. 110 Prof. Graham’s dialysis of, i. 110

Soda, former and present mode of procuring, i. 128 yellow coloured light produced by the combustion of, i. 132 abundance in the Algæ, i. 414

Sodium, i. 3 atomic weight of, compared with that of hydrogen, i. 100 spectrum analysis of the rarefied vapour of, i. 141 chloride of, spectrum of, i. 146 reversion of the coloured lines of sodium burning in air, i. 150

Solar spectrum, i. 58 myriads of ethereal waves constituting the seven colours of the, i. 58 rayless spaces crossing the, at right angles, i. 59 length of the undulations of the ether producing the impression of the colours of the solar spectrum, i. 59 mode of bringing the invisible rays of the chemical spectrum before the human eye, i. 59 fluorescence and calorescence, i. 60-62 experiments producing the long spectrum, i. 63 spectra of volatilized metals, i. 64 absorption of invisible rays, i. 65 discoveries of Sir Isaac Newton of the solar spectrum and the laws of coloured rings, i. 129 Fraunhofer’s lines, i. 129, 148 MM. Bunsen and Kirchhoff’s experiments, i. 130, 148 Mr. Glaisher’s experiments, i. 130 absorption bands, i. 131 Sir D. Brewster’s discovery, i. 131 coincident dark and coloured lines, i. 148 reversion of the coloured lines, i. 149 Prof. J. P. Cook’s discoveries, i. 149 M. Foucault’s discoveries, i. 149 M. Kirchhoff’s discovery of the law of exchanges, i. 150 metals shown by MM. Kirchhoff and Angström to exist in the sun, i. 151-153 and those proved to have no existence in the sun, i. 154

Solferino, production of, i. 127

Solids, the specific heat of compound, generally greater than that of their component elements, i. 101

Solorina, structure of the genus, i. 305

Solorina crocea, structure of, i. 306

Solorina saccata, structure of, i. 305

Space, matter wandering in, i. 28

Spearmint, absorption of radiant heat by the perfume of, i. 44

Specific gravity, i. 26 unit of, i. 26

Spectra, continuous, from glowing solids and liquids, i. 132 spectrum analysis, i. 133 experiments of Sir David Brewster and Mr. Fox Talbot, i. 133 spectrum of rubidium and cæsium, i. 136 of thallium, i. 136, 137 of indium, i. 137 of the flame of the iron in the manufacture of the Bessemer steel, i. 137, 138 of gases, i. 139, _et seq._ effect of high temperature on various spectra, i. 142-144 effects of pressure on a variety of gases and vapours, i. 145 of metals not always the same, i. 145 of the halogens, i. 146 of the vaporized mixture of five chlorides, i. 147 of lightning, 147 of the sun. _See_ Solar spectrum of the fixed stars, i. 155, 162, 163 of temporary and periodic stars, i. 156, 157 of the planets, i. 157, 158, 161 of various nebulæ, i. 158-160

Spermatozoids of confervaceæ, i. 210

Sphæria aquila, structure and habitat of, i. 295

Sphæria bombarda, structure of, i. 295

Sphæria, candle-snuff, habitat of, i. 295

Sphæria Desmazierii, development of, i. 294

Sphæria miliaris, characters of, i. 283

Sphæriacei, characters and habitat of the order, i. 293 development of, i. 294

Sphærobolus, force with which its sporangium is ejected, i. 273

Sphærococcoideæ, characters of the, i. 238

Sphærococcus coronopifolius, mode of reproduction of, i. 236, 238

Sphærococcus, habitat of the genus, i. 239

Sphærophorei, characters of the, i. 310

Sphæroplea annulina, structure and reproduction of, i. 208, 209

Sphagnei, characters of, i. 331

Sphagnum latifolium, leaves of, i. 330

Sphagnum, or common bog-moss, structure, fructification, and habitat of, i. 332 uses of, in Lapland, i. 334

Spikenard, amount of radiant heat absorbed by the perfume of, i. 44

Spinal cord, structure and functions of the, ii. 8

Spines of plants, structure and formation of, i. 411

Spirogyra, mode of reproduction of, i. 218

Spirulina tenuissima, motions of, i. 213

Splachnei, characters of the tribe, i. 330

Splachnum ampullaceum, structure and habitat of, i. 331

Splachnum vasculosum, structure and colour of, i. 330

Spondylus gædaropus, eyes of the, ii. 235

Sponges, iodine found in, i. 19

Sponges, the Carpenteria, a link between the foraminifera and the, ii. 57 structure and development of, ii. 57 varieties in size, structure, and habits of the marine sponges, ii. 60 propagation of, ii. 60, 61 structure of fresh-water sponges, ii. 61 fossil sponges, ii. 62

Spongilla fluviatilis, structure and development, and propagation of, ii. 61

Spongiocarpeæ, structure and mode of propagation of, i. 237, 238

Spores of Cryptogamia, i. 177, 178

Sporidia, or spore-bearing cells, of Ascomycetes, i. 290

Sporidiiferi, structure and fructification of, i. 260 orders of, i. 260, 261

Sporiferi, structure and fructification of, i. 260 orders of, i. 260

Sporopodium Leprieurii, ascus of, i. 300

Spurgeworts, poisons and food supplied by the, i. 425, 426

Squamariæ, structure and modes of propagation of, i. 237

Squid, structure of the, ii. 245, 246

Squilla Desmarestii, structure of, ii. 198

Squilla mantis, structure of, ii. 198

Stamens of flowering plants, i. 379

Starch, production of, by plants, i. 420

Star-fishes, structure of, ii. 169

Stars, absorption of the heat radiated by the, by the earth’s atmosphere, i. 55 chemical power of the light of the, i. 55

Stars, falling, i. 28

Stars, fixed, constitution and spectra of the, i. 154, 155, 162, 163 spectra of periodic stars, i. 156

Staurastrum, structure and development of various species of, i. 192

Steam-engine, equivalence between the mechanical work and heat of the, as between cause and effect, i. 29 causes of the motive force in the, i. 29

Steel, effect of magnetism on, i. 77 importance of the spectrum analysis in the manufacture of, by Bessemer’s process, i. 137, 138

Stegobolus Berkeleianus, structure and organs of development of, i. 299

Stelleridæ, structure and mode of reproduction of, ii. 169-172, 174

Stems of plants, structure of, i. 384, 405

Stenochlæna, stem of, i. 339

Stephanosphæra pluvialis, structure and development of, i. 187-189

Stickleback, entozoön of the, ii. 145

Sticta, structure of the genus, i. 304

Sticta pulmonacea, structure and habitat of, i. 304

Stilbacei, structure and habitat of, i. 283

Stomach, human, fungus in the, i. 275

Stomapoda, characters of the, ii. 198

Stomata of plants, structure of the, i. 405, 406

Stone-lilies, structure of, ii. 174, 175

Strawberry, fructification of the, i. 381

Strombus gigas, or queen conch, shell of, ii. 234

Strontium, i. 3 one of an isomeric triad with calcium and barium, i. 105 red-coloured light obtained by the combustion of, i. 133 spectrum analysis of, i. 133 spectrum analysis of the rarefied vapour of, i. 142 effect of high temperature, i. 142, 143

Strychnos nux vomica, fruit of, food for birds, i. 426

Substitution, direct or indirect, the basis of the modern doctrine of equivalents, i. 104

Succinic acid, chemical combination forming, i. 97

Sugar, production of, in plants, i. 421

Sugar-cane, size and structure of, i. 386

Sulphur, i. 16 extensive range of affinities of, i. 16

Sulphur: dimorphism and allotropism of, i. 16 combination of chlorine with sulphur, i. 20 atomic weight of, compared with that of hydrogen, i. 100, 105 its analogous properties with selenium and tellurium, i. 105 spectrum analysis of, in different temperatures, i. 144

Sulphuretted hydrogen gas, i. 16

Sulphurous acid, amount of absorption of radiant heat by, i. 41

Sun, probable cause of the light and heat of the, i. 28 probability of the periodic connection of the solar spots with magnetic phenomena, i. 30, 31 amount of force exerted by the sun’s light within the limits of the terrestrial atmosphere, i. 34 chemical action of the light of the sun, i. 56 effect of the opalescence of the atmosphere on the chemical power of the sun’s light, i. 57

Sun, spectrum of the, i. 58 thirteen terrestrial substances in the sun’s atmosphere, i. 59 metals shown by M. Kirchhoff to exist in the sun, i. 151-153 and those proved not to exist in it, i. 154 the structure of the sun in some respects still a mystery, i. 164 the luminous gaseous atmosphere of the, i. 164 mottled appearance of the photosphere of the sun, i. 164, 165 the faculæ, i. 165 the red flames or protuberances round the edge during a total eclipse, i. 165 the solar spots, i. 166 their periodicity, i. 166 appear to be influenced by the planet Venus, i. 166

Sun-rise and sun-set, causes of the bright tints at, i. 58

Surirella, mode of development of, i. 202

Synapta, structure of the genus, ii. 185

Synapta digitata, structure and habitat of the, ii. 185

Syncladei, structure of the branches of, i. 328

Syncoryna Sarsii, structure and development of zooids of, ii. 90

Synthesis, in the animal and vegetable creation, i. 96

T

Tænia, or tape-worm, structure and mode of reproduction of, ii. 145 transformation of the young of, ii. 146.

Tænioïdæ, characters of, ii. 144

Talitrus, or sand-hopper, structure of, ii. 201, 202

Tar, coal. _See_ Coal tar

Tardigrada, characters of the, ii. 161

Tartaric acid, chemical combination forming, i. 97

Tea, active principle of, i. 428

Tellurium, atomic weight of, i. 105 its properties analogous to those of sulphur and selenium, i. 105

Terebella conchilega, structure of, ii. 153-155

Textularia, structure and habitat of the genus, ii. 41 fossils of, ii. 42

Textularia Mayeriana, form of, ii. 28

Thalassicolla morum, structure of, ii. 21

Thalassicollæ, structure of, ii. 21

Thalassiophyllum Clathrus, habitat and structure of, i. 250

Thallium, i. 3, 4 effect of the spectrum from an electric spark between points of, i. 64 atomic weight of, compared with that of hydrogen, i. 100 Mr. W. Crookes’s discovery of the metal so called, i. 136 spectrum analysis of, i. 137 properties of, i. 137 where found, i. 137 changes in the spectrum of, by high temperature, i. 144

Thallus or frond, of lichens, i. 301

Thaumantia pilosella, form and structure of, ii. 92 otolites of, ii. 93 mode of reproduction of, ii. 94

Thorinum, i. 4

Thunder-dirt of the New Zealanders, i. 268

Thyme, absorption of radiant heat by the perfume of, i. 44

Timmia, leaves of, i. 330

Tobacco, spectrum analysis of, i. 136

Tobacco, narcotic effect of, and as a relief from hunger, i. 428

Toluidine, property of, in producing the aniline colours, i. 122

Toluol, constituents of, i. 121

Topaz, oriental, i. 4

Torula cerevisiæ, structure, development, and cell-multiplication of,