Part 3 — INDEX.

A

Abrothallus, organs of reproduction of, i. 307

Absorption of light and heat, i. 34 effects of, i. 35, 36 generally independent of colour, i. 36 Melloni’s investigations into the laws of, i. 38 Prof. Tyndall’s experiments, i. 38 amount of radiant heat absorbed by the perfumes of flowers and plants, i. 43-45 experiments showing radiation to be equal to absorption, i. 46 great absorption of olefiant gas, i. 47 absorptive power of aqueous vapour, i. 53 dynamic absorption, i. 49 absorption a phenomenon irrespective of aggregation, i. 53 absorption of invisible rays by solids, liquids, and gases, i. 65

Absorption bands in the red and green parts of the solar spectrum, i. 131

Acalepha, the simple hydra a phase in the life of the, ii. 91

Acalephæ, Campanograde, characters of, ii. 103

Acalephæ, Ciliograde, characters of the, ii. 101 mode of reproduction of, ii. 103

Acalephæ, Physograde, characters of, ii. 107

Acanthometræ, structure and habitat of, ii. 19

Acetic acid, chemical combination forming, i. 97

Acetic fermentation, fungus producing, i. 288

Acetylene, formation of, i. 97

254Acetylene, chemical composition of, i. 128

Achlya prolifera, structure and reproduction of, i. 220

Acids, their affinity for alkalies, i. 96

Acineta, structure and mode of reproduction of, ii. 77, 78 food of, and mode of seizing it, ii. 78

Acorn-shell, structure of the, ii. 213

Acrocarpi, characters of the group, i. 328

Acrocladia mamillata, spines of the, ii. 180, 181

Acrosticheæ, characters of the, i. 359, 360

Actinia sulcata, structure of, ii. 132

Actinian polype, structure and mode of reproduction of, ii. 130, 131

Actinian zoophytes, characters of, ii. 130, 131 thread-cells, ii. 132 structure of, ii. 134-136

Actinism of star-light, i. 55 of moon-light, i. 55 of sun-light, i. 56

Actinocyclus undulatus, structure of, i. 199, 200

Actinomma drymodes, structure of, ii. 21

Actinophrys sol, structure and reproduction of, ii. 16-18 certain degree of instinct exhibited by, ii. 18 its enemy, the Amœba, ii. 18

Adder’s tongue fern, i. 365

Adiantieæ, characters of the groups, i. 358

Adiantum Capillus-Veneris, or maiden’s-hair fern, structure and habitat of, i. 359

Adriatic sea, Foraminifera in the ooze of the bed of the, ii. 51

Adularia, or moonstone, fluorescent property of, i. 66

Æcidium, characters of, i. 280

Ægean sea, zones of Algæ in the, i. 259

Æthalium septicum, structure and habitat of, i. 270-272 Amœba-like motions of, i. 270 mode of reproduction of, i. 271

Affinity, chemical, of kind and of degree, i. 95 relation between chemical affinity and mechanical force, i. 98

Agaricini, the order, i. 261

Agaricus, the genus, i. 261, 263 structure of the, i. 263

Agaricus arvensis, spawn of, i. 262

Agaricus campestris, or common mushroom, i. 261 structure and mode of reproduction of, i. 261

Agaricus gardneri, luminosity of, i. 264

255Agaricus olearius, luminosity of, i. 264

Air, a non-conductor of electricity, i. 32 amount of force exerted by the sun’s light within the limits of the terrestrial atmosphere, i. 34 absorption of radiant heat by, i. 41 effect of the rays of the sun falling on the earth through pure dry air, i. 53 spectrum analysis of the component parts of the atmosphere, i. 139

Air-vessel of Nereocystis Lutkeana, i. 249, 250

Alaria esculenta, fruit of, i. 249

Alaria Pylaii, fruit of, i. 249

Albumen, formation and structure of, in vegetable organisms, i. 423

Alcohol, chemical combination forming, i. 97

Alcyon zoophytes, characters of, ii. 119, 120 structure and mode of reproduction of, ii. 120-123

Alcyonidium elegans, structure of, ii. 120

Alcyonium digitatum, or dead man’s fingers, structure of, ii. 121, 122

Aldebaran, spectrum of, i. 155

Algæ, i. 179 classification of the group, i. 179-181 green Algæ, i. 181-220 zones or degrees of depth at which different Algæ exist, ii. 221, 258, 259 brackish water often a cause of change in the form of Algæ, i. 245 colossal Algæ of the North Pacific, i. 245 rings of growth of some of the larger sea-weeds, i. 252

Alizarine blue, from what obtained, i. 124, 125

Alkalies, their affinity for acids, i. 96

Alkaloids, chemical structure of, i. 427

Allosorus crispus, or parsley fern, structure and habitat of, i. 358

Allotropism, i. 8 of carbon, i. 15

Alsophileæ, structure of, i. 360

Alum, a free radiator but a bad conductor of radiant heat, i. 37 partial decomposition of, by diffusion, i. 109 manufacture of, i. 120

Alumina, effect of electricity on, i. 32

Aluminum, i. 4 spectrum of, i. 65

Amalgams of metals, illustrating the relation between chemical affinity and mechanical force, i. 98

Amansia, structure of, i. 242

256Amaryllidaceæ, structure and mode of reproduction of, i. 388

America, North, enormous quantities of petroleum in, i. 126

Amidogen combines with other substances and simple atoms as if it were a simple element, i. 106

Ammonia, amount of absorption of radiant heat by, i. 41 characteristics and constituents of, i. 119 chemical composition of, i. 128 combination forming, i. 107 carbonate of, i. 119 extent of the manufacture of, i. 120 muriate of, i. 120 manufacture of, i. 120 sulphate of, i. 120 how manufactured, i. 120

Ammonium, sulphide of, i. 119

Amœba princeps, structure, motions, food, and reproduction of, ii. 13-16 its capture of the Actinophrys, ii. 18 a new species found in dust from Egypt, ii. 65

Amorphous substances, conduct of, under magnetic influence, i. 76

Amphicora, two eye-specks in the tail of, ii. 158

Amphidetus, spines of the, ii. 180

Amphipoda, characters of the, ii. 201

Amphithoæ, structure of, ii. 203

Analysis, chemical, electricity and light instruments of, i. 95 the most powerful means of, i. 96

Andræa subulata, leaves of, i. 330

Andræaceæ, characters of the tribe, i. 328

Angiocarpei, structure, mode of reproduction, and habitat of, i. 309, 310

Angiopteris evecta, perfume from, i. 364, 365

Angræcum sesquipedale, structure and mode of reproduction of, i. 402

Anguillulæ, eel-like entozoa, structure and habitat of, ii. 147, 148

Anemone, sea, structure and mode of reproduction of, ii. 130, 131

Aniline, formation of the fulminate of, i. 92 combination forming, i. 107 how produced, i. 121, 122 constituents and characteristics of, i. 122 formation of the aniline colours, i. 122, 123 mauve, i. 122 magenta, i. 122 purple, i. 123 yellow, i. 124 chemical composition of, i. 128

257Aniline, acetate of, i. 123

Animals, functions of the frame of, ii. 1 sarcode and muscle, ii. 2 blood, ii. 2 waste and repair, ii. 3 food, ii. 3 animal heat, ii. 3 the heart, digestion, heat, and respiration, ii. 4 nerve-force of animals, ii. 4 nervous system, ii. 5 structure and functions of the brain and spinal cord, ii. 8 intelligence, or the mental principle, in animals, ii. 11, 12

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

Annelida, characters of the, ii. 149 mode of reproduction of, ii. 160 luminosity of, ii. 160 fossil remains of, ii. 161

Annulosa, or worms, characters of, ii. 144

Anomura, structure and mode of reproduction of, ii. 197

Antennaria Robinsonii, mode of reproduction of, i. 296

Antennariei, structure of, i. 296

Anthoxanthum odoratum, or sweet-scented vernal grass, mode of reproduction of, i. 386

Anthozoa zoophytes, or living flowers, characters of, ii. 119

Antiaris toxicaria, causes of the virulence of, i. 426 fruit of, innocuous, i. 426

Antozone, i. 8

Aphrodita hystrix, structure and mode of reproduction of, ii. 159

Apolemia contorta, structure and mode of reproduction of, ii. 108, 109

Apple, fructification of the, i. 381

Apus cancriformis, structure of the, ii. 210

Aqueous vapour, i. 53 absorptive power of, i. 53-55

Arachnoidiscus Ehrenbergii, structure of, i. 199

Arcella, structure and mode of formation of the shell of, ii. 21, 22, 23

Aregma speciosum, spores of, i. 276

Arenicola, structure of, ii. 157

Arragonite, i. 108 external and internal alteration of, by heat, i. 108

Artemia salina, structure of, ii. 210

Artocarpus, or bread-fruit tree, i. 426

258Arum, structure and mode of reproduction of, i. 388 water secreted by the, at night, i. 429

Arundo Donax, size of the, i. 386

Ascaris lumbricoïdes, structure and mode of reproduction of, ii. 147

Asci, or sporidia sacs, of Ascomycetes, i. 290

Ascidia virginea, structure, food, and habitat of, ii. 224, 225

Ascidians, or Tunicata, character of, ii. 222 compound or social gelatinous, ii. 222 star-like, ii. 224

Ascomycetes, structure of, i. 290

Ascophora elegans, fructification of, i. 226

Ashes, i. 14

Aspergillus dubius, spores of, i. 286

Aspergillus glaucus, spores of, i. 286

Asphalt, sources of, in various parts of the world, i. 126

Aspidieæ, characters and habitat of the group, i. 346, 348

Asplenieæ, characters and habitat of the group, i. 351, 352, 353

Asplenium lanceolatum, structure, fructification, and habitat of, i. 354

Asplenium marinum, structure and habitat, i. 355, 356

Asplenium Ruta-muraria, or wall rue, structure, habitat, and reproductive organs of, i. 353, 354

Asteroïdea, or star-fishes, characters of the, ii. 169 fossil star-fishes, ii. 174

Athyrium Filix-fœmina, or lady fern, herbaceous caudex of, i. 340 structure and fructification of, i. 352, 353

Atlantic Ocean, profound depths of, north and south, ii. 49 foraminifera at great depths in the, ii. 49, 50

Atmolysis, or method of analysing gases, i. 111

Atmosphere, effect of the heat radiated by the moon on the higher regions of the, i. 55 opalescence of the, and its effect on the chemical power of the sun’s light, i. 55 causes of this opalescence, i. 55 its permeability to every kind of chemical rays, i. 58

Atmosphere of the sun, thirteen terrestrial substances in the, i. 59

Atolls, or coral lagoons, ii. 140

Atoms or molecules of matter, power of atoms of matter on the rays of the solar beam, i. 58 aggregation of matter by electricity, i. 74 effect of the physical forces on molecular arrangement, i. 90, 91 proof of the individuality and polarity of the atoms of matter, i. 91 effect of motion, i. 91

259Atoms: effect of catalysis, i. 91 of matter, i. 2 cohesion of, i. 25 unit of mechanical force, i. 26 the atomic theory, i. 93 the law of definite proportions, in combination and resolution of the component parts of substances, i. 94 affinity of kind and of degree, i. 95 force of chemical combination, i. 97, 98 relative atomic weights, i. 99 table of atomic weights compared with that of hydrogen, i. 100 relation between the atomic weights and the specific gravities of substances, i. 100 capacities of atoms for heat and electricity, i. 100, 101 law of equivalency in weight and volume, i. 102, 103 substitution the basis of this law, i. 104 sequence of atomic numbers, i. 105 groups of substances whose atomic weights are in regular arithmetical series, i. 106 groups of combined atoms called compound radicles, i. 106 the polyatomic theory, i. 107 the force of molecular attraction more powerful than gravitation, i. 109 internal movement of molecules of matter in a gaseous state, i. 113

Aulocantha scolymantha, structure of, ii. 21

Avicula margaritacea, or pearl oyster, nacreous lining of shell of, ii. 234

Azores, the black mildew of the, i. 297

Azote in vegetable organisms, i. 423

Azuline dye, production of, i. 123

B

Babylon, the asphaltic mortar used in building, i. 126

Bacillaria cursoria, motion of, i. 203

Bacillaria paradoxa, motion of, i. 203

Back, Sir George, his arctic journey, i. 308

Bacteria, their structure, size and habitat, ii. 64

Bæomyces, structure of, i. 306

Balanidæ, structure of, ii. 213

Balanus balanoïdes, development of, ii. 216

260Balanus culcatus, structure of, ii. 213-215

Baldness caused by fungi, i. 275

Balms, chemical combination forming the principle of the, i. 97

Bamboo, size and structure of, i. 386

Bangia, characters of the genus, i. 222

Bangia ceramicola, structure and mode of reproduction of, i. 223

Bangia ciliaris, structure and reproduction of, i. 223

Bangia fuscopurpurea, structure and reproduction of, i. 223

Barium, i. 3 one of an isomeric triad with calcium and strontium, i. 105 spectrum analysis of the rarefied vapour of, i. 142 effect of high temperature, i. 143 chloride of, spectrum of, i. 146

Bark of trees, structure of, i. 406, 407

Baryta, green coloured light obtained by the combustion of, i. 133

Batarrea, structure of, i. 267

Batrachospermeæ, habitat and structure of, i. 210

Bean, common, fungus of the, i. 280

Beans, caseine obtained from, i. 125

Beer, yeast of, i. 287

Beetles, fungi in the stomachs of, i. 274

Begonia, structure and mode of reproduction, of, i. 376

Bengal, Bay of, causes of the scarlet colour of the, ii. 72

Benzol, combination forming, i. 118, 127 constituents and characteristics of, i. 121 chemical composition of, i. 128

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

Beroë Forskalia, structure of the, ii. 102, 103

Bhang, whence obtained, i. 427 intoxicating effect of, i. 427

Biddulphia pulchella, structure of, i. 198

Bignonia, fructification of, i. 381, 382

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

Biscay, Bay of, zones of Algæ in the, i. 259

Bisection, propagation of diatoms by, i. 200, 204

Bismuth, diamagnetism of, i. 75, 76 chloride of, spectrum of, i. 146

Bittern, i. 18

Bleaching properties of:— chlorine, i. 19 bromine, i. 20 iodine, i. 21

261Blechnum Spicant, structure, habitat, and mode of reproduction of, i. 356, 357

Blood, formation and functions of, ii. 2, 3

Blue dyes, i. 123, 124

Bog moss, structure, fructification, and habitat of, i. 332

Boleti, habitat and structure of the, i. 265

Boletus æneus, large amount of heat evolved by, i. 265

Bombyx rubi, fungi destructive of, i. 282

Boron, i. 18 whence obtained, i. 18 insolubility of, i. 18 heat at which it burns, i. 18

Botrychium, habitat of the genus, i. 366

Botrychium Lunaria, or moonwort, structure and habitat of, i. 366

Botryllidæ, or star-like Ascidians, ii. 224

Botrytis Bassiana, a fungus parasite of the silk-worm, i. 274

Botrytis curta, development of, i. 294

Botrytis, the cause of the murrain in potatoes, i. 284 structure of, i. 284

Brachionus pala, structure of, ii. 162-166

Brachyura, structure and mode of reproduction of, ii. 189-197

Brackens, i. 358

Brain, structure and functions of the, ii. 8

Branchipes stagnalis, structure of, ii. 210

Bread, fungus which attacks, hot from the oven, i. 296

Bread-fruit tree, food obtained from the, i. 426

Bristle fern, structure and habitat of, i. 361

Bromine, i. 18 whence obtained, i. 18 properties of, i. 20, 22 Professor Schönbein’s views as to, i. 20, 21 spectrum of, i. 21 amount of absorption of radiant heat by, i. 41, 42, 43 atomic weight of, compared with that of hydrogen, i. 100 spectrum analysis of, i. 140

Bryei, characters and structure of the, i. 329

Bryopsis, structure and habitat of, i. 219, 224

Bryozoa, or Polyzoa, characters of, ii. 218

Buckthorn, green dye obtained from, i. 124

Buds of trees, structure and functions of, i. 411

Bugula avicularia, structure of, ii. 220

Bulbous plants, beauty of, i. 387

262Bulbous plants, structure and reproduction of, i. 388

Bunt, germination of the spores of, i. 281

C

Cadmium, i. 4 spectrum of volatilized cadmium, i. 64 chloride of, spectrum of, i. 146

Cæomacei, structure and mode of reproduction of, i. 278

Cæsium, i. 3, 4 atomic weight of, compared with that of hydrogen, i. 100 one of an isomeric triad with rubidium and potassium, i. 105 M. Bunsen’s discovery of the metal by spectrum analysis, i. 134, 135 mode of distinguishing it from potassium, i. 136 its properties, i. 136 changes in its spectrum by high temperature, i. 144

Caffeine, the neutral crystallisable principle of coffee, i. 428

Caladium distillatorium, water secreted by at night, i. 429

Calanus, structure and social habits of the, ii. 206 bloody water formed by the, ii. 206

Calanus pontilla, structure of, ii. 206

Calanus sanguineus, structure of, ii. 206

Calcarina, intermediate skeleton of, ii. 42, 43

Calcium, i. 3, 4 one of an isomeric triad with strontium and barium, i. 105 spectrum analysis of the rarefied vapour of, i. 142 effect of high temperature, i. 143 chloride of, spectrum of, i. 146

Caliciei, characters and habitat of the order, i. 309

Calicium inquinans, spores of, i. 309

Calicium tympanellum, organs of reproduction of, i. 301

Calico-printing, use of oxalic acid in, i. 116

Callithamnion, structure of the genus, i. 231

Callithamnion corymbosum, structure and reproductive organs of, i. 231, 232

Callithamnion sparsum, structure of, i. 231

Calorescence, property of, in some solids and liquids, i. 61

Calyx of flowering plants, i. 378

Cambium of plants, structure of, i. 407, 417

Camptosorus, or walking fern, structure and mode of reproduction of, i. 352

263Campylopus lamellinervis, leaves of, i. 330

Canada, enormous quantities of petroleum in, i. 126

Caoutchouc, whence obtained, i. 426

Carbazotic acid, constituents of, i. 121

Carbohydrates, combinations forming the, i. 116

Carbolic acid, combination forming, i. 107, 120, 121, 128 its property of arresting putrefaction, i. 121 becomes solid when dried and purified, i. 121

Carbon, i. 13 allotropism of, i. 15 at variance with the geometrical system of crystallization, i. 15 analogy between carbon and silicon, i. 18 effect of the combination of the atoms of carbon and oxygen in combustion, i. 30 property of the bisulphide of, in the transmission of heat, i. 36 effect of a discharge of the nitric acid electric battery, with carbon balls on the terminals, i. 84 will not combine directly with hydrogen, i. 97 atomic weight of, compared with that of hydrogen, i. 100 spectra of the compounds of carbon, i. 146 bisulphide of, absorption of radiant heat by, i. 40 opacity of, to the invisible rays, i. 65 in coal gas, i. 118 how freed from coal gas, i. 118

Carbonic acid gas, i. 14 reduced to a solid, i. 15 weight of the atoms of, compared with those of hydrogen, i. 99 absorption of radiant heat by, i. 41 how freed from coal gas, i. 118 one of the illuminants in coal gas, i. 118

Carbonic oxide, absorption of radiant heat by, i. 41 action of different thicknesses of, on radiant heat, i. 48 the poisonous quality of coal gas, i. 118

Carcinus mœnas, structure and reproduction of, ii. 192, 195 moulting and power of reproducing limbs, ii. 197

Cardium, or cockle, structure and mode of reproduction of, ii. 230, 231

Carpenteria, structure and habitat of the, ii. 57 a link between the Foraminifera and the sponges, ii. 57

Carrigeen, or Irish moss, structure and mode of reproduction of, i. 235, 236

Caryophyllia Smithii, its formidable artillery, ii. 133, 134 structure and development of, ii. 134, 135

264Caryophyllia Smithii, locomotion of, ii. 135

Caseine, or cheese, used as a mordant, i. 125 obtained also from pease and beans, i. 125 formation and structure of, in vegetable organisms, i. 423

Cassava, or Manihot, food obtained from the, i. 426

Cassis, or helmet shells, structure of, ii. 234

Catalysis, effect of, on molecular arrangement, i. 91 instances of, i. 91, 92

Catasetum, structure and mode of reproduction of, i. 601

Caterpillars, fungus destructive of, i. 282

Caulerpas, where found, i. 219

Celidium, organs of reproduction of, i. 307

Cellipora, structure of, ii. 218

Cells, vegetable. See Vegetation

Cellulose, produced by plants, i. 419

Cellularia ciliata, structure of, ii. 219, 220

Cephalopoda, naked, characters of, ii. 245

Ceramiaceæ, beauty and habitat of, i. 231 characters of the genus, i. 232

Ceramium ciliatum, structure and organs of reproduction of, i. 232

Ceratopteridineæ, or Parkeriaceæ, characters, structure, and habitat of the group, i. 345, 363

Cerealia, the grasses from whence they were derived unknown, i. 383

Cestum Veneris, structure and mode of reproduction of, ii. 103

Ceterach, characters of the genus, i. 354 structure and mode of reproduction of, i. 354 brought by ocean currents to Europe, i. 355

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

265Cheese, 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

266Cladocera, 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

Cloud, force of the chemical combination requisite to form a, i. 98

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

Club mosses. See Lycopodiaceæ

Coal, i. 13 effect of the consumption of a pound of, in a steam-engine, i. 29, 30 energy in abeyance in the coal existing in the whole globe, i. 30

Coal gas, i. 117, 118 poisonous quality of, i. 118 explosive quality of, i. 118 impurities from which it is freed, i. 118 uses of the black fœtid gas water resulting from the distillation of coals, i. 119

Coal tar, i. 120 substances produced from, by distillation, i. 120 colours, i. 121, 122

Cobalt, i. 4, 5 crystals of, formed artificially by electricity, i. 74 effect of heat in the magnetism of, i. 77

Coccocarpei, characters of, i. 307

Coccocarpia smaragdina, section of, i. 300

Coccospheres, found at a vast depth in the ocean, ii. 51

Cockle, structure and mode of life of the, ii. 230, 231

Codium, structure and habitat of, i. 219-224

Codium Bursa, structure of, i. 224

Codium tomentosum, structure of, i. 214

Coffee, active principle of, i. 428

Cohesion, properties of, i. 25 in solids, i. 25 in liquids, i. 25

267Cohesion: reciprocal attractions between solids and liquids, i. 25 instance of the power of the cohesive force, i. 91

Colchicum, or meadow saffron, mode of reproduction of, i. 388 poisonous alkaloid obtained from, i. 427

Collemacei, structure and habitat of, i. 307

Colloid bodies, i. 109, 110 less diffusible than crystalloids, i. 109 permeable to solutions of crystalloids, but impermeable to solutions of colloids, i. 110 characteristics of colloids, i. 111

Collomia grandiflora, fructification of, i. 380

Colocasia, water secreted by, i. 430

Colour, causes of, in flowers, green leaves, dyed cloth, gold, and copper, i. 35, 36

Colouring matter of flowers and plants, i. 428, 429

Comatula, structure of, ii. 175, 176

Combination, chemical, i. 94 the law of definite proportions, i. 94, 95 force of, i. 97, 98

Combustion, effect of, in the consumption of coal in the steam-engine, i. 29, 30 combustion a case of impetus, i. 30

Comets, spectra of, i. 159 note, 163

Conferva glomerata, development of, i. 207

Confervaceæ, habitat of, i. 206, 207 structure and development of, i. 207 reproduction of, i. 208 modes of action of the vital forces of, i. 210

Confervæ, cells and development of, i. 171

Confervæ, marine, structure, habitat, and reproduction of, i. 221, 222.

Conidium, or spore-dust cell, of fungi, i. 279

Coniomycetes, characters of the family of, i. 275

Conjugatæ, structure of the genus, i. 216

Conjugation, propagation of diatoms by, i. 200, 204

Constantinea rosa marina, i. 235

Constantinea sitchensis, i. 235

Copepoda, characters of the, ii. 204

Copper, properties of, i. 4 colour of, in reflected and absorbed light, i. 35, 36 its power of transmitting electricity, i. 90 atomic weight of, compared with that of hydrogen, i. 100 spectra of copper and its compounds, i. 145, 146

268Copper, peroxide of, combination forming, i. 104

Coral, structure of the coral polypes, ii. 133, 134 composition of the stony substance of, ii. 137 reef-building corals, ii. 138 red, ii. 125 white, ii. 127

Corallina officinalis, mode of reproduction of, i. 230 structure and development of, i. 240

Corallines, structure and mode of propagation of, i. 240

Corallium Johnstoni, structure and habitat of, ii. 127

Corallium rubrum, structure and mode of reproduction of, ii. 125, 126, 127 coral fishing in the Mediterranean, ii. 126

Corallium secundum, structure of, ii. 127

Cordyceps miliaris, characters of, i. 283, 293

Cordyceps purpurea, the second form of ergot, i. 293 structure of, i. 293

Cordyceps Robertsii, form of, i. 293

Coremium glaucum, production of, i. 287

Corolla of flowering plants, i. 378

Corundum, i. 4

Corynidæ, characters of the family, ii. 90

Cosmarium, structure and development of, i. 194

Cotton, dyes for, i. 125 necessity for mordants for fixing cotton dyes, i. 125 enormous manufacture of cotton in Britain, i. 125

Cowries, shells of, ii. 234, 235

Cow-tree, beverage obtained from the, i. 426

Crabs, structure and mode of reproduction of, ii. 189-197 hermit, structure of, ii. 197 king, fossil, ii. 211 spider, structure of, ii. 211

Creosote, i. 121 its property of preventing the decay of organic matter, i. 121

Cressylic acid, how produced, i. 120, 121 chemical composition of, i. 128

Cristallaria compressa, form of, ii. 28 structure of, ii. 39

Cristata, siliceous skeleton of, ii. 60

Crocus, structure and mode of reproduction of, i. 387, 388

Cruoria pellita, tetraspores of, i. 237

Crustacea, characters of the, ii. 188 fossil crustacea, ii. 211

269Crustacea, Decapod. See Decapods

Cryptogamia, spores of, i. 177, 178

Cryptonemiaceæ, multitude of forms of, i. 234 structure of, i. 234

Crystal, rock, its transmission of chemical solar rays, i. 65 absorption of invisible rays by, i. 65 change of position of the optical axes of the crystals of, by heat, i. 73

Crystallization, relation of polarization of light and heat to crystallization, i. 70, 71 axes of symmetry of crystals, i. 71, 72 change of position of the optical axes of crystals by heat, i. 72 effect of pressure on the optical axes of crystals, i. 73 influence on the aggregation of, i. 73, 74 probable origin of the crystalline form, i. 74 causes of the variety of forms assumed by matter, i. 74 deviation of dimorphous crystals from the general law of crystallization, i. 75 proof of the connection between the magnetic forces and crystalline structure, i. 76 conditions of the position which crystals take with regard to the magnetic force, i. 76

Crystalloids, or crystalline substances, diffusibility of, i. 109

Crystals, water an essential element in, i. 107 alterations in crystals by heat, i. 108

Cunina octonaria, larvæ of, parasites of the Turritopsis nutricula, ii. 100

Cusconine, structure of, and whence obtained, i. 427

Cuthbert’s, St., beads, ii. 175

Cutaneous diseases caused by fungi, i. 274

Cutleria multifida, structure, mode of reproduction, and habitat of, i. 248

Cuttle fish, structure of the, ii. 245-247

Cyanogen, combines with other substances and simple atoms, as if it were a simple element, i. 106 combination forming it, i. 106

Cyathea medullaris, used as food in New Zealand, i. 360

Cyatheæ, structure of, i. 360

Cyatheineæ, characters of the group, i. 344 sporangia of, i. 343 structure and fructification of, i. 360

Cycloclypeus, structure and habitat of, ii. 48

Cyclops quadricornis, structure and mode of reproduction of, ii. 205, 206

Cydippe pileus, structure of, ii. 101, 102

270Cymothea, their food and mode of taking it, ii. 203

Cyprææ, or cowries, shells of, ii. 234, 235

Cypris, structure and mode of reproduction of, ii. 207, 208

Cystopteris, characters and habitat of the genus, i. 348, 349

Cystopus candidus, or Uredo candida, structure, habitat, and mode of reproduction of, i. 278

Cystopteris fragilis, or brittle bladder fern, structure and habitat of, i. 349

Cystoseira, structure and habitat of, i. 255

Cystoseireæ, habitat of, i. 255

Cyttaria, the food of the Fuegians, i. 292 habitat of the, i. 292

D

Dactylocalyx pumiceus, spicula and skeleton of, ii. 60

Daphnia pulex, or arborescent water-flea, structure and mode of reproduction of, ii. 208

Dasya, structure of, i. 241, 242

Dasyglœa, structure of, i. 215

Datura sanguinea, intoxicating effect produced by a drink obtained from, i. 427

Davallia canariensis, or hare’s-foot fern, i. 351

Davallieæ, structure and habitat of, i. 350, 351

Dead bodies, agents in the decomposition of our, ii. 67

Decapoda, structure of, ii. 245

Decapods, tribes of the, ii. 188 characters of the, ii. 189

Delesseria alata, structure of, i. 243

Delesseria angustissima, structure of, i. 243

Delesseria sanguinea, structure and habitat of, i. 239

Dematiei, structure of, i. 283

Dendritina elegans, form of, ii. 28 structure of, ii. 32

Dendritine variety of the Peneroplis, characters and habitat of, ii. 32 fossils of, ii. 33

Dennstædtia, indusium of, i. 350

Deparia prolifera, sorus and indusium of, i. 350

Desmidiaceæ, structure and development of, i. 191 et seq. their habitat, i. 195

271Dextrine, production of in plants, i. 421

Dialysis, as a method of separating and analysing substances, i. 108 what constitutes dialysis, i. 110 Prof. Graham’s instrument for, i. 110 an extraordinary result of, i. 110

Diamagnetism, i. 75

Diamond, i. 13, 15 heat required to consume the, i. 15 crystallisation of the, i. 15 its resistance to electricity, i. 90

Dianthine, production of, i. 127

Diastase, production of, in plants, i. 420

Diatoma vulgare, structure and development of, i. 197

Diatomaceæ, or Brittleworts, found all over the globe, i. 196, 204 variety of forms of, i. 196 structure of, i, 197 development of, i. 200 social plants, i. 205 food for many aquatic animals, i. 205 fossil deposits of shells of, i. 206 enormous geological changes caused by, i. 206

Dicksonia antarctica, structure of, i. 349

Dicksonia lanata, structure of, i. 349

Dicksonia squarrosa, habitat of, i. 349

Dicksonieæ, i. 349 structure of, i. 350

Dicotyledonous, or exogenous, plants, structure and mode of reproduction of, i. 404-428

Dicranei, structure of, i. 329

Dictyopodium trilobum, structure and habitat of, ii. 20

Dictyota, structure of the genus, i. 246

Dictyota dichotoma, structure and mode of reproduction of, i. 247

Dictyoteæ, structure and mode of reproduction of, i. 246

Dictyurus purpurascens, structure of, i. 242

Difflugia, structure and minuteness of the shells of, ii. 22 their architecture, ii. 23

Difflugia pyriformis, structure, and habitat, and mode of propagation of, ii. 22, 23

Diffusibility, most substances differ in, i. 109 partial decomposition of definite chemical compounds by, i. 109 reciprocal diffusion of gases through porous plates, i. 111-113 the diffusing instrument used by Prof. Graham, i. 112

272Digestion, chemical powers causing, ii. 4

Dimorphism, contrasted with isomorphism, ii. 99

Diphyidæ, structure and habitat of the, ii. 103

Diplazieæ, characters of the group, i. 352

Diplazium, structure and fructification of, i. 352

Distillation, ordinary, i. 117 destructive, i. 117 of coal, i. 117

Distomata, characters of the, ii. 146

Dracæna Draco, or dragon tree of Teneriffe, i. 387

Drummond’s light, how produced, i. 30 the continuous spectra of, i. 132

Dry rot in wood, cause of, i. 266 on various substances, i. 285

Dulses, red, i. 235

Dumontia filiformis, structure of, i. 235

D’Urvillæa, structure, fructification, and habitat of, i. 256

Dyes obtained from aniline, i. 122-124 vegetable dyes, i. 124 mordants for cotton when dyed, i. 125 effects of electricity and the east wind on the process of dyeing, i. 126 obtained from preparations of petroleum, i. 127 obtained from lichens, i. 303 blue dye obtained from some club mosses, i. 374

E

Ear-shell, structure of the, ii. 234

Earth, quantity of heat which would be generated if it were arrested in its orbit, i. 27 and if it struck the sun, i. 28

Earth light, causes of, i. 68

Earth-worm, structure and food of the, ii. 151, 152

Echinodermata asteroïdea, structure, mode of reproduction, and habitat of, ii. 169-174

Echinodermata crinoïdea, or stone-lilies, structure, habitat, and mode of reproduction of, ii. 175, 176 fossil remains of, ii. 175

Echinodermata Echinoïdea, structure and mode of reproduction of, ii. 177-182

273Echinodermata: fossil Echinidæ, ii. 182, 183

Echinodermata Holothuroïdea, structure and mode of reproduction of, ii. 183

Echinodermata Sipunculidæ, characters of, ii. 186, 187

Echinodermata Synaptidæ, characters of the order of, ii. 184, 185

Echinus, structure of, ii. 176, 177

Echinus miliaris, spines of the, ii. 181

Ecklonia, structure and habitat of, i. 252

Ecklonia buccinalis, structure of, i. 250

Ectocarpeæ, form, structure, and habitat of, i. 244, 245

Ectocarpus pulsillus, fruit of, i. 245

Effusion of gases by pressure, i. 109, 110 Prof. Graham’s experiments, i. 113

Electricity, i. 30 permanent and regular current of, over the earth, in the atmosphere and in the surface of the earth, i. 31 thunder and lightning, i. 31 force exerted in the creation of the deep, i. 31 the voltaic battery and the electro-magnetic induction apparatus, i. 31, 32 reciprocity of action of electricity and heat, i. 31 electricity produced by chemical action, and conversely, i. 32 intensity of the light and heat of the electric spark, i. 32 produced by fifty Bunsen elements, i. 32 conducting power of charcoal, i. 32 air and glass non-conductors, i. 32 proof of the correlation of heat and electricity, i. 33 motion of the atoms of a conducting wire during the passage of an electric current, i. 33 effect on a conducting wire of an invariable transit of electricity sent from the same pole of an inductive apparatus, i. 33 difference between electric and magnetic currents, i. 33 influence of electricity on the aggregation of matter, i. 74 ratio between the specific heat and weight of the atoms of matter, i. 74 influence of magnetism on the stratified appearance of the electric light, i. 78 extreme heat and light of electric discharges, i. 84 the arc discharge, i. 84 cause of the stratified discharge, i. 85 effect of varied intensity on electric discharges, i. 86, 87 effect of varied resistance on electric discharges, i. 88, 89 varied facility with which substances transmit electricity, i. 90 274illustration of the action of electricity and magnetism on light, i. 90 instances of the correlation of electricity and heat, i. 91 voltaic electricity, and its combination and resolution of substances according to the law of definite proportions, i. 94 Faraday’s law of the quantity of electricity required to separate and unite the same atoms, i. 94 superiority of voltaic over static electricity, i. 95 electricity the most powerful instrument of analysis, i. 95 capacity of atoms for electricity, i. 100 a given quantity of electricity required to separate combined substances into their component parts, i. 101 spectrum analysis of the electric spark, i. 138 development of electricity in plants and flowers, i. 430 electric currents in the nerves and muscles of animals, ii. 7

Electro-chemical action in heterogeneous atoms of matter, i. 95

Electro-magnetic induction apparatus, i. 31 Ruhmkorff’s, i. 32

Elvellacei, characters of the, i. 290

Empusa Muscæ, or fly fungus, i. 274

Encalypta vulgaris, organs of fructification of, i. 326

Encrinites, structure of, ii. 175

Endocarpei, structure and habitat of, i. 310

Endocarpon lacteum, structure and organs of reproduction of, i. 299

Endogenous plants, i. 383-403

Enteromorpha, characters of the genus, i. 223

Enteromorpha intestinalis, structure and habitat of, i. 223, 224

Entomostraca, characters of the, ii. 203

Entophytes, characters of the group of, i. 275, 276 sporangia, or spore-cells, of, i. 279

Entozoa, characters of the order of, ii. 144 transformations of the young of the, ii. 146

Eolis, the crowned, structure of, ii. 240, 241

Eozoön Canadense, may be regarded as the first appearance of animal life upon the earth, ii. 54 found in fundamental quartz rocks, ii. 54 structure of, ii. 55 range of its existence, ii. 56

Epipactis palustris, structure and mode of reproduction of, i. 397, 398

Epiphytes, characters of the group of, i. 275

Epithemia, mode of development of, i. 202

Epizoa, or suctorial crustacea, structure, habitat, and mode of reproduction of, ii. 212

275Equisetaceæ, or horse-tails, characters of, i. 367 contrasted with ferns, i. 369 large quantity of silex in, i. 369 size and habitat of fossil and existing species, i. 369

Equisetum giganteum, structure and fructification of, i. 368

Ergot, Cordyceps the second form of, i. 293

Errantia, structure and habitat of the, ii. 156, 157, 161

Erysiphe, mildew formed by, i. 295

Eschara, structure of, ii. 218

Ether, sulphuric absorption of radiant heat by, i. 40

Eucamptodon perichætialis, leaves of, i. 330

Eucyrtidium, structure of, ii. 20

Euglena acus, structure of, ii. 72

Euglena sanguinea, structure of, ii. 72

Euglena, structure of the genus, ii. 72

Euglyphæ, structure and habitat of, ii. 22

Eunice, structure of, ii. 157 mode of reproduction of, ii. 160

Euparmeliaceæ, characters of the group, i. 304

Euphorbiaceæ, or spurgeworts, poisons and food supplied by the, i. 425, 426

Evernia flavicans, colour of, i. 303

Evernia jubata, structure of, i. 302

Evernia vulpina, i. 303 brown dye obtained from, i. 303

Exchange, law of, i. 35 independent proofs of the, i. 35, note

Exidia Auricula Judæ, or Jew’s Ear fungus, structure and fructification of, i. 266

Excœcaria Agallocha, poison of the, i. 426

Exogenous plants, i. 404-408

Eyes of man, fungi in, i. 275

F

Fairy rings of the fields, i. 262

Faujasina, structure of, ii. 45

Felspar, fluorescence of, i. 66

Fermentation, fungi producing, i. 286-288 minuteness and lowness of organization of the ferments, ii. 68 habitat of the, ii. 68

Fibrin, formation and structure of, in vegetable organisms, i. 423

276Fig, common, juices of fruit of, changed into sugar, i. 426 poison of the white juice of the, i. 426

Filariæ, 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, phosphorescence 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 phosphorescence, 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

277Fly fungus, i. 274

Fontinalei, structure and habitat of, i. 331

Food, miraculous descent of, i. 305 lichens as, i. 305, 308 importance of, to the animal frame, ii. 3

Foot-pound, the, of Mr. Joule, i. 26 unit of mechanical force, i. 26

Foraminifera, structure and geological importance of, ii. 27 various forms of, ii. 28 order of porcellanous foraminifera, ii. 30 order of arenaceous foraminifera, ii. 36 order of vitreous foraminifera, ii. 37 abundance of fossil foraminifera in the sedimentary strata, ii. 52 mode of obtaining casts of, ii. 53 comparison of foraminifera recent and fossil, ii. 53 the Eozoön Canadense, ii. 54 the Carpenteria a link between the foraminifera and sponges, ii. 57

Force, i. 23 store of, eternal and unchangeable, i. 24, 25 cohesion, i. 25 in solids, i. 25 in liquids, i. 25 reciprocal attraction between solids and liquids, i. 25 unit of mechanical force, i. 26 heat generated by impetus, i. 27 unit, or mechanical equivalent of heat, i. 29 combustion a case of impetus, i. 30 energy existing in the coal fields on the globe, i. 30 magnetism and electricity, i. 30 influence of force on the aggregation of matter, i. 73 power of electricity in this respect, i. 74 relations between the force of magnetism and atoms of matter, i. 75 effect of the physical forces on molecular arrangement, i. 91 electricity, i. 91 motion, i. 91 catalysis, i. 91 force of chemical combination, i. 97, 98 relation between chemical affinity and mechanical force, i. 98

Formic acid, synthetical formation of, i. 424

Fragillaria, development of, i. 201

Fraunhofer’s lines, i. 129

278Frond, 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

Fuci, sexual fructification of, i. 253

Fucoideæ, habitat of some, i. 256

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

Fuegians, staple food of the, i. 292

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

G

Galeolaria lutea, structure, development, and mode of reproduction of, ii. 107, 108

Garancine, from what obtained, i. 124

Gas coal. See Coal gas.

Gases, absorption and radiation of radiant heat by gases and vapours, i. 38 279relation 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

280Gasteromycetes, characters of the family, i. 267

Gastropoda, structure of the shells of, ii. 234 structure of the animal, ii. 235 tongue of the, ii. 239

Gelidiaceæ, structure and mode of propagation of, i. 238

Gelidium corneum, structure and mode of propagation of, i. 238 form of, i. 243

Gems, crystals of, formed artificially by electricity, i. 74

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

Glass, a non-conductor of electricity, i. 32 property of, in regard to the transmission of light, i. 36 impervious to chemical solar rays, i. 63

Gleichenineæ, sporangia of, i. 34 structure and habitat of, i. 344, 360

Globigerina bulloïdes, form of, ii. 28

Globigerina, structure of the genus, ii. 40, 41

Globigerinæ, abundance of at vast depths in the ocean, ii. 49-51

Globigerinidæ, characters of the family of, ii. 40

Glycerine, chemical combination forming, i. 97

Glyphidei, characters of the order, i. 309

Glucinum, i. 4

Gold, colour of, in reflected and in absorbed light, i. 35, 36 crystals of, formed artificially by electricity, i. 74

Gonidia, propagation of diatoms by, i. 202, 204 of lichens, i. 300

Goniometer, i. 38

Gorgonia graminea, structure and habitat of, ii. 124, 125

Gorgonia verrucosa, structure, habitat, and mode of reproduction of, ii. 124

Gorgoniidæ, structure and mode of reproduction of, ii. 123, 124 the three natural groups of, ii. 124

Gracilaria compressa, i. 239

Gracilaria lichenoides, or Ceylon moss, i. 239

Gracilaria armata, mode of reproduction of, i. 230

Graminaceæ, structure and mode of reproduction of, i. 385, 386

Grammatophora serpentina, structure and development of, i. 197

Graphidei, characters of the order, i. 308 habitat of the, i. 309

Graphite, form of the crystals of, i. 15 natural, little or no porosity of, i. 112 porosity of artificial graphite, i. 112

Grasses, silica in the stalks and leaves of the, i. 17

281Grasses, structure and mode of reproduction of, i. 385-387

Gravitation, force of, less powerful than that of molecular attraction, i. 109

Gravity, specific, of atoms, i. 100

Green dye, obtained from the buckthorn, i. 124

Griffithsia, structure, habitat, and organs of reproduction of, i. 233

Grimmiei, structure of the tribe, i. 329

Grinnelia americana, structure and mode of reproduction of, i. 230, 239

Gromia oviformis, structure of, ii. 26, 27

Gromiæ, structure of the genus, ii. 25-27

Guano, mauve dye obtained from, i. 125

Guernsey, richness of the iodine obtained from the sea-weeds of, i. 258

Guinea worm, structure and mode of reproduction of, ii. 147

Gums, formation of, i. 422

Gymnogramma rutæfolia, remarkable distribution of, i. 336

Gyrophora, structure of the genus, i. 308

H

Hairs of plants, structure of, i. 411

Halichondria panicea, mode of propagation of, ii. 60, 61

Haliomma, structure of, ii. 21

Haliotis splendens, or ear-shell, structure of, ii. 234

Haliseris, structure of, i. 247

Halogens, spectra of the, i. 146

Halurus, structure and mode of propagation of, i. 233

Hare’s-foot fern, i. 351

Hart’s-tongue fern, caudex of, i. 340 structure, habitat, and fructification of, i. 351, 352

Heart, and organs representing it in the lower animals, ii. 4

Heat generated by impetus, i. 27 quantity of heat which would be generated if it were arrested in its orbit, i. 27 probable cause of the heat of the sun, i. 28 effect of the absorption of heat on a body in expansion and contraction, i. 28 specific heat, i. 28 mechanical equivalent of heat, i. 29 causes of the heat which is the motive force of the steam-engine, i. 29 reciprocal action of heat and electricity, i. 31 282intensity of the heat of the electric spark, i. 32 proof of the correlation of heat and electricity, i. 33 constancy in the amount and refrangibility of the light and heat absorbed and radiated, i. 34 property of some substances in the transmission of heat, i. 36 substances which transmit radiant heat freely but radiate badly, and vice versâ, i. 37 Tyndall’s experiments on the radiation and absorption 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 absorption of radiant heat by the vapours of volatile liquids, i. 40 Prof. Tyndall’s experiments showing the radiation to be equal to the absorption of radiant heat, i. 46 action of different thicknesses of the same gas or vapour on radiant heat, i. 47 dynamic absorption and radiation, i. 49 dynamical evolution of heat, i. 52 experiment illustrating the change of heat into light, i. 62 polarization of heat and light, i. 68, 69 by reflection and refraction, i. 69 effect of heat on the magnetism of iron, nickel, and cobalt, i. 77 extreme heat and light of electric discharges, i. 84 instances of the correlation of electricity and heat, i. 91 capacity of atoms for heat, i. 100 Mr. Croll’s experiments, i. 101 effects of heat on vegetation, i. 169 large amount of heat evolved by vegetables, i. 265 cause of animal heat, ii. 63

Helix, or snail, tentacles of, ii. 236

Helix aspersa, structure of the tongue of, ii. 237

Helix pomatia, teeth of, ii. 237

Hellebore, white, poisonous alkaloid of, i. 427

Helmet shell, structure of, ii. 234

Helminthosporium Hoffmanni, spores of, i. 285, 286

Helminthosporium nodosum, spores of, i. 286.

Helvella, structure and habitat of, i. 291

Hepaticæ, or liverworts, characters of the, i. 316

Hepialus virescens of New Zealand, Cordyceps Robertsii of the, i. 293

Herschel, Sir W., his discovery of invisible rays of light of high heating power, i. 36

Hewardia, structure of, i. 359

283Himanthalia lorea, structure, fructification and habitat of, i. 256

Holly fern, structure of, i. 347

Holothuridæ, or sea-cucumbers, structure and mode of reproduction of, ii. 183-186

Hop, fungus constituting the mildew of the, i. 295

Hormosiphon arcticus, wide distribution of, i. 212

Hormotrichum, structure of the genus, i. 222

Hormotrichum collabens, structure and mode of reproduction of, i. 222

Hyacinth, structure and mode of reproduction of the, i. 388

Hyalæa, structure of the, ii. 242

Hydra fusca, structure and mode of propagation of, ii. 84, 85

Hydra viridis, structure and mode of propagation of, ii. 85

Hydra vulgaris, structure and mode of propagation of, ii. 85

Hydræ, structure of, ii. 81, 84 mode of propagation of, ii. 84 compound fresh-water Hydræ, ii. 85 development of medusa-buds, ii. 95 alternation of generation of hydræ and medusæ, ii. 96

Hydraulic machine, bog moss acts as a, i. 333

Hydridæ, characters of the group, ii. 81

Hydrobromic acid, amount of absorption of radiant heat by, i. 42

Hydrochloric acid, absorption of radiant heat by, i. 41, 42

Hydrodictyon utriculatum, structure and habitat of, i. 211 reproduction and development of, i. 211

Hydrofluoric acid, i. 18

Hydrogen gas, i. 11 affinity of chlorine for hydrogen, i. 19 absorptive power of, i. 39, 41 proportion of hydrogen to oxygen in the composition of water, i. 94 will not combine with carbon, i. 97 weights of the atoms of, as compared with those of oxygen, i. 99 probable cause of its greater cooling power than that of oxygen, i. 115 one of the illuminants in coal gas, i. 118 spectrum analysis of, i. 139, 144 and of hydrogen, carburetted and attenuated, during and after decomposition, i. 141 carburetted, one of the illuminants in coal gas, i. 118 marsh-gas and fire-damp, i. 118 peroxide of, i. 9 combination forming, i. 104 284combines with other substances and simple atoms as if it were a simple element, i. 106 sulphuretted, amount of absorption of radiant heat by, i. 41 opacity of, to the invisible rays, i. 65 one of the illuminants in coal gas, i. 118 how freed from coal gas, i. 118

Hydrozoa, campanograde, characters of, ii. 103 ciliograde, characters of the, ii. 101 mode of reproduction of, ii. 103 oceanic, structure of, ii. 81, 86 compound oceanic, structure of, ii. 87 medusiform zooids, ii. 88, 89 mode of reproduction of, ii. 89, 90

Hymenomycetes, family of, i. 261

Hymenophyllum, stem of, i. 339

Hymenophyllum tunbridgense, or film fern, structure and habitat of, i. 362

Hymenophyllum unilaterale, habitat and structure of, i. 362

Hyphomycetes, characters of the family, i. 282

Hypogæi, structure and fructification of the subterranean sub-order of, i. 267, 268

Hyponitrous acid, combination forming, i. 95

Hypopterygium Smithianum, leaves of, i. 330

I

Ice, absorption of invisible rays by, i. 65 believed to be a colloid body, i. 111

Iceland moss, characters of, i. 304

Iceland spar, polarization of light and heat in, by refraction, i. 69 change of position of the optical axes of the crystals of, by heat, i. 73

Ileodictyon, eaten as food, i. 268

Impetus, i. 26, 27 heat generated by, i. 27 combustion a case of, i. 30

Indian rubber, dissolved by naphtha for waterproofing, i. 120

Indium, discovery of the metal so called, i. 137 properties of, i. 137

Infusoria, structure, form, and habitat of, ii. 63 abundance of infusoria in the atmosphere, ii. 63, 64 different states of development in one and the same animal, ii. 65 285groups of, of opposite characters in the same liquid, ii. 66 the agents in the decomposition of animal matter, ii. 67 minuteness of the ferments, ii. 68 cilia of Infusoria, ii. 68 as organs of locomotion, ii. 69 cell constituting the body of Infusoria, ii. 70 food and organs of digestion of, ii. 70 transparent contractile vesicles, ii. 71 modes of propagation, ii. 74 et seq. in a state analogous to hybernation, ii. 78, 79 functions assigned to Infusoria in the economy of nature, ii. 79

Insects, phosphorescence of, i. 167

Intelligence, or the mental principle, of animals, ii. 11, 12

Iodine, i. 18, 21 whence obtained, i. 19 properties of, i. 21, 22 spectrum of, i. 21 atomic weight of, compared with that of hydrogen, i. 100 preparation of, from sea-weeds, i. 128 spectrum analysis of, i. 140, 141 iodine richer at Guernsey than elsewhere, i. 258

Iris germanica, vertical section showing the cellular tissue of, i. 173

Iron heated by percussion or impetus, i. 27 effect of electricity on, i. 32 effect of magnetism of, i. 75, 76, 77 and of heat on the magnetism of, i. 77 feeble affinity of iron for mercury, i. 98 atomic weight of, compared with that of hydrogen, i. 100 spectrum analysis of the rarefied vapour of, i. 142

Isaria, its structure and habitat, i. 282 its destruction of caterpillars, i. 282, 293

Isaria crassa, characters of, i. 283

Isaria farinosa, characters of, i. 283

Isariacei, structure and habitat of, i. 282

Isidæ, structure, habitat, and mode of reproduction of, ii. 125

Isis, structure of the genus, ii. 125

Isomeric substances, i. 104 law of the sequence of three isomeric bodies, and their respective atomic numbers, i. 105

Isomorphism, property of, in determining atomic weights, i. 99

Isomorphous substances, conduct of, under magnetic influence, i. 76

Isopoda, characters of the order, ii. 202

286J

Jam, greenish, and grey moulds on, i. 285

Jungermanniaceæ, or scale mosses, structure, fertilization, and development of, i. 320-322

Jupiter, the planet, spectrum of, i. 157, 161 constitution of, i. 158

K

Katsup made from the morel, i. 292

Kelp, i. 258 former and present uses of, i. 128

Kerona silurus, structure and food of, ii. 69

L

Labellum of orchids, i. 401

Lactarii, laticiferous vessels of, i. 263

Lady Fern, herbaceous caudex of, i. 340 structure and fructification of, i. 352, 353

Lagenidæ, characters and habitat of the family, ii. 39

Lagoons formed by corals, ii. 140-143

Laminaria bulbosa, structure and fruit of, i. 248

Laminaria debilis, structure of, i. 248

Laminaria digitata, or oar-weed, structure of, i. 249 richness of the iodine obtained from, at Guernsey, i. 258

Laminaria radiata, structure, habitat, and fructification of, i. 250

Laminaria saccharina, or devil’s apron, structure and mode of reproduction of, i. 249

Laminariæ, submarine forests of, i. 248

Lanosa nivalis, the probable cause of the mildew in rye, i. 297

Lastrea, structure of the genus, i. 346

Lastrea æmula, structure of, i. 346

Lastrea filix-mas, structure of, i. 340

Lastrea rigida, scent of, i. 347

Lastrea Thelypteris or marsh fern, structure of, i. 346

Latex, structure of the, in plants, i. 417

287Laughing-gas, or protoxide of nitrogen, combination forming, i. 95

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

Laurencia dasyphylla, antheridia of, i. 241

Laurencia pinnatifida, or pepper dulse, structure, habitat, and mode of propagation of, i. 241

Laurencia tenuissima, antheridia of, i. 241

Laurenciaceæ, characters of, i. 240, 241

Laurentian system, ancient formation of the crystallized limestone near the base of the, ii. 54

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

Lead, its resistance to electricity, i. 90 chloride of, spectrum of, i. 146

Leathesia, structure of, i. 245

Leaves of plants, structure and functions of, i. 410

Lecanora affinis, section of, i. 300 structure and habitat of, i. 305

Lecanora esculenta, habitat of, i. 305

Lecidea, characters of the genus, i. 306

Lecidea geographica, great age of, i. 306

Lecidinei, characters of the order, i. 306

Leeches, structure of, ii. 149-151

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

Lepadidæ, structure of, ii. 213, 215

Lepas anatifera, structure and mode of reproduction of, ii. 215

Lepidodendron, structure of the fossil, i. 375

Lepidostrobus ornatus, structure of, i. 375

Lepraliæ, structure of, ii. 219

Leptopteris, characters of, i. 364

Lessonia, arborescent, forests of, i. 251

Lessonia nigrescens, structure of, i. 251 rings of growth of, i. 252

Leucobryum, structure of, i. 329

Leucobryum glaucum, leaves of, i. 330

Leveillea, structure of, i. 242

Libanea crab, a parasite of the medusæ, ii. 100

Lichens, characters and habitat of, i. 298 two groups of—Gymnocarpei and Angiocarpei, i. 299 horizontal lichens, i. 299 gonidia, i. 300 asci, i. 301 thallus or frond, i. 301 dyes obtained from, i. 124, 303 288brilliancy of the colours of, i. 304

Lichina, characters of the genus, i. 310

Lichinei, characters of the group, i. 310

Life, the mystery of, i. 97 instances of individual combined with a common life in the lower orders of animals, ii. 38

Light, probable cause of the, of the sun, i. 28 Drummond’s light, how produced, i. 30 intensity of the, of the electric spark, i. 32 chemical action of, i. 34 amount of force exerted by the sun’s light within the limits of the terrestrial atmosphere, i. 34 constancy of the amount and refrangibility of light and heat absorbed and radiated, i. 34 causes of colour of flowers, leaves, dyed cloth, and gold and copper, i. 35, 36 property of some substances in the transmission of radiant light and heat, i. 36 invisible rays of high heating power existing beyond the red end of the solar spectrum, i. 36 Melloni’s investigation of the laws of radiation and absorption of radiant heat in solid and liquid matter, i. 38 chemical power of the light of the moon and stars, i. 55 and of solar light, i. 56 effect of the opalescence of the atmosphere on the light of the sun, i. 55 probable causes of the blueness of the sky, and the brightness of the tints at sun-rise and sun-set, i. 58 solar spectrum, i. 58 myriads of ethereal waves constituting the seven colours of the, i. 58 fluorescent or degraded light, i. 60 experiment illustrating the change of heat into light, i. 62 absorption of invisible rays, by solids, liquids, and gases, i. 65 causes of earth light, i. 66 polarization of light and heat, i. 68, 69 by reflection and refraction, i. 69 relation of polarization to crystallization, i. 70, 71 M. Gassiot’s experiments on stratified electric light, i. 78 influence of magnetism on the stratified light, i. 78 cause of the stratified discharge, i. 85 effect of varied intensity on electric discharges, i. 86 289action of magnetism and electricity on light, i. 90 delicate power of analysis in light, i. 95 Dr. Young’s establishment of the undulatory theory of light, i. 129 Drummond’s light, i. 132 coloured light obtained from the combustion of the salts of different metals, i. 132 effects of light on vegetation, i. 168, 169 effects of light as an exciting cause in the vegetable world, i. 431

Lightning, spectrum of, i. 147

Ligneous tissue, i. 174, 175

Liliaceæ, structure and development of the, i. 388

Limboriei, structure and habitat of the, i. 310

Lime, carbonate of, different modifications assumed by, i. 74 chloride of, properties of, i. 19 oxalate of, formation of, i. 117

Limestones, probable history of the oldest, ii. 52 the nummulitic, ii. 53 the limestone formed by the Eozoön Canadense, ii. 54

Limnoria lignorum, structure of, ii. 203

Limpet, structure, food, and habitat of, ii. 238, 239

Limulus, fossil remains of, ii. 211

Lindsæeæ, characters of, i. 351

Lingbya, structure of, i. 213

Lingula flags, fossil animals composing the, ii. 53

Listera ovata, structure and mode of reproduction of, i. 399

Lithium, i. 3 spectrum analysis of, i. 133 existence of lithium in all three kingdoms of nature, i. 134 spectrum analysis of the rarefied vapour of, i. 142 effect of high temperature, i. 142, 143 chloride of, spectrum of, i. 146

Litmus, or orchil, from what obtained, i. 124, 303

Lituola, structure of the genus, ii. 37

Lituolidæ, characters of the family of, ii. 36, 37

Liver worts. See Hepaticæ

Lobophylla angulosa, structure of, ii. 135, 136

Locomotion of some diatoms, i. 204

Lo-hao, a Chinese green dye, i. 124

Loligo vulgare, or squid, structure of, ii. 245, 246

Lomaria, characters of the genus, i. 357

Lomariopsis, characters of, i. 360

Loxades bursaria, structure of, ii. 72

290Loxades bursaria, mode of propagation of, ii. 75

Lucifer, characters of the genus, ii. 200 matches, i. 17

Luminosity of the medusæ in warm seas, ii. 99 of Annelida, ii. 160 of Pyrosomidæ, ii. 226

Lycoperdon giganteum, structure, habitat, and fructification of, i. 267

Lycoperdon, structure and fructification of, i. 267

Lycopodiaceæ, or club mosses, characters of, i. 373 habitat and fructification of, i. 373, 374 uses to which they have been applied, i. 374

Lycopodium, or wolf’s-claw, characters of the genus, i. 374

Lycopodium clavatum, structure and habitat of, i. 374 inflammability of the dried spores of, i. 374

Lycopodium inundatum, structure and habitat of, i. 374

Lygodium articulatum, structure of, i. 363

Lymnæa, or pond snail, distoma of the, ii. 146

M

Macrocystis pyrifera, structure, habitat, and fructification of, i. 250

Macrura, characters of the, ii. 189 fossil remains of, ii. 211

Madder, dyes obtained from, i. 124, 125

Magenta, or aniline red, Dr. Hofmann’s discovery of, i. 122 how produced, i. 122 purple dye produced by mixing it with aniline, i. 123

Magnesium, i. 3, 4 spectrum of, i. 65 spectrum analysis of the rarefied vapour of, i. 142 shown to be one of the metals existing in the sun, i. 151-153 spectrum of the light of a magnesium flame, i. 153, 154 its use in photography, i. 154

Magnetism, i. 30 periodic and secular variations of, i. 30 probably stand in some periodic connection with the solar spots, i. 30, 31 probable cause of terrestrial magnetism, i. 31 difference between magnetic and electric currents, i. 33 291relations between the force of magnetism and the atoms of matter, i. 75 all substances either magnetic or diamagnetic, i. 75 proof of the connection between the magnetic forces and crystalline structure, i. 76 conduct of amorphous and isomorphous substances under magnetic influence, i. 76 action of magnets upon matter most powerful in the line of maximum density, i. 76 conditions of the position which crystals take with regard to the magnetic force, i. 76 magnetic changes in the relations and distances between the ultimate atoms of matter, i. 77 effect of magnetism on the stratified appearance of the electric light, i. 78 causes of the polarity of a magnet, according to Ampère, i. 80 action of magnetism on the stratified discharges of electric light, i. 82 illustration of the action of magnetism and electricity on light, i. 90

Maiden’s hair fern, structure and habitat of, i. 359

Malaxis paludosa, or bog malaxis, structure and mode of reproduction of, i. 400

Malic acid, chemical combination forming, i. 97

Manchineel, poison of the, i. 426

Manganese, peroxide of, relative weight of the atoms of oxygen and metal in, i. 99 atomic weight of, compared with that of hydrogen, i. 100 peroxide of, combination forming, i. 104

Manihot, or Cassava, food obtained from the, i. 426

Marasmius Oreades, spawn of, i. 262

Marattia salicina used as food, i. 365

Marattiaceæ, characters of the group, i. 364

Marchantia polymorpha, structure, development, fructification, and habitat of, i. 317-320

Marchantiaceæ, characters of the order, i. 317

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

Marsh-gas, i. 118 amount of absorption of radiant heat by, i. 41

Marsilea, characters of the genus, i. 372

Marsileaceæ, or Rhizospermæ, characters of the tribe, i. 371

Matonineæ, characters of the group, i. 344

Matter, molecules of, i. 2 292agency of electricity in the chemical composition and decomposition of, i. 32 decomposing and elective power of, i. 35

Mauve, Dr. Hofmann’s discovery of the aniline colour, i. 122 at first made from orchil, i. 124 derived from guano, i. 125

Mediterranean sea, zones of algæ in the, i. 259 foraminifera, the ooze in the bed of the, ii. 51

Medusæ, form and structure of, ii. 91

Medusæ, pulmograde, form and structure of, ii. 91, 92 naked-eyed medusæ, ii. 91-96 mode of reproduction of, ii. 94 armed or stinging medusæ, ii. 99 luminosity of, in warm seas, ii. 99 development of medusa-buds, ii. 96 alternation of generation of hydræ and medusæ, ii. 96 covered-eyed medusæ, ii. 97 parasites of, ii. 99 abundance of species of, ii. 100 food of medusæ, ii. 101

Medusa-buds, development of, ii. 95

Medusiform zooids of hydrozoa, ii. 88, 89

Melanconiei, characters of the group of, i. 281, 282

Melanogaster, the red truffle of Bath, i. 268

Melanospermeæ, characters of, i. 181 marine forests of, i. 244 structure of the, i. 244, et seq.

Mercury, conditions under which he may be habitable, i. 55

Mercury, its feeble affinity for iron, i. 98

Meridion circulare, structure and development of, i. 200, 201

Merulius lacrymans, the cause of dry rot in wood, i. 266

Mesocarpus, reproduction of, i. 217

Mesogloias, structure of, i. 245

Metals and their properties, i. 3 alkaline metals, i. 3 of alkaline earths, i. 3 from non-alkaline earths, i. 4 avidity of some of them for oxygen, i. 4 metals whose oxides are not reducible by heat, i. 4 diatomic metals, i. 4 triatomic metals, i. 5 conduction of heat and radiation, i. 5 293vaporization, i. 5 spectra of volatilized metals, i. 64 coloured light obtained from the combustion of the salts of different metals, i. 132 spectrum of, not always the same, i. 145 number of the metals of which the spectra has been determined i. 147 metals shown to exist in the sun, i. 151-153 and not to exist in it, i. 154 metals contained in every plant, i. 414

Meteorites probably not of solar origin, i. 153

Mica, opacity of, to the invisible rays, i. 65

Mignonette, weight of the perfume of, i. 45

Mildew of the vine, hop, &c., i. 295 the black mildews of the Azores and Ceylon, i. 297

Miliola, structure and habitat of, ii. 30 abundance of, in the seas of the Eocene period, ii. 31

Miliolidæ, characters of the order, ii. 30

Milk sap of plants, i. 425 vessels of plants, i. 417

Milleporæ complanata or palmipora, structure of, ii. 141

Mimosa pudica, irritability of the tissues of, i. 432

Mind and matter connection between, ii. 5

Molecules of matter, i. 2 cohesion of, i. 25 unit of mechanical force, i. 26 causes of the ethereal undulating motions of, i. 34, 35 See Atoms

Mollusca, structure, habitat, and mode of reproduction of, ii. 229, et seq. shells of the, ii. 232 naked, ii. 240 winged, ii. 240

Monas corpusculus, extreme minuteness of, ii. 63, 67 and of its ova, ii. 67

Monocotyledonous, or endogenous plants, structure, growth, and reproduction of, i. 383 seeds of this class, i. 383 stems, or axes, i. 384 remarkable plants belonging to the monocotyledons, i. 387

Monostoma, or one-mouthed medusæ, structure and mode of reproduction of, ii. 97

Monormia, habitat and structure of, i. 212

294Moon, interception of the heat radiated by the full, by the earth’s atmosphere, i. 55 its effect on the higher regions of the atmosphere, i. 55 chemical power of the moon’s light, i. 55

Moonstone, or adularia, fluorescent property of, i. 66

Moonwort, structure, and habitat of, i. 366

Morchella esculenta, the morel, i. 291 katsup made from, i. 292

Mordants for fixing dyes in cotton cloth, i. 125

Morphine, the probable narcotic principle of opium, i. 427

Mother-of-pearl, composition of, ii. 234

Motion, effect of, on molecular arrangement, i. 91

Moulds, fungus, on various substances, i. 285

Mucedines, structure of the, i. 283 the origin of all fermentation, i. 289

Mucorini, or moulds, structures of the, i. 296 habitat of the, i. 296, 297

Muriatic acid, formation of, i. 20 action of, upon ammonia, i. 120

Musci, or Mosses, structure and mode of reproduction of, i. 3 antheridia of, i. 324 sporangia of, i. 325 gemmæ or buds, i. 327 leaves of, i. 330 aquatic mosses, i. 331 peat, i. 333 uses of mosses, i. 334

Muscle, structure and functions of, ii. 2 functions of the muscles, ii. 5 electric currents formed in the muscles, ii. 7 muscular respiration, ii. 8

Mushrooms, i. 261 mycelium, or spawn, i. 262

Musk, power of absorption of radiant heat by the perfume of, i. 45

Mussel, structure of the gills of the common, ii. 230

Mycelium or mushroom spawn, i. 261, 262

Mysis, or opossum shrimps, structure of, ii. 199

Myxogastres, structure, habitat, and reproduction of, i. 269, 270 their Amœba-like motions, i. 270

295N

Naïs, structure and habitat of the, ii. 152, 153

Naphtha, manufacture of, i. 120 uses to which it is applied, i. 120 sources of, in various parts of the world, i. 126 naphtha procured by the distillation of petroleum, i. 127

Naphthalin, production of, i. 127

Narcotics, exciting, known to almost all people, however savage, i. 427

Navicula, structure of, i. 198

Naviculæ, spontaneous locomotion of, i. 202

Nebulæ, spectra of various, i. 158-160, 163 constitution of the, i. 163 probable existence of primordial nebulous matter according to the theories of Sir W. Herschel and La Place, i. 164

Nectria, characters of the genus, i. 295

Nectria Peziza, structure of, i. 295

Nematoid entozoa, structure and mode of reproduction of, ii. 146

Nemertes gigas, or great band worm, nervous system of, ii. 158

Neotteæ, characters of the British tribe of, i. 397, 398

Neottia Nidus-avis, structure and mode of reproduction of, i. 400

Nephrolepis tuberosa, characters and habitat of, i. 348

Nereis, structure of, ii. 157

Nereis diversicolor, mode of reproduction of, ii. 160

Nereocystis Lutkeana, structure and habitat of, i. 249

Nerve-force of animals, ii. 4, 6 chemical powers generated by, ii. 6

Nerves of animals, structure and functions of, ii. 5 electric currents in the, ii. 7 structure and functions of the brain and spinal cord, ii. 8 the nervous systems of the higher and lower animals, ii. 9-11

Nervous system of animals, ii. 5

Nickel, i. 4, 5 crystals of, formed artificially by electricity, i. 74 effect of heat on the magnetism of, i. 77 atomic weight of, compared with that of hydrogen, i. 100

Nidulariacei, characters of the order of, i. 272, 273 structure and mode of reproduction of, i. 273 habitat of, i. 273

Nitella flexilis, structure and mode of reproduction of, i. 312

Nitophyllum, structure and fronds of, i. 238, 239

296Nitric acid, combination forming, i. 95

Nitrogen gas, i. 12 combination of nitrogen with chlorine, i. 20 absorptive power of, i. 39, 41 fulminates compounds of, i. 92 number of combinations of, with oxygen, i. 95 atomic weight of, compared with that of hydrogen, i. 100 one of the illuminants in coal gas, i. 118 spectrum analysis of, i. 140, 145 in high temperature, i. 144 binoxide of, combination forming, i. 95 chloride of, catalysis of, i. 91 iodide of, catalysis of, i. 91 protoxide of, or laughing gas, combination forming, i. 95

Nitrous oxide, absorption of, radiant heat by, i. 41, 43 combination forming, i. 95

Noctiluca miliaris, structure and mode of propagation of, ii. 73, 74

Noctiluci, their food, i. 205

Nodosaria, characters of the genus, ii. 39

Nodosaria rugosa, shell of, ii. 28 structure of, ii. 39

Nodosaria spinicosta, form of, ii. 28 structure of, ii. 39

Nostoc commune, wide distribution of, i. 212

Nostochineæ, structure and habitat of, i. 211 reproduction of, i. 212 wide distribution of, i. 212

Nullipores, structure and habitat of, i. 142

Nummulites, structure of the, ii. 44-46 circumstances favouring their existence in the Tertiary period, ii. 53

O

Ocean, force exerted in the creation of the, i. 31

Octoblepharum albidum, leaves of, i. 330

Octopods, structure of, ii. 245

Octopus vulgaris, or poulpe, structure of, ii. 245-247

Odonthalia, structure of, i. 242

Œdogonium capillare, reproduction of, i. 216

Oïdium, structure and habitat of, i. 290

Oïdium Tuckeri, or vine mildew, fungus producing, i. 295

297Oils, dead, manufacture of, i. 120 essential, chemical combinations forming, i. 97 vegetable, i. 422 formation of fixed and essential, artificially, i. 424

Oleandra, characters of the genus, i. 347

Oleandra neriiformis, structure of, i. 347

Olefiant gas, absorptive power of, i. 39, 40, 41 amount of absorptive power, i. 41 great absorption of, i. 47 formation of, i. 97 amount of carbon in, i. 105 one of the illuminants in coal gas, i. 118 chemical composition of, i. 128

Olefiant oil, i. 104

Olive oil, i. 422

Onion, structure and mode of reproduction of, i. 388

Oniscus, common wood-louse or slater, structure of the, ii. 202

Onoclea, characters of the genus, i. 348

Onoclea sensibilis, characters and habitat of, i. 348

Oolina claxata, shell of, ii. 48

Opacity in liquids and solids synonymous with accord, i. 37 causes of opacity, i. 37

Operculina, structure of, ii. 38, 46 an instance of an individual combined with a common life, ii. 38.

Ophioglossaceæ, characters of the group, i. 365

Ophioglossum, characters of the genus, i. 365

Ophioglossum vulgatum, structure and habitat of, i. 365

Ophionyx, structure of, ii. 173

Ophiuridæ, or snake stars, structure of, ii. 172, 173 power of reproducing rays, ii. 173

Ophrys apifera, or bee ophrys, structure and mode of reproduction of, i. 397

Ophrys, fly, structure and mode of reproduction of, i. 396

Opium, alkaloids obtained from, i. 427 almost universal use of, in the East, i. 427

Orange, amount of radiant heat absorbed by the perfume of, i. 44 fructification of the, i. 381

Oranges, fungus of decayed, i. 290

Orbitolite, characters of the, ii. 33 a fossil gigantic one found in Canada, ii. 54

Orbitolites complanatus, structure of, ii. 33, 34 298development and varieties of, ii. 35, 36 habitat of, ii. 36

Orchids, their structure, habitat, and mode of reproduction, i. 388-403 theoretical structure of, i. 403

Orchil, whence obtained, i. 303 from what obtained, i. 124

Orchis mascula, structure and mode of reproduction of, i. 389, et seq.

Orchis pyramidalis, structure and mode of reproduction of, i. 393, et seq.

Oscillatoria littoralis, structure and motions of, i. 213

Oscillatoria spiralis, motions of, i. 213

Oscillatoriæ, structure, habitat, and motions of, i. 213 reproduction of, i. 214

Osmunda regalis, structure and habitat of, i. 363

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

Ostrapods, characters of the, ii. 207

Otolites of Gastropoda, ii. 236

Otolites of Thaumantias, ii. 93

Ovulata, siliceous skeleton of, ii. 60

Oxalic acid, former and present modes of making, i. 116 produced by lichens, i. 303 synthetical formation of, i. 424

Oxygen, i. 6-11 effect of the combination of the atoms of oxygen and carbon in combustion, i. 30 absorptive power of ozonized oxygen, i. 43 absorptive power of, i. 39, 41 proportion of oxygen to hydrogen in the composition of water, i. 94 limit to the number of combustions of, with nitrogen, i. 95 weight of the atoms of, in the peroxide of manganese, i. 99 weight of the atoms of, compared with those of hydrogen, i. 99, 100 spectrum analysis of, i. 139 inhalation and exhalation of, by plants, i. 416, 417

Oysters, iodine found in, i. 19

Ozone, i. 7 effect of the combination of ozone and oxygen in the absorption of radiant heat, i. 43 Prof. Tyndall’s conjecture as to the production of ozone, i. 44 its affinity for iodine, i. 96 its possible effect on the solar spectrum, i. 132 production of, i. 17

299P

Padina Pavonia, or Peacock’s tail laver, structure of, i. 247

Pagurus, or hermit crab, structure and mode of reproduction of, ii. 197

Palm, stem or axis of a, i. 384 growth and reproduction of palms, i. 384, 385

Palmoglœa macrococca, structure and development of, i. 182

Palmyra palm, growth of the stem of, i. 385

Pandanus or screw pine, roots and habitat of, i. 387

Papillaris, siliceous skeleton of, ii. 60

Paraffin, i. 105 crystals of, how produced, i. 127

Paraffin oil and candles, i. 119, 127

Paramœcium caudatum, cilia and mouth of, ii. 68, 69 immense propagation of, ii. 74

Parkeriaceæ, or Ceratopteridineæ, structure and habitat of, i. 363

Parmelia saxatilis, structure and habitat of, i. 305

Parmeliacei, structure of the, i. 302 characters of the group, i. 304

Parmelia parcolerina, yellow dye obtained from the, i. 124

Parmelia parietina, dye obtained from, i. 303

Passalus cornutus, parasitic fungus in the stomach of, i. 274

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

Patellidæ, or limpets, structure, food, and habitat of, ii. 238, 239

Paulia perforata, organs of reproduction of, i. 301

Pea mildew, fungus producing the, i. 295

Peach, cause of blistered leaves of the, i. 291

Pear, cause of blistered leaves of the, i. 291

Pearl oyster, nacreous lining of shell of, ii. 234

Pease, caseine obtained from, i. 125

Peat, and peat mosses, i. 333

Pecten, or scallop, eyes of the, ii. 235

Pediastrum, structure and development of, i. 194

Pedicellaria globosa, structure of, ii. 180

Pelagia, structure and mode of reproduction of, ii. 97

Peltigeri, characters of the group, i. 305

Peneroplis, structure of, ii. 31, 32

Penicillia mould, structure of the, i. 285

Penicillium armeniacum, spores of, i. 285, 286

Penicillium candidum, production of, i. 287

Penicillium glaucum, structure and habitat of, i. 286, 287 300its polymorphous character, i. 287 in the yeast of beer, i. 288 its production of acetic fermentation, i. 288

Pennatula phosphorea, structure and habitat of, ii. 128 modes of reproduction of, ii. 129

Pennatulidæ, or sea-pens, structure, habitat, and mode of reproduction of, ii. 128, 129

Pentacrinites, structure of, ii. 175

Pentacrinus caput-Medusæ, structure and habitat of, ii. 175

Pentacrinus Europæus, structure of, and change to a comatula, ii. 176

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

Peranemeæ, or Woodsieæ, characters of the group, i. 350

Perfumes of flowers and plants, absorption of radiant heat by the, i. 44 weight of the perfumes, i. 45 chemical combinations forming, i. 97

Peridinium, structure and habitat of, ii. 72 scarlet colour it gives to the sea, ii. 72, 75 mode of propagation of, ii. 75

Perisporacei, structure and habitat of, i. 295

Periwinkle, tongue of, ii. 239

Peronospora infestans, its destruction of the potato, i. 284 structure and mode of working, i. 284, 285 its effects on the branches and wood of trees, i. 285

Perophora Listeri, structure, habitat, and development of, ii. 222, 223 larva of, ii. 224

Petroleum, enormous quantities of, in North America, i. 126 the Babylonian petroleum fountains of Is, i. 126 geological formation in which it occurs, i. 126 dangers of petroleum wells, i. 127 substances yielded by it on destructive distillation, i. 127

Peyssonnelia, habitat of, i. 237

Peziza aurantia, cells of staff-shaped particles of, i. 291

Peziza elegans, beauty and habitat of, i. 291

Peziza vesiculosa, force of its ejection of its sporidia, i. 292

Pezizæ, structure and habitat of the genus, i. 290, 291 fructification of, i. 291 eel-shaped particles or antherozoids of, i. 292 force with which many of them eject their sporidia, i. 292

Phacopsis, organs of reproduction of, i. 307

Phalloidei, structure of, i. 268

Phallus Mokusin, a food of the Chinese, i. 268

Phascei, characters of, i. 329

301Phenic acid, i. 123

Phenyle, chemical composition of, i. 128

Philomedusa Vogtii, a parasite of the medusæ, ii. 100

Phonolite stone, on the Rhine, of what it consists, i. 206

Phosphorescence, property of, i. 66 of insects, fish, and plants, i. 67 of inorganic substances, i. 67 essential difference between phosphorescence and fluorescence, i. 67, 68

Phosphorescent light of luminous fungi, i. 264 causes of this, i. 264

Phosphorus, i. 17 whence procured, i. 17 red allotropic, i. 17 takes fire spontaneously in chlorine gas, i. 19 atomic weight of, compared with that of hydrogen, i. 100

Photography, importance of the magnesium light in, i. 154

Phyllodoce, structure of, ii. 157

Phyllopoda, characters of the order, ii. 209

Physalia, or ‘Spanish man-of-war,’ structure, and modes of locomotion and reproduction of, ii. 111-114

Physaliidæ, characters of the order, ii. 111

Physomycetes, characters of the order, i. 296

Physophora hydrostatica, structure and habitat of, ii. 109, 110

Physophoridæ, characters of the family of the, ii. 109-111

Pillwort, structure and habitat of, i. 371, 372

Pilularia globulifera, or pillwort, structure and habitat of, i. 371

Pilularia minuta, structure of, i. 371

Pinna, structure of the shell of, ii. 233

Pitch, manufacture of, i. 120

Planets, spectra of the, i. 157, 158, 161, 162

Plants, absorption of radiant heat by the perfumes of, i. 44 weight of the perfumes, i. 45 phosphorescence of, i. 67 their synthetic process of rearing their fabrics, i. 96 this process imitated by artificial means, i. 96 chemical nature of the colouring matter of, i. 428, 429

Platinum, properties of, i. 5 how vaporized, i. 30 effect of electricity on, i. 32 crystals of, formed artificially by electricity, i. 74 its resistance to electricity, i. 90

302Pleurocarpi, characters and habitat of the group, i. 328

Pleurosigma angulatum, structure of, i. 198, 199

Plumbago, or natural graphite, little or no porosity of, i. 112

Podocyrtis Schomburgi, structure and habitat of, ii. 20, 21 fossil and existing species of, ii. 20

Poisons, vegetable, i. 425, 426

Polarization of light and heat, i. 68, 69 relation of polarization of light and heat to crystallization, i. 70, 71

Pollen of flowering plants, i. 379

Polyatomic theory, the, i. 107

Polycystina, structure and habitat of the, ii. 19, 20

Polygastria, a name for the Infusoria, ii. 71

Polyides rotundus, mode of reproduction of, i. 229 structure and mode of propagation of, i. 237, 238

Polynoë, structure of, ii. 160

Polypary of the Alcyon zoophytes, ii. 123

Polypes. See Hydrozoa

Polypodiaceæ, characters of the order, i. 344 sporangia of, i. 343

Polypodineæ, characters of the group, i. 344 habitat of the, i. 345

Polypodium, structure and habitat of the genus, i. 345 vulgare, fronds of, i. 340, 345 sori of, i. 342, 345 structure of, i. 345

Polyporei, structure, habitat, and growth of, i. 264, 265

Polysiphonia, structure of the genus, i. 233

Polysiphonia elongata, structure and mode of propagation of, i. 234

Polystichum, characters of the genus, i. 347 sorus and indusium of, i. 347

Polystichum aculeatum, characters of, i. 348

Polystichum angulare, characters of, i. 348

Polystichum Lonchitis, structure of, i. 347

Polystichum proliferum, organs of reproduction of, i. 348

Polystomella, characters of the genus, ii. 47

Polystomella crispa, form of, ii. 28 structure and habitat of, ii. 47, 48 cristata, form of, ii. 28 striato-punctata, habitat of the, ii. 48

Polytrichei, characters of the tribe, i. 329

Polytrichum commune, organs of fructification of, i. 325

Polytrichum dendroides, structure of, i. 329

303Polyzoa, or Bryozoa, characters of, ii. 218

Polyzonia cuneifolia, structure of, i. 242, 243

Porites, or reef-building corals, ii. 140

Porphyra laciniata, structure and habitat of, i. 227

Porphyra vulgaris, structure, habitat, and mode of reproduction of, i. 227

Porpita, characters of the genus, ii. 117 glandifera, structure, habitat, and mode of reproduction of, ii. 117, 118

Potash, caustic, effect of the heating of, by an electric discharge, i. 84 its effect on electricity in a vacuum tube, i. 86 cyanate of, combination forming, i. 106 nitrate of, its opacity to the invisible rays, i. 65 oxalate of, formation of, i. 117 violet coloured light obtained by the combustion of, i. 133 in the land plants, i. 414

Potassium, i. 3 affinity for oxygen, i. 96 atomic weight of, compared with that of hydrogen, i. 100 one of an isomeric triad with cæsium and rubidium, i. 105 iodide of, whence obtained, i. 19

Potato, fungi causing the murrain in the, i. 284, 285 mode in which the injury is done, i. 284 poisonous nature of the leaves and berries of the, i. 426, 427

Poulpe, structure of the, ii. 245

Praya diphys, structure and mode of reproduction of, ii. 103-106

Propagation of diatoms by bisection, by conjugation, and by gonidia, i. 200

Protein produced by plants, i. 419

Protococcus pluvialis, structure and development of, i. 184 cycles of reproduction, i. 186

Protococcus viridis, abundance of, found in dust from Egypt, ii. 65

Protophytes, structure and development of, i. 182

Protoplasm of plants, structure and function of, i. 412, 413

Protozoa, structure of the, ii. 13

Pterideæ, characters of the group, i. 357

Pteris, characters of the genus, i. 357

Pteris aquilina, stems of, i. 339 or bracken, structure, mode of reproduction, and habitat of, i. 357, 358

Pteris esculenta of New Zealand, i. 358

Pteris serrulata, development of spores of, i. 337 antheridium and spermatozoids of, i. 338

304Pteris serrulata: archegonium of, i. 338

Pucciniæ, structure and habitat of the sub-order, i. 276, 277

Puccinia Amorphæ, spores of, i. 276

Puccinia Fabæ, structure, habitat, and method of reproduction of, i. 280 alternation of generations of, i. 280

Puccinia Graminis, spore-cases of, i. 280

Puccinia lateripes, spores of, i. 276

Puff-balls of the meadows, i. 267

Purple dyes, i. 123, 124

Pycnogonoïdea, or spider crabs, structure and habitat of, ii. 211

Pyrosomidæ, structure and mode of reproduction of the, ii. 225

Pyxinei, characters of the, i. 307

Q

Quartz, rock-crystal the purest form of, i. 17 certain thickness of, not transparent to invisible rays of light, i. 65 axis of symmetry of, i. 72 aqueous solution of, i. 110 characteristics of the, i. 111

Queen conch, shell of, ii. 234

Quinine, structure of, and whence obtained, i. 427

Quinqueloculina Bronniana, form of, ii. 228

R

Radiation of light and heat, i. 34, 35 effects of, i. 35, 36 generally independent of colour, i. 36 Professor Tyndall’s experiments, i. 38 experiments showing radiation to be equal to absorption, i. 46 dynamic radiation, i. 49 absorption a phenomenon irrespective of aggregation, i. 53

Radicles, compound, i. 106

Ramalina calicaris, gluten of, i. 303

Ramalina polymorphum, dyes obtained from, i. 303

Ramalina scopulorum, dyes of, i. 303

Raphides, structure and formation of, i. 424, 425

Red Sea, foraminifera in the, ii. 51

305Reed, Cordyceps on the ergot of the, i. 293

Reed, Italian, vegetable tissues represented in, i. 175, 176

Reef-building corals, ii. 138-142

Reefs, barrier, formation of, ii. 143

Resins, formation of, i. 422

Respiration, chemical powers causing, ii. 4

Respiration of the muscles, ii. 8

Reticularia, characters of the order, ii. 24

Reticularia maxima of cucumber beds, i. 269

Rhabdonia Coulteri, mode of propagation of, i. 236

Rhamnus cathartica, M. Charwin’s discovery of a green dye obtained from the, i. 124

Rhizocrinus Lofotensis, structure of, ii. 175

Rhizopoda, structure of the, ii. 13 simple Rhizopods, forms of, ii. 22

Rhizoselenia, enormous masses of, in the Indian Ocean, i. 205

Rhizospermæ. See Marsileaceæ

Rhizostoma, or many-mouthed medusæ, structure and mode of reproduction of, ii. 97, 98 food of, ii. 98

Rhodomelaceæ, structure &c. of, i. 241

Rhodospermeæ, characters of the, i. 180 structure and mode of reproduction of, i. 227, et seq. causes which affect the form and limits of, i. 243

Rhodymenia palmata, structure and mode of reproduction of, i. 236

Rhodymeniaceæ, structure of, i. 236

Ricciaceæ, or Crystalworts, characters of the order, i. 316

Richmond, in Virginia, siliceous deposit upon which it stands, i. 206

Riella, characters of the genus, i. 316, 317

Rivularia, structure of the genus, i. 213, 215

Rivularia nitida, structure and motions of, i. 213, 215

Rocella fuciformis, dye and orchil obtained from, i. 303

Rocella tinctoria and fusiformis, blue and purple dyes obtained from, 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

306Rosaniline, 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

307Salt: 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

308Sea-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

309Smut 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