None
powerful microscope. That the platinum is not in a state of true solution, is shown by the fact that it does not lower the freezing-point or vapor-tension of the solvent. Such solutions, which have been prepared not only of platinum, but of gold, silver, cadmium, iridium, etc., have been studied extensively by Bredig, especially in the cases of platinum, gold, and silver. These pseudosolutions of the heavy metals have been found to have some remarkable properties in connection with their catalytic action, especially as effecting the decomposition of hydrogen dioxide. Analogies between the action of these solutions and organic enzymes have been pointed out and established experi- mentally, which are undoubtedly deep-seated. Without going into detail in this subject, it may be said that infinitesimal quantities of the same substances which poison the organic enzymes, also "poison" the colloidal solutions of the metals, preventing or greatly hindering 496 PRINCIPLES OF INORGANIC CHEMISTRY their catalytic activity. A number of other analogies have been shown to exist. Oxides and Hydroxides of Platinnm. — Platinum forms two oxides, PtO and PtOj, which are derived from the corresponding hydroxides, Pt(OH), and Pt(0H)4, by careful heating. The hydroxides are ob- tained from the platinous and platinic chlorides, or from the double chlorides with the alkalies, by the action of a base. All of these substances are unstable at elevated temperatures, breaJkiug down and yielding metallic platinum. Chlorides of Platinum. — Platinum forms two chlorides — platinous chloride, PtClj, in which the platinum is bivalent, Pt, and platinic ++++ chloride, in which the platinum is tetravalent, Pt. Platinous chloride is obtained by heating platinum sponge to 250° in chlorine gas. It is a green powder which is insoluble in water. When treated with hydrochloric acid it dissolves forming hydro- chlorplatinous acid, HjPtCl^. When this compound is heated to 300* it breaks down into hydrochloric acid and platinous chloride. This acid is also produced by reducing hydrochlorplatinic acid, HjPtCl^ the latter losing two atoms of chlorine and passing over into the former. Salts of hydrochlorplatinous acid are known. These have the composition M2PtCl4. The chlorplatinous ion PtCl4 is, there- fore, bivalent. Platinic chloride, PtCl4, is obtained by carefully heating hydro- chlorplatinic acid to 350° in the presence of chlorine. It is not obtained by dissolving platinum in aqua regia, Platinic chloride, which is quite soluble in water, readily combines with hydrochloric acid forming hydrocMorplatinic acid, HgPtClg. This same com- pound is formed when platinum is dissolved in aqua regia. Many salts of this acid are known. We have already seen that the potassium and ammonium chlorplatinates, K,PtCl« and (NH4)2PtCl6, are difficultly soluble in water, while the sodium salt, NajPtClfl, is readily soluble. This reagent thus enables us to sepa- rate sodium from potassium. It is also very important in connection with the quantitative determination of potassium, since potassium chlorplatinate is almost completely insoluble in a mixture of water and alcohol. The calcium and rubidium salts of this acid are even less soluble than the potassium and ammonium compounds. In this acid the chlorplatinic ion, PtClg, is bivalent, and this is another example of a metal forming part of an anion. When a solution of this acid is electrolyzed the platinum passes to the anode and not to the cathode. We have met with a number of similar cases. PLATINUM 497 Platinum in the bivalent condition forms a double nitrite with the alkaline nitrites, which is analogous in composition to the alkali platinous chlorides. Thus, when potassium platinous chloride is allowed to remain in contact for a time with potassium nitrite, the following reaction takes place : — KjPtCl^ + 4 KNOa = KsPtCNOs)^ + 4 KCl. The compound K2Pt(N02)4 is known as potassium platinonitrite. Sulphides of Platiniim. — Platinum forms the two sulphides, PtS and PtSj, as we would expect. These are obtained by precipitating platinous and platinic solutions by means of hydrogen sulphide. When heated these compounds lose sulphur, and metallic platinum is formed. Double Cyanides of Platinum. — Platinum forms a number of double cyanides, which are characterized by their unusually beau- tiful color and fluorescence. They can all be regarded as compounds of platinous cyanide, Pt(CN)2, with the cyanide of the element in question. The acid of which these substances are salts, H2Pt(CN)4, can be obtained by treating the barium salt with sulphuric acid. The potassium salt, K2Pt(CN)4.3H20 is formed by adding platinous chloride to potassium cyanide. Two compounds which are characterized by their unusual beauty are the double cyanides of barium and magnesium. Bariimi plati- nous cyanide, BaPt(CN)4.4H20, is formed by passing hydrocyanic acid into water containing a mixture of barium carbonate and platinous chloride. It is light yellow in color, with a beautiful play of greenish-violet light over the surface as the crystals are turned. This compound which converts ultra-violet radiation into visible light, and is, therefore, fluorescent, has come into prominence recently in connection with the study of Kdntgen rays. It trans- forms these, and also the radiation given off by uranium, into visible radiations, and has been used in the preparation of screens upon which Rontgen rays are allowed to fall that their presence might be detected by the eye. The magnesium platinous cyanide, MgPt(CN)4, is remarkable for its color. It can be formed by treating an aqueous solution of the barium salt with a solution of magnesium sulphate. It crystallizes in red prisms. It has a bright green lustre, so that when the sides are observed in reflected light they appear green, while the ends are blue. It is questionable whether another compound of equal beauty is known in the whole field of chemistry. 2k INDEX AbM Nollet, demonstration of osmotic pressure, 100. Absolute boiling-point of a gas, 284. Absolute zero, can it be realized experi- mentally ?, 44. Absolute zero of temperature, determi- nation of, 26. Absorption of certain constituents from the soil by plants, 303. Accumulator, 483. Accumulators, 193. Acetylene, effect on luminosity of flames, 203. Acetylene hydrocarbons, 278. Acetylene light, 296. Acid and basic properties, 144. Acid, definition of, 124. Acid dibasic, 212. Acidic indicator, 213. Acid means hydrogen ions, 124. Acid, monobasic, 212. Acid salts, 216. Acids, halogen, comparison of the, 169. Acids, hydrogen present in all, 40. Acids, neutralization of by bases, 210, 217. Acid sodium carbonates, 327. Acid sodium sulphate, 325. Acids of silicon, 300. Acids, organic, 288. Acid sulphides, .181. Acids, weak, neutralization with weak bases, 219. Acid, tribasic, 212. Agate, 300. Air, 235. Air, a mixture or compound, 237. Air, liquid, 238. Air, physical properties of, 237. Ahr-slaked lime, 365. Alba, magnesia, 386. Albite, 414. Alcohols, 284. Aldehydes, 287. Alkali metals, characteristics of, 361. Alkaline earths, detection of, 381. Alkaline earths, relations between, 38L Allotropic forms of carbon, 272. AUotropic modification of oxygen, 29. Allotropy, 29. Alloys, 314, 476. Alloys of aluminium, 408. Alloys of manganese, 436. Alloys of silver, 469. Alum, burnt, 413. Aluminate of sodium, 410. Aluminates, 410. Aluminite, 413. Aluminium, alloys of, 408. Aluminium amalgam, 409. Aluminium bronze, 408, 462. Aluminium carbide and carbonate, 414. Aluminium chloride, 411. Aluminium, detection of, 416. Aluminium fluoride, cryolite, 412. Aluminium, occurrence and prepara- tion, 407. Aluminium oxide and hydroxide, 409. Aluminium, properties of, 408. Aluminium silicates, 414. Aluminium silicates, applications of, 415. Aluminium sulphate, 412. Aluminium sulphide, 412. Alums, 333, 413. Alums, chromium, 449. Amalgamation process, 467, 475. Amalgams, 207, 388, 399, 409, 485. Amblygonite, 352. Amethyst, 300. 499 500 INDEX Amethyst, oriental, 400. Ammonia, 202. Ammonia, action of on cobalt salts, 433. Ammonia, action of on mercury salts, 405. Ammonia, chemical properties of, 203. Ammonia, composition of, 204. Ammoniac, sal, 203. Ammonia liquid, high specific heat of, 206. Ammonia, or Solvay process of pre- paring ammonium carbonate, 327. Ammonia, physical properties of, 205. Ammonium, 204, 207. Ammonium acid carbonate, 360. Ammonium amalgam, 207. Ammonium carbonate, 360. Ammonium chloride, 356. Ammonium chloride dissociated by heat, 367. Ammonium chloride, dissociation by heat diminished by an excess of either product of dissociation, 357. Ammonium chloride, dry, dissociation of by heat, 367. Ammonium hydrazoate, or triazoate, 358. Ammonium hydrosulphide, 369. Ammonium hydroxide, 221, 365. Ammonium hydroxide, dissociation of, 206,222. Ammonium hydroxide, measurement of the dissociation of, 222. Ammonium ion, characteristic reaction . of, 362. Ammonium, salts of, 368-360. Ammonium sodium phosphate, 329. Amorphous forms of carbon, 273. Amphoteric reaction, 328. Analogues, atomic, 148. Andrews, discovered critical tempera- ture and pressure, 27. Andrews, on critical constants, 284. Anglesite, 482. Anhydrite, 129, 368. Anion, 64, 111. Annealed glass, 375. Anode, 50. "Antichlor," 194,326. Antimonic acid, 264. Antimonic acid, meta-, 204. Antimonic acid, pyro-, 264. Antimonious acid, sulph-, 266. Antimonite, metasulph-, 266. Antimony, acids of, 264. Antimony butter, 266. Antimony, compounds with hydrogen and oxygen, 262. Antimony, compounds with the halo- gens, 264, 265. Antimonyl group, 263. Antimony, occurrence and prepazatioD, 261. Antimony, oxides of, 262. Antimony, properties of, 261. Antimony, sulphides of, 265. Apatite, 242, 372. Aqua regia, 232. Aragonite, 369. Arbor Saturnl, 479. Argentan, 462. Argentite, 467. Argon, 239. Argon, number of atoD:i8 in the mole- cule of, 239, Argyrodite, 306. Arrhenius, work on the origin of the theory of electrolytic dissociation, 109. Arsenate, sulphometa-, 260. Arsenic acids, 268. Arsenic, compounds with halogens, 258. Arsenic, compounds with hydrogen and oxygen, 256. Arsenic, compounds with sulphur, 259. Arsenic, occurrence and preparation, 265. Arsenic, properties of, 255. Arsenic pyrites, 255. , Arsenic acid, sulph- or thlo-, 200. Arsenic, sulpho-salts of, 259. Arsenic, white, 257. Arsenious acid, 267. Arsenious acid, sulph- or thio-, 260. Arsine, 256. Artificial preparation of ice, 206. Asbestos, 384. Atmosphere, composition of the, 235. INDEX 601 Atmospheric air, 235. Atmospheric air and rare elements oc- curring in it, 235. Atomic analogues, 148. Atomic theory, 12. Atomic volumes, 14.5. Atomic volumes, curve of, 146. Atomic weights and chemical proper- ties, 142. Atomic weights and combining num- bers, 69. Atomic weights and physical proper- ties, 145. Atomic weights corrected by the Peri- odic System, 147. Atomic weights, determination of, 60. Atomic weights from molecular weights, • 73. Atomic weights from specific heats, 75. Atomic weights, isomorphism an aid in determining, 77. Atomic weights, most accurate method of determining, 79. Atomic weights of the elements, table of, 81. Aurates, 477. Available phosphoric acid, 374. Avogadro's hypothesis, 71. Avogadro^s hypothesis and molecular weights, 72. Avogadro's law, apparent exceptions to, 87. Avogadro^s law applied to the osmotic pressure of solutions, 106. Avogadro's law, explanation of appar- ent exceptions to, 88. Azurite, 460, 465. Baeyer prepares permonosulphoric acid, 195. Banca tin, 484. Barite, 378. Barium chromate, 449. Barium, detection of, 381. Barium dioxide, 378. Barium dioxide used in preparing oxy- gen, 16. Barium hydroxide, 379. Barium, occurrence, 378. Barium, other insoluble compounds ol. 381. Barium, oxides of, 378. Barium platinocyanide, 497. Barium, salts of, 379-381. Barium sulphate transformed into ba- rium carbonate, 380. Baryta water, 879. Base, diacid, 211. Base-forming elements, 361. Base, monacid, 211. Bases are hydroxy I compounds, 210. Bases, neutralization of by acids, 210, 217. Bases weak, neutralization with weak acids, 219. Base, triacid, 211. Basic and acid properties, 144. Basic indicators, 215. Basic lining in Thomas-Gilchrist con- verter, 422. Basic salts, 216. Batteries, use of zinc in, 391. Bauxite, 305, 407, 409. Beckmann, boiling-point apparatus, 97. Beckmann, freezing-point apparatus, 94. Beckmann thermometer, 96. Becquerel rays, 457. Bell metal, 462. Benzene hydrocarbons, 278. Berlin blue, 427. Berthollet, on law of constant propor- tion, 9. Beryl, 383. Bessemer converter, 422. Bessemer steel, 422. Binary electrolyte, 112. Bismuth chloride, 268. Bismuth hydroxide, 268. Bismuth, occurrence and properties, 267. Bismuth, oxides of, 268. Bismuth sulphide, 268. Bismuthyl group, 268. Bivalent, 134. Blanc, I^, method of preparing sodium carbonate, 326. Bleaching-powder, 866. 602 INDEX Bleaching-powder used in making chlo- rine, 116. Block-tin, 484. Blowing of glass, 376. Blowpipe, 293. Blowpipe, oxyhydrogen, 87. Blue vitriol, 464. Bog-iron ore, 410. Boiling-point, absolute, of a gas, 284. Boiling-point apparatus of Beckmann, 06. Boiling-point apparatus of Jones, 08. Boiling-point method of determining molecular weights, 05. Bone-ash, 372. Bone-black, 274. Boracite, 307. Borax, 307, 330. Borax bead, 330. Borax octohedral, 330. Borax, prismatic, 330. Boric acids, 308. Borocalcite, 307. Boron, 307. Boron, compounds with the halogens, 309. Boron nitride, 308. Boron, occurrence, preparation and properties, 307. Boron, specific heat varies with the temperature, 307. Boron trioxide, 308. _ Boyle and Gay-Lussac, combined ex- pression of the laws of, 26. Boyle's law for gases, 24. Boyle's law for osmotic pressure, 105. Brass, 388, 462. Brauner's Periodic System, 141. Braunite, 436. Brick or fire-brick, 415. Brimstone, crude, 171. Britannia metal, 485. Bromic acid, 157. Bromine, 152. Bromine atoms and bromine ions, 154. Bromine, chemical properties of, 153. Bromine, compound of with chlorine, 158. Bromine, compound with iodine, 165. Bromine, compounds with oxygen and hydrogen, 157. Bromine, detection of, 153. Bromine, occurrence and preparation, 152. Bromine, physical properties of, 154. Bromine water, 164. Bromoform, silicon, 303. Bronzes, 408, 436, 462, 485. Bunsen and Kirchhofif, discovery of rubidium, 354. Bunsen and Kirchhoft^s law of light absorption, 45. Bunsen burner, 293. Bunsen, method of determining densi- ties of gases, 87. Bunsen photometer, 297. Burning in oxygen, explanation of, 18. Burnt alum, 413. Caesium, occurrence, compounds, 355. Cadmium, 396. Cadmium molecule consists of one atom, 397. Cadmium, salts of, 307. Cailletet, liquefaction of oxygen, 27. Calamine, 387. Calcite, 368. Calcium acid carbonate, 371. Calcium carbide, 368. Calcium carbonate, 368. Calcium ca,rbouate, decomposition curves, 370. Calcium carbonate, primary, 391. Calcium, compounds with the halogens, 305. Calcium, detection of, 876. Calcium hydride, 363. Calcium hydroxide, 364. Calcium hypochlorite, 129, 366. Calcium manganite, 438. Calcium, occurrence, preparation, and properties, 353. Calcium oxalate, 375. Calcium oxide, 363. Calcium phosphates, 372. Calcium silicate, 374. Calcium sulphate, 367. Calcium sulphides, 307. INDEX 503 Calomel, 401. Calorie, 22. Calorimelerf 22. Candle, 291. Carats, 476. Carbamate of ammoniam, 860. Carbide of calcium, 368. Carbides, 2^. Carbon, allotropic forms of, 272. Carbon, amorphous forms of, 273. Carbonates, formed from silicates, 302. Carbonates, hydrolyzed by water, 282, 328. Carbon bums in oxygen, 17. Carbon, compounds with halogens, 288. Carbon, compounds with hydrogen, 277. Carbon, compound with silicon, — car- borundum, 304. Carbon, different forms contain dif- ferent amounts of energy, 275. Carbon dioxide, 2HO-283. Carbon dbxHe reriuced by plants, 282. Carbon dlsiulphMe, 289. Carbonic acid, thio-, 280. Carbonic acid, trithio-, 280. Carbon monoxide, 278. Carbon monoxide, thermochemistry of, 279. Carbon, r61e of, in producing light, 291. Carbon, specific heat of, 276. Carbon subpjcide, 287. Carbon tetrnchlortde, 288. Carbonyl compounds, 429. Carbonyl, nickel, 434. Carborundum v?04, Camallite, 1 10, 333, 337, 354, 384. Carols liquid 105. Carr^ ice machines^ 206. Casfiiterite, 484. CflflsiiK^ purple of, 476. Cast-iron, gray, white, 421. Catalytic decomposition of hydrogen dioxide, 67. Catalytic reactions and catalyzers, 36, 187. Cathode, 50. Cation, 64, 111. Caustic, lunar, 473. Caustic potash, 336. Cavendish discovered hydrogen, 33. Celestite, 376, 377. Cells, storage, 193. Cement, 416. Cement, hydraulic, 370. Cement, Portland, 370. Cements, hydraulic, 410. Cerite, 417. Cerium, compounds of, 300. Cenjssite, 478, 482. Cbal copy rile, 460. Chalcosite, 460. Chalk, 363, 369. Chamber acid, 189. Chamber crystals, 234. Chamber, leaden, 188. Chameleon, mineral, 441. Charcoal, 273. Chemical action at a distance, 425. Chemical combination, 6. Chemical elements, 4. Chemical equation, 6. Chemical properties and atomic weights, 142. Chemical reactions reversible, 179. Chemistry and Physics, relations be- tween, 1. Chemistry, science of, 7. Chili saltpetre, 158, 312. China silver, 462. Chloramide, mercurous, 406. Chlorates, 131. Chlorates, ion of chlorine, and the ion of, 131. Chlorctiromic acid, 451. Chlor-ekctrolytie gas, 121. Chloric acid, 130. Chlori nation process, 475. Chlorine, 115. Chlorine a bleaching agent, 118. Chlorine, action on hydrogen, 118. Chlorine, action on organic compounds, 118. Chlorine, action on water, 118. Chlorine a diisinfectant, 118. Chlorine and hydrogen, volume rela- tions in which they combine, 121. Chlorine, an element or compound, 115. Chlorine, a strong oxidizing agent, 118. 504 INDEX Chlorine, chemical properties of, 117. Chlorine, combuBtion in, 117. Chlorine, coinpooud of with bromine, 158. Chlorine, compounds with iodine, 105. Chlorine, compounds with oxygen and hydrogen, 128. Chlorine, compounds with sulphur, 105. Chlorine litiipniitm;^ ^ii», 121. Chlorine dioxide^ 33. Chlorine, dry inactJvtiy of, 121. Chlorine, electrolytic method of pre- paring, 117. Chlorine hydrate, 110. Chlorine ion and the ion of chlorates, 131. Chlorine, liquefaction of, 120. Chlorine, occurrence and preparation, 115. Chlorine, power of to combine with oxygen, 128. Chlorine, prepared by methods of Deacon and VVeldon, 116. Chlorine wattr 118. Chloroform, ailipoiij 303. Chlorous acid, 133. Cblort%alphuric acid, 196. Chromateii, Aiih Chrome orange, 483. Chrome yellow, 450, 483. Chromic acid, 44(5, 449. Chromic acid, chlor-, 451. Chromic acid, chlorides of, 451. Chromic acid, Morse's method of pre- paring, 449. Chromic acid, per-, 451. Chromic chloride, 448. Chromic salts, 447. Chromites, 445, 449. Chromium, 445. Chromium alums, 449. Chromium, detection of, 452. Chromium, hydroxides of, 446. Chromium ions, valence and properties of, 446. Chromium, oxides of, 445. Chromium, pt?riodical or rhythmic solu- tion in acids, 445. Chromous salts, 447. Chiomyl chloride, 451. Chrjsoberjl, .^-^ :. 410. Cmnabar, 7], 308, 404. Citmte soluble pho6{^iate, 373. Clark element, 406. Claosius's electro-chemical Uieory, llOl aay, 407, 414. Coal-gas, 202. Coal or stone-coal, 276. Cobalt, 431. Cobalt bead, 432. Cobalt cyanides, 432. Cobalt, double nitrite of, 433- Cobaltic compounds, 431. Cobaltite, 431. CobiikitetJ, 432. Cobaltous compounds, 431. Cobaltous salts, 432. Cobalt, oxides and hydroxides, 431. Cobalt salts, action of ammonia on, 433. Coins, 462. Coke, 274. Colloidal silver, 468. Colloidal solution, 424. Colloidal solution of gold, 476. Colloidal solution of platinum, 496. Colloidal solution of tungstic acid, 466. Colloids, 301. Color, change in, with change in elec- trical charge, 420. Color of pentianganates, 443. Columbium, 270. Combination, chemical, 6. Combining numbers and atomic weights, 69. Combining numberi, chemical methods of dutenjiining» 00. Combining weights, law of, 11. Combustionn 18. CombnsrJnn in diloHne, 117. Combustion, increase of weight in, 19. Combustion, measurement of the beat of, 21. Combustion, oxygen used up in, 20. Combustion, phlogiston theory of, 18. Commercial fertilizer, 373. Commercial phosphate, analysis of, 873. INDEX 605 Compoflition changed in chemical re- action, 2. Composition of the earth, 6. Compoeition of water, 60. Compounds and elements, 8. Compounds with oxygen, names of, 23. Concentration element, 304. Condensation of steam, heat of, and of solidification of water, 56. Conductivities, Kohlrausch method of measuring, 112. Conductivities, molecular, 112. Conductivity measurements, dissocia- tion calculated from, 114. Conductivity method, 112. Conductivity of water, 63. Conservation and correlation of energy, 13. Conservation of energy, importance of for the science of chemistry, 13. Conservation of mass, law of, 8. Constant proportion, law of, 0. Continuity of passage from liquid to gas, 285. Cooling, effect of on flame, 295. Copper acetylene, 465. Copper, alloys of, 462. Copper ferrocyanide, 428, 465. Copper, occurrence and preparation, 460. Copper, oxides of, 462. Copper purified by electrolysis, 461, 465. Copper pyrites, 171, 460. Copper, salts of, 403-465. Correlation and conservation of energy, 13. Corrosive sublimate, 401. Corundum, 407, 409. Crafts-Friedel reaction, 411. Critical density, 284. Critical temperature and pressure, 60, 283. Critical volume, 284. Crocoisite, 445, 478. Crookes, discoverer of thallium, 417. Cry of tin, 484. Cryolite, 168, 313, 407, 412. Crystallization, fractional, 157. Crystallization or freezing, 50. Crystallization, water of, 46. Crystalloids, 301. CupellatiQn, 468. Cupric compounds, 462. Cuprite, 460. Cuprous compounds, 462. Curie, M. and Mme., on XBdioactive substances, 458. Cyanic acid, 290. Cyanic acid, sulpho-, 290. Cyanide process, 475. Cyanine, 215. Cyanogen, 289. Daguerre, 472. Daguerreotype, 472. Dal ton, on the atomic theory, 12. Daniell cell, 395. Davy prepares potassium, 388. Davy prepares sodium, 313. Davy safety lamp, 295, 493. Deacon's process for making chlorine, 116. Decomposition, double, 328. Decomposition, heat of, and of forma- tion, 22. Decrepitation of sodium chloride, 317. Deliquescent, 322. Densities and molecular weights of gases, 82. Densities of gases, determination of molecular weights from, 70. Density, critical, 284. Detonating gas, 85. Detonating gas, chlorine and hydrogen, 121. " Developer," 471. Dewar, liquefaction of fluorine, 167. Dewar, liquefaction of oxygen, 28. Dewar liquefied and froze hydrogen, 48. Diacid base, 211. Diagram of sulphur, temperature-press- ure, 174. Diagram of water, temperature-pressure, 58. Dialysis, 301, 424. Dialyzer, 301. Diamond, 272. 506 INDEX m\. Diamorphism, 172, 900. Diaspare, 409. Dibasic acid, 212. Dichromates, 450. Dielectric constant of water, 61. Diffusion of gases, law of, 4f. Disinfectant, 66. Disinfectant, chlorine, 118. Dissociating power of water, 63. Dissociation by heat, 162. Dissociation by heat, of ammonium chloride, 357. Dissociation calcolated from condnc- tiYity measurements, 114. Dissociation electrolytic, 64. Dissociation electrolytic, measurement of. 111. Dissociation, hydndytic, 249. Dissociation, natore of conditioned by the presence of another sobstance, 389. Dissociation of ammonium hydroxide, 222. Dissociation of a weak base^ measure- ment of, 222. Dissociation of copper sulphate in its water of crystallization, 465. Dissociation of diy ammonium chloride, 357. Dissociation of hydrogen sulphide, 181. Dissociation of nitrates, 232. Dissociation of nitric acid, 232. Dissociation of sulphuric acid, 191. Dissociation of vapors diminished by an excess of one of the products of dissociation. 91. Dissociation, origin of the theory of electrolytic, 109. Dissolved substances affect the proper- ties of water, 63. Dissolved substances, determination of the molecular weights of, 82. Dissolved substances, molecular weights of, determined by the boiling-point method, 95. Dissolved substances, molecular weights of, determined by the freezing-point method, 93. Distance, chemical action at a, 425. Disthene, 414. Distillation, 49. Distillation fractional, dS. Disulphuric acid, 104. Ddbereiner lamp, 494. D5bereiner triads, 130. Dog*s grotto, 280. Dolomite, 381, 386. Double decomposition, 323. Drummond light, 364. Dry ammonia does not act oi hydrochloric acid, 203. Dry chlorine, inactivity of, 121. Dry hydrochloric acid does not a dry ammonia, 203. Dry hydrogen will not oombiiie dry oxygen, 38. Dulong and Petit's law, 75. Dulong and Petit, specific hemt o bon, 276. Dumas, method of, 82. Dynamic condition of eqoilibriain Earth, composition of, 6. Earthenware or stoneware, 415w Effervescent water, 48. Efflorescent, 324, 326. Ekaaluminhim, 149, 419. Ekaboion, 149, 416. Ekasilicon, 149. Electric furnace, 273. Electricity, amount of, 361. Electricity, potential of, 361. Electric light, 296. Electro-chemical theories of da and Williamson, 110. Electrolysis, 60. Electrolysis of hydrogen, 45. Electrolysis of potassium hydro; theory of, 335. Electrolysis of water, 50. Electrc^ytes, 63. Electrolytic dissociation, 64. Electrolytic dissociation, me&sorei of. 111. Electrolytic dissociation, origin of theory of, 109. Electrol^-tic dissociation, theory 110. INDEX 507 Electrolytic dissociation, theory of and osmotic pressure, 100. Electrolytic gas, 35. Electrolytic gas, chlorine and hydro- gen, 121. Electrolytic method of preparing chlo- rine, 117. Electrolytic process, 468. Electrolytic purification of copper, 466. Electro-plating, 4S4. Elements and compounds, 3. Elements and compounds, number of, 3. Elements, chemical, 4. Elements predicted by means of the Periodic System, 147. Enantiotropic, 172. Enantiotropic mercuric iodide, 403. Endothermic reaction, 225. Energy, different amounts in oxygen and ozone, 31. Epsom salt, 385. Equation, chemical, 6. Equilibrium, 180. Equilibrium, dynamic condition of, 180. Equilibrium metastable, 60. Equivalent normal solution, 211. Esters, 288. Ether, 288. Ethylene hydrocarbons, 277. Eudiometric method, 236. Eutectic alloy, 267. Euxenite, 416, 417. Faraday, liquefaction of chlorine from chlorine hydrate, 110. Faraday's law the basis of chemical valency, 134. Feldspars, 407, 414. Ferrates, 430. Ferric acid, 430. Ferric compoimds, 423-430. Ferrocyanic acid, hydro-, 427, 428. Ferrocyanide of copper, 428. Ferrocyanide of potassium, 427, 428. Ferrous compounds, 423-426. Filtration, 48. '* Fixing" agent in photography, 325. Flame, effect of cooling, 205. Flame, oxidizing, 204. Flame, reducing, 203. Flames and their luminosity, 202. Flint, 300. Flowers of sulphur, 171. Fluorescence, 365. Fluorine, 165. Fluorine, compound with iodine, 160. Fluorine, liquefaction of, 167. Fluorine, occurrence and preparation, 165. Fluor spar, 165, 363. Flux, 330. Formation, heat of, and of decomposi- tion, 22. Fractional crystallization, 157. Fractional distillation, 65. Franklinite, 387. Franklin, work on liquid ammonia, 206. Freezing of water, 55. Freezing, or crystallization, 60. Freezing-point apparatus of Beckmann, 94. Freezing-point method of determining the naolecular weights of dissolved substances, 03. Freezing-point of water, 63. Friedel-Craft^s reaction, 411. Fulminating mercury, 405. Fuming nitric acid, 232. Furnace, electric, 273. Fusible white precipitate, 406. Fusion, heat of, of ice, 56. Gadolinite, 306, 416, 417. Gahnite, 410. Galena, 171, 478. GaUium, 416. Galvanized zinc, 388. Garnets, 374, 415. Gamierite, 433. Gases, determination of the molecular weights of, 82. Gases, law of Boyle for, 24. Gases, law of Gay-Lussac for, 26. Gases, permanent, 43. Gas law as applied to osmotic pressure, exceptions, 108. Gas-pressure and osmotic pressure, causes of, 107. 608 INDEX Gas-pressure and osmotic pressure, equality of, 107. Gas-pressure and osmotic pressure, re- lations between, 104. Gas to liquid, continuity of passage from, 285. Gay-Lussac and Boyle, combined ex- pression of the laws of, 26. Gay-Lussac, law of for gases, 26. Gay-Lussac, method of for determin- ing molecular weights, 84. Gay-Lussac, numbers of atoms in equal volumes of different gases, 71. Gay-Lussac showed elementary nature of chlorine, 115. Gay-Lussac 's law for osmotic pressure, 106. Gay-Lussac tower, 188. Generalizations, 7. Germanium, 306. Germanium, compounds of, 805. German silver, 388, 434, 462. Gersdorffite, 433. Gibbs, Willard, phase rule of, 69. Gilchrist-Thomas, converter, 422. Glacial phosphoric acid, 261. Glasses, colored, 374. Glass, different varieties of, 374. Glauber's salt, 323. Glazing of porcelain, 415. Glover tower, 188. Glucinum, .383. Gluoinum, compounds of, 383. Gneisses, 298. Gold, 474. Gold, colloidal solution of, 476. Gold, fooPs, 426. Gold, metallurgy of, 474. Gold, oxides and hydroxides of, 477. Gold plating, 476. Gold, properties of, 476. Gold, salts of, 477. Goldschmidt method of preparing chromium, 446. Goldschmidt method of preparing tung- sten, 455. Gold telluride, 474. Granites, 298. Graphite, 272. Greenockite, 897. Grotto, dog's, 280. Groups, relations within the, 144 Guldberg and Waage's law of action, 92. Gun-metal, 462. Gunpowder, 343. Gypsum, 363, 367. Hall method of preparing alumj 408. Halogen acids, comparison of the Halogens, compounda with tx>ron Hard water, 47. Hard waters, 871. Hausmannite, 436. Heat, dissociation by, 162. Heat energy produced when o: and hydrogen combine, 37. Heat of combustion, measoreme] 21. Heat of condensation of steam, a solidification of water, 56. Heat of formation and of decoD tion, 22. Heat of fusion of ice, 56. Heat of neutralization, 217. Heat of neutralization, explanati constant, 218. Heat of vaporiz?ition of water, 54. Heavy spar, 378. Heinrich Rose points out that cates are being converted inU bonates, 802. Helium, 240. Hematite, 419, 423. Henry's law, 63. Hess, law of the thermoneutrali salt solutions, 220. Hofmann, modification of Gay-Lua method, 84. Homologous series of compounds. Homologous series of silicic acids. Hornblende, 384, 387. Horn -silver, 467. HUbnerite, 465. Hydrargillite, 409. Hydration, water of, 46. Hydraulic cement, 370, 410. INDEX 609 Hydraulic minin'g, 474. Hydrazine, 202. Hydrazine, properties of, 208. Hydrazoic acid, method of formation, 208. Hydride of lithium, 353. Hydride of sodium, 315. Hydride of tellurium, 199, Hydrides, 40. Hydnodic acid, 161. Hydrobromic acid, 155. Hydrochlorauric acid, 477. Hydrochloric acid, 121. Hydrochlorpalladic acid, 401. Hydrochlorplatinic acid, 496. Hydrochlorplatinous acid, 496. Hydrochlorplumbic acid, 481. Hydrochlorstannous acid, 487. Hydrocyanic acid, 290. Hydroferricyanic acid, 428. Hydroferrocyanic acid, 427. Hydrofluoric acid, 168. Hydrofluosilicic acid, 804. Hydrofluozirconic acid, 306, Hydrogen, 33. Hydrogen, action on chlorine, 118. Hydrogen and chlorine, volume rela- tions in which they combine, 121. Hydrogen and hydroxyl ions combine when in the presence of one an- other, 215. Hydrogen and nitrogen, compounds of, 209. Hydrogen and nitrogen, volume rela- tions in which they combine, 202. Hydrogen, combination with oxygen, 35. Hydrogen, compounds of with metals, 89. Hydrogen, compounds with sulphur, 177. Hydrogen diffuses rapidly, 41. Hydrogen dioxide, 64. Hydrogen dioxide a good oxidizing agent, 66. Hydrogen dioxide also a reducing agent, 66. Hydrogen dioxide and water, relations between, 67. Hydrogen dioxide, catalytic decompo- . sition of, 67. Hydrogen dioxide, preparation and purification, 64. Hydrogen dioxide used in preparing oxygen, 16. Hydrogen, discovered by Cavendish, 33. Hydrogen, dry, will not combine with dry oxygen, 38. Hydrogen, electrolysis of, 45. Hydrogen, liquefaction of, 42. Hydrogen liquid, Dewar's experiment with, 44. Hydrogen nascent, 40. Hydrogen persulphides, 183. Hydrogen present in all acids, 40. Hydrogen, reducing power of, 38. Hydrogen selenide, 198. • Hydrogen silicide, 299. Hydrogen, solidification of, 43. Hydrogen spectrum, 44. Hydrogen sulphide, 177. Hydrogen sulphide a dibasic acid, 181. Hydrogen sulphide, dissociation of, 181. Hydrolysis, 213, Hydrolysis of carbonates, 282, 328. Hydrolytic dissociation, 240, 323. Hydroscopic substancCi 223. Hydrosulphide of calcium, 367. Hydrosulphides, 181. Hydroxylamine, 223. Hydroxyl and hydrogen Ions combine when in the presence of one another, 215. Hydroxyl compounds include all 1 210. *' Hypo," 194, 325, 471. Hypobromous acid, 157. Hypochlorite of calcium, 366. Hypochlorous acid, 128, Hyponitrous acid, 228. Hypophosphoric acid, 251. Hypophosphorous acid, 252. »* Hyposulphite," 194. Ice, artificial, preparation of, 206. Ice, heat of fusion of, 56. Iceland spar, 368. 610 INDEX Ice machiues, Carr^f 206. Illumination, 201. Imperfections in the Periodic System, 161. Indicators, 212. Indicators, acidic, 213. Indicators, basic, 215. Indicators, theory of, 212. Indium, 417. Inductive capacity, specific, of water, 61. Infusible white precipitate, 406. Ink, sympathetic, 482. Intensities of light, measurement of relative, 297. Iodic acid, 163. Iodide of nitrogen, 233. Iodine, 158. Iodine, compounds with oxygen and hydrogen, 163. Iodine, compound with bromine, 165. Iodine, compound with chlorine, 165. Iodine, compound with fluorine, 169. Iodine, detection of, 159. Iodine, detection of in the presence of bromine and chlorine, 160. Iodine, molecular weight in the form of vapor, 161. Iodine, occuiTence and preparation, 158. Iodine pentafluoride, 169. Iodine, tincture of, 161. Ion, chlorine, and the ion of chlorates, 131. Ion formatiori, modes of. 111, 425, 466, 476. Ions, 64, 110. Ions, chromic and dichromic, 461. Ions the active agents chemically, 429. Iridium, 492. Iridium compounds, 492. Iridium-osmium, 492. Iridium-platinum, 492. Iron bums in oxygen, 17. Iron chromite, 446. Iron, impure or commercial, 421. Iron, occurrence and preparation, 419. Iron oxides, 423. Iron pentacarbonyl, 279. Iron, rusting of, 420. Iron sesquisulphide, 426. Iron, Spiegel, 421, 437. Iron, sulphides of, 426. Iron vitriol, 426. Iron, welding of, 420. Iron, wrought, 421. Isomeric substances, 227. Isomorphism among the alums, 4 Isomorphism, an aid in detem atomic weights, 77. Isomorphous substances, 267. Itacolumite, 272. Jasper, 300. Jones's boiling-point apparatus, 9 Kainite, 345, 384. Kaolin, 407, 414. Kelvin, on the size of atoms, 12. Ketones, 288. Kieserite, 384. Kindling temperature, 295. Kinetic theory of liquids, 286. Kipp apparatus, 86, 116. KirchhofT and Bunsen, discoYe] rubidium, 354. Kux:hhofr and Bunsen's law of absorption, 45. Kohlrausch, law of, 222. Kohlrausch, method of measuring ductivities, 112. Kopp, molecular heats the sum o atomic heats, 76. Krypton, 241. Kundt^s method of determining velocity of sound in a gas, 240. Lamp-black, 274. Lamp, safety, 295. Landolt, on the law of the conservj of mass, 9. Langbeinite, 385. Lanthanum, 417. Lapis lazuli, 416. Laughing gas, 224. Lavoisier explains rOle of oxyge; combustion, 19. Lead, 478. Leaden chamber, 188. INDEX 611 Lead, hard, 266. Lead, hydroxides of, 480. Lead, occurrence, preparation, and properties, 478. Lead, oxides of, 470. Lead precipitated by metals, 479. Lead salts, 481-483. Lead, sugar of, 483. Lead tree, 479. Lead, vinegar of, 483. Lead vitriol, 482. Le Blanc, method of preparing sodium carbonate, 326. Leclanch^ cell, 439. Lecoq de Boisbaudran discovered eka- aluminiuro — gallium, 149,416. Lepidolite, 352, 354. Leucite, 354. Light, electric, 296. Light, intensities of, measurement of relative, 297. Light, Welsbach, 296. Lime, 363. Lime, air-slaked, 365. Lime, soda, 365. Limestone, 363, 369. Lime water, 364. Linde, liquefaction of oxygen, 27. Liquids, kinetic theory of, 286. Liquid to gas, continuity of passage from, 285. Litharge, 479. Lithium, compounds of, 352-353. Lithium, discovery, preparation, and properties, 352. Lithium hydride, 353. Lithium ion, characteristic reaction of, 362. Litmus, 214. Lothar Meyer's Periodic System, 137. Low temperatures, measurement of, 43. Luminescence, 367. Luminosity, effect of pressure on, 293. Luminosity of flames, 292. Luminosity of flames affected by acety- lene, 293. Lunar caustic, 473. Luray cave, 371. Luteo compounds, 433. Lycopodiom powder, 240. Lye, 333. • Magnalium, 409. Magnesia, 384. Magnesia alba, 386. Magnesite, 384. Magnesium, 384. Magnesium, compounds of, 384-386. Magnesium nitride, 387. Magnesium platinocyanide, 497. Magnesium, separation of from the ele- ments of the calcium group, 387. Magnesium silicates, 386. Magnetite, 419, 423. Malachite, 460, 465. Mammoth cave, 371. Manganates, 437. Manganese, 436. Manganese, alloys of, 436. Manganese blende, 438. Manganese bronze, 436, 462. Manganese, hydroxides of, 437. Manganese, occurrence, preparation, and properties; 436. Manganese, oxides of, 436. Manganese spar, 439. Manganese tetravalent, 439. Manganese, valence and properties of, 439. Manganic acid, 437, 440. Manganic acid, per-, 437. Manganic compounds, 439. Manganites, 437. Manganous acid, 437, 440. Manganous salts, 437. Mannheim gold, 485. Mantle to Welsbach light, 296. Marble, 353, 363, 369. Marignac, on atomic weights, 80. Marl, 414. Marsh's method for detecting anti- mony, 262. Marsh's method for detecting arsenic, 255. Martin-Siemens process, 422. Mass action, 346. Mass action, law of, 91. Mass, effect in quantitative analysis, 474. 512 INDEX Mass, efFect of, on chemical activity, 30. Massicot, 470. Mass, law of the conservation of, 8. Mass on chemical action, effect of, 302. Mass or size of an atom, 12. Matches, safety, 330. Matte, 460. Membranes, semi-permeable, 428. Mendel^eff's Periodic System, 137. Mercuric and mercurous oxides, 400. Mercuric compounds, 401-406. Mercuric oxide used in preparing oxy- gen, 16. Mercurous compounds, 400-406. Mercury, fulminating, 405. Mercury, molecular weights of metals in, 309. Mercury molecule is monatomic, 399. Mercury, properties of, 398. Mercury, purification of, 398. Mercury salts, action of ammonia on, 405. Mercury salts, only slightly dissociated^ 401. Metals, 310. Metameric compounds, 229. Metastable equilibrium, 60. Metathesis, 323. Methane hydrocarbons, 277. Methyl orange, 214. Mica. 374, 407, 415. Microcosmic salt, 329, 360. Milk of lime, 364. Minesite, 345. Mining, placer, vein, hydraulic, 474. Minium, 480. Mirrors, 469. Mitscherlich, on isomorphism an aid in determining atomic weights, 77. Mohr method of determining silver, 474. Moissan, 272, 296, 414. .Moissan, apparatus and method for preparing fluorine, 166. Molecular conductivities, 112. Molecular normal solution, 211. Molecular weights and Avogadro's hy- pothesis, 72. Molecular weights, atomic weights from, 73. Molecular weights determined from the densities of gasles, 70. Molecular weights of dissolved 8ul>- stances determined by the boiling- point method, 95. Molecular weights of dissolved sub- stances, determined by the freez- ing-point method, 93. Molecular weights of gases and of dissolved substances, 82. Molecular weights of gases, determina- tion of, 82. Molybdenite, 453. Molybdenum, 453. Molybdenum, compounds of, 453- 464. Molybdic acid, 453. Molybdic acid, phospho-, 454. Monacid base, 211, 212. Monazite sand, 306, 417. Monobasic acid, 212. Monotropism, 172. Mordant, 413. Morley, on the ratio of hydrogen to oxygen, 80. Morse's method of preparing chromic acid, 449. Morsels method of preparing perman- ganic acid, 441. Morse's method of preparing semi-per- meable membranes, 102. Mortar, 370. Mosaic gold, 488. Muddy water, 48. Multiple proportions, law of, 10. Murium, 115. Nascent hydrogen, 40. Nature, tlie study of, 1. Needle valve, 238. Negative photograph, 471. Neodymium, 270. Neon, 241. Nemst's law of saturation, 318. Nessler's reagent, 403. Neutralization, explanation of the con- sUnt heat of, 218. Neutralization of acids and bases, 210, 217. IKDEX 613 Neutralization of weak acids and bases, 219. New elements predicted by the Periodic System, 147. Newland^s octaves, 136. Niccolite, 433. Nickel, 433. Nickel carbonyl or tetracarbonyl, 484. Nickel, compounds of, 434. Nickel-plating, 434. Nickel tetracarbonyl, 279. Nilson discovered ekaboron — scandium, 149. Nilson, discoverer of scandium, 416. Nitric acid, 229. Nitric oxide, 225. Nitride of boron, 808. Nitride of magnesium, 387. Nitrifying ferment, 341. Nitrogen, 200. Nitrogen and hydrogen, compounds of, 209. Nitrogen and hydrogen, volume rela- tions in which they combine, 202. Nitrogen, compounds with chlorine, bromine, and iodine, 233. Nitrogen, compounds with oxygen, hy- drogen, and sulphur, 221, 233. Nitrogen dioxide, 226. Nitrogen iodides, 233. Nitrogen, occurrence and preparation, 200. Nitrophenol-p, 214. Nitroprussiate of sodium, 429. Nitrosulphonic acid, 189, 234. Nitrosyl chloride, 233. Nitrosyl-sulphuric acid, 189, 233. Nitrous acid, 229. Nitrous oxide, 224. Nitryl chloride, 233. Non-electrolyte8» 63. Normal solution, 112. Normal solution, equivalent, 211, Normal solution, molecular, 211. Octaves of Newlands, 136. Octivalent, 134. Oil-lamp, 291. Olivine, 387. 2l Olszewski and Wroblewskl, liquefaction of oxygen, 28. Onyx, 300. Opal, 300. Orthoclase, 414. Osmium, 491. Osmium salts, 492. Osmium tetroxide, 491. Osmotic pressure, 100. Osmotic pressure and gas-pressure, causes of, 107. Osmotic pressure and gas-pressure, equality of, 107. Osmotic pressure and gas-pressure,. relations between, 104. Osmotic pressure and the theory of electrolytic dissociation, 100. Osmotic pressure, Boyle's law for, 105. Osmotic preasure, demonstration of, 100. Osmotic pressure, exceptions to the applicability of the gas-laws to, 108. Osmotic pressure, Gay-Lussac's law for, 105. Osmotic pressure, Morse's method of measuring, 102. Osmotic pressure of solutions, Avo- gadro's law applied to, 106. Osmotic pressure, Pfeffer's measure- ments of, 103. Ostwald, color of permanganates, 443. Oxidation, slow and rapid, 21. Oxidizing flame, 294. Oxygen, 15. Oxygen, allotropic modification of, 29. Oxygen and hydrogen, heat energy pro- duced when they combine, 37. Oxygen and hydrogen, mixture of afFected by the presence of certain substances, 36. Oxygen and hydrogen, relations by volume in which they combine, 36. Oxygen and ozone, different amounts of energy in, 81. Oxygen, combination with hydrogen, 35. Oxygen, difference between, and ozone, 31. Oxygen, dry, will not combine with dry hydrogen, 38. 514 INDEX Oxygen, liquefaction of, 26. Oxygen means acid-fonner, 124. Oxygen, names of compounds formed with, 23. Oxygen, occurrence in nature, 16. Oxygen, physical properties of, 24. Oxygen, power of entering into chemi- cal combination, 29. Oxygen, preparation of, 15. Oxygen, pressure of varies with the conditions, 24. Oxygen, properties of liquid, 28. Oxygen, rdle of in combustion, 10. Oxygen, substances burn readily in, 16. Oxygen, transformation of ozone into, 31. Oxygen used up in combustion, 20. Oxyhydrogen blowpipe, 37. Ozone, 29. Ozone and oxygen, different amounts of energy in, 31. Ozone, difference between and oxygen, 31. Ozone, preparation of, 29. Ozone, transformation of into oxygen, 31. Palladic acid, hydrochlor-, 401. Palladium, 490. Palladium hydride, 490. Palladium oxides, 491. Palmaer demonstration of the solution- tension of mercury, 391. Paris, plaster of, 368. Parke's method, 468. Passive condition, 421. Passive stat«, 232. Pattinson process, 408. Pebal's experiment, 89. Periodic System, 130. Periodic System, imperfections in the, 160. Periodic System of Brauner, 141. Periodic System of Mendel^ff and Lothar Meyer, 137. Periodic System used to correct atomic weights, 147. Periodic System used to predict the existence of new elements, 147. Permanent gases, 43. Permanganates, color of, 443. Permanganic acid, 437, 441. Permanganic acid, Morse's method of preparing, 441. Permonosulphurio acid, 195. Petit and Dulong's law, 75. Pewter, 479. Pfefifer's measurements of osmotic pressure, 103. Phase rule of Willard Gibbs, 59. Phenolphthaleln, 213. PhenolphthaleKn cannot be used with weak acids nor bases, 213. Philosopher's wool, 388. Phlogiston theory of combustion, 18, Phosgene, 279. Phosphine, 246. Phosphomolybdic acid, 454. Phosphonium iodide, 246. Phosphorescence, 367. Phosphorite, 242, 372. Phosphorus, 242. Phosphorus, acids of, 247. Phosphorus bronzes, 462. Phosphorus burns in oxygen, 17, Phosphorus, compounds with hydro- gen, 245. Phosphorus, compounds with oxygen and hydrogen, 246. Phosphorus, compounds with the halo- gens, 253. Phosphorus, metallic, crystallized, or black, 244. Phosphorus oxychloride, 254. Phosphorus pentachloride, 253. Phosphorus pentachloride, ▼aix>r de- composed by heat, 253. Phosphorus, red, 243. Phosphorus, strengths of the acids of 252. Phosphorus, white, 244. Phosphorus, yellow, 243. Photochemical reactions, 118. Photography, 471. Photometer, Bunsen, 207. Photophone, 197. Physical properties and atomic weights, 145. INDEX 515 Physics and chemistry, relatioiui be- tween, 1. Pictet, liquefaction of oxygen, 27. Pig-iron, 420, 421. Pink salt, 487. Pitchblende, 466. Placer mining, 474. Plantations, saltpetre, S41. Plaster of Paris, 368. Platinic acid, hydrochlor-, 496. Platinonitrite of potassium, 407. Platinous acid, hydrochlor-, 496. Platinum black, 498. Platinum, chlorides of, 496. Platinum, colloidal solution of, 495. Platinum, double cyanides of, 497. Platinum-iridium, 492. Platinum, oxides and hydroxides of, 496. Platinum resistance thermometer, 43. Platinum sponge, 493. Platinum, sulphides of, 497. Platinum, uses of, 494. Pleonast, 410. Plumbago, 273. Plumbates, 480. Plumbic acid, hydrochlor-, 481. Plumbic acid, meta-, 480. Plumbic acid, normal, 480. Plumbites, 480. Point, transition, 172. Pollux, 35'). Polonium, 458. Polymeric substances, 227. Polymorphism, 172. Porcelain, 415. Portland cement, 370. Positive photograph, 472. Potash, 336. Potash caustic, 336. Potash, red prussiate of, 428. Potash, yellow prussiate of, 427. Potassium amide, 340. Potassium bromide, 339. Potassium carbide, 340. Potassium chlorate, used in preparing oxygen, 16. Potassium, detection of, 361. Potassium does not act with dry oxy- gen, 334. Potassium ferricyanide, 428. Potassium ferrocyanlde, 427. Potassium hydrazoate, 340. Potassium hydride, 336. Potassium hydroxide, 335. Potassium hydroxide prepared by the electrolysis of the chloride, 335. Potassium ion, characteristic reaction of, 362. Potassium nitrate solubility curves, 342. Potassium, occurrence and preparation, 333. Potassium permanganate, 441. Potassium peroxide, 336. Potassium persulphate, 345. Potassium phosphorus, 348. Potassium platinonitrite, 497. Potassium, preparation of, 334. Potassium pyroantimoniate, 349. Potassium, salts of, 337-350. Potassium silicates, 249. Potassium silicofluoride, 349. Potassium silver cyanide, 473. Potassium subchloride, 338. Potassium tetroxalate, 351. l^otential of electricity, 361. I'raseo compounds, 433. Praseodymium, 270. Pressure, critical, 60, 283. Pressure, effect of on luminosity, 293. Pressure-temperature diagram of sul- phur, 174. Pressure-temperature diagram of water, 58. Priestley and Scheele discover oxygen, 19. Prince Rupert drops, 376. Principle of Soret, 106. Proportion, law of constant, 9. Proportions, law of multiple, 10. Proust, on the law of constant propor- tion, 10. Prout's hypothesis, 136. Prussian blue, 427. Prussiate, red, of potash, 428. Prussiate, yellow, of potash, 427. Pnissic acid, 290. 616 INDEX Pseudosolutions, 301. Purple of CassiuB, 476. l^lrpureo compouirds, 433. Pyrargyrlte, 467. Pyrites, 171, 410. l^rites, arsenical, 256. Pyrites, copper, 171. Pyrolusite, 436. Quadrivalent, 134. Quartation, 475. Quartz, 298. Quinquivalent, 134. Radiation, uranium, 457. Radioactive substances, 458. Radioactivity, 468. Radiograplis, 467. Radium, 468. Ramsay determines the number of atoms in the molecule of argon, 240. Ramsay discovers argon, 239. Ramsay places rare elements in the atmosphere, in the Periodic System, 151. Rapid and slow oxidation, 21. Reaction, catalytic, 187. Reactions, reversible, 30. Reactions, reversible chemical, 170. Heaction, yield of, 180. Reducing flame, 203. Reducing power of hydrogen, 38. Regnault, molecular heats the sum of the atomic heats, 76. Resistance of water, 63. Resistance thermometer of platinum, 43. Reversible chemical reactions, 30, 170, 348. Revert phosphoric acid, 373. Rhodium, 4iK). Rhodocroisite, 436. Richards, on atomic weights, 80. Rock crystal, 300. Rock salt, 116. Rj,Ontgen rays, 457. Rose, on mass action, 346. Rose's fusible metal, 267. Rotatory power of sodium chlorate, 321. Rouge, 423. Rubidium dioxide, 364. Rubidium hydroxide, 354. Rubidium, occurrence, preparation, properties, 364. Rubidium, salts of, 354. Ruby, 407, 400. Rupert drops, 376. Rusting of iron, 420. Ruthenate of potassium, 489. Ruthenium, 480. Rutherford, on radioactiylty, 458. Rutile, 305. Safety lamp, 205. Safety matches, 330. Sal ammoniac, 203, 357. Saltpetre, 333. Saltpetre bacteria, 341. Saltpetre, Chili, 312. Saltpetre, India crude, d41. Saltpetre plantations, 341. Saltpetre, soda, 168. Salt«, 215. Salts, acid, 216. Salts, basic, 216. Salts, formed from anion of acid and cation of base, 215. Salts, nomenclature of, 215. Salt solutions, explanation of the law of the thermoneutrality of, 220. Samarium, 418. Samarskite, 306. Sand, 298. Sandstone, 300. Sapphire, 407, 400. Saturated solutions, 61. Saturation, law of, 318. Scandium, 416. Scheele and Priestley discover oxygen, 19. Scheelite, 455. Schlippe's salt, 266, 331. Sch(5nite, 385. Selcnic acid, 108. Selenide of hydrogen, 108. Selenious acid, 108. Selenium, 197. Selenium, compounds of, 198. D^DEX 617 Seleniam, metallic, 107. Semi-permeable membranes, Morse's method of preparing, 102, 428. Senarmontite, 262. Septivalent, 134. Serpentine, 384, 386. Shapleigh, Waldron, 271. Siderite, 410. Siemens-Martin process, 422. Silicates converted into carbonates, 302. Silicates, double, 414. Silicon, 208. Silicon, acids of, 300-301. Silicon, amorphous, 200. Silicon bromoform, 303. Silicon chloroform, 303. Silicon, compounds with the halogens, 303. Silicon, compound with carbon — carbo- rundum, 304. Silicon crystalline, 208. Silicon dioi^ide, 200. Silicon hydrides, 200. Silicon iodoform, 303. Silicon, preparation of, 208. Silver, 467. Silver, alloys of, 460. Silver, colloidal, 468. Silver, German, 388. Silvering, 460. Silvering of glass, 460. Silver ion, 470. Silver oxides and hydroxid, 470. Silver-plated wares, 460. Silver-plating, 460. Silver, preparation of, 467. Silver, salts of, 470-474. Silver, spitting of, 468. Silver triazoate, 473. Size or mass of an atom, 12. Slaked lime, 304. Slow and rapid oxidation, 21. Smalt, 432. Smaltite, 431. Smithsonite, 387. Soapstone, 387. Soda-lime, 366. Soda saltpetre, 158. Sodium, 312. Sodium aluminate, 410. Sodium amide, 321. Sodium ammonium phosphate, 320. Sodium chlorate rotates plane of polar- ized light, 321. Sodium, compounds with the halogens, 317. Sodium dry, does not act on dry sul- phuric acid, 314. Sodium halides, solubilities of, 320. Sodium hydride, 316. Sodium hydroxide, 316. Sodium ion, characteristic reactions of, 362. Sodium ion, the active agent, 316. Sodium nitroprussiate, 420. Sodium, occurrence of, 312. Sodium, preparation of, 313. Sodium pyroantimoniate, 331. Sodium, salts of, 310-331. Sodium subchloride, 310. Sodium sulphate, solubility curves of, 326. Sodium sulphite, hydrolytic dissociation of, 323. Sodium triazoate, 321. Sodium water-glass, 331. Soft solder, 486. Solder, 3:30. Solder, soft, 486. Solfatara, 171. Solidification of water, heat of, 66. Solubility, limited and unlimited, 62. Solubilities of sodium halides, 320. Solution, equivalent normal, 211. Solution, molecular normal, 211. Solutions, pseudo-, 301. Solutions, supersaturated, methods .of preparations, 62. Solutions, unsaturated, saturated and supersaturated, 61. Solution-tension of metals and pri- mary cells, 303. Solution-tension of metals, demonstra- tion of, 301. Solution-tension of some of the more common metals, the relative, 303. Solvay or ammonia process of prepar- ing ammonium carbonate, 827. 618 INDEX Solvent power of water, 61. Soot, 274. Soret principle, 106. Spec t tic heat of boron varies with the temperalure, 307. Specific heat of water, 60. Specific beats, ut^jmic weights from, 76. Specific inductive capacity of water, 61. Spectroscope, 46. Spiegel bronze, 462. Spiegel iron, 421, 437. Spinel, 410. Spiritus fumans Libavii, 487. Spitting of silver, 468. Spoduinene, 352. Sponge, platinum, 493. SUnoates, 480. Siannate, sulpho-, 487. Stannic acid^ 480* Staanoaa acid» hydropblor-, 487. Stannous and stannic hydroxides, 486. Stannous and stannic oxides, 486. Stannous chloride, 486. . Stalactites, S71. Stalagina, 371. Stalagmites, 371. Stas, on atomic weights, 80. Steam, heat of condensation of, 66. Steel, 422. Steel, Bessemer, 422. StLTL (list nil erism^ 229. Stibine, 261. Stibnite, 171. Still, 49. Stokes, on Rontgen rays, 467. Stolzite, 465. Stoneware or earthenware, 416. Storage battery, 483. Storage cells, 193. Strass, 374. Stromeyerite, 467. Strontianite, 376. Strontium, detection of, 377. Strontium, occurrence, preparation, propertiew, 376. Strontium, salts of, 377. Study of nature, 1. Sublimation of iodine, 161. Substitution, 119. Sugar of lead, 483. Sulphide, hydrogen^ 177. Sulphides, 172. Sulphides, acid, 181. Sulphoeyanic acid, 290. Sill phonic acid, nitro-^ 2S4. Sulpliur hiiius in oxygen, 17. Sulphur, compounds with chlorine, 19& Sulphur, compounds with hydrogen, 177. Sulphur, compounds with hydrogen and ojcygen, liig. Sulphur^ com pounds with oxygen and hydrogen, 184, Sulpiiur, compounds with the halogens and sulphur 105, Sulphur, difference between the poly- morphous formfl, 172. Sulphur, flowers of, 171. Sulphuric acid, 187. Sulphuric acid, chlor-, 106. Sulphuric acid, di-, 194. Sulphuric acid, dissociation of, 191. Sulphuric acid dry, does not act on dry sodium, 314. Sulphuric acid, nitrosyl-, 189, 233. Sulphuric acid, per-, 194. Sulphuric acid, permono-, 195. Sulphuric acid, pyro-, 194. Sulphuric acid, thio-, 194. Sulphur, occurrence and purification 171. Sulphurous acid, 186. Sulplmrous acid, hydro-, 194. Sulphurous acid, strength of, 186. Sulphur, roll or slick, 171. Sulphur, temperature- prtBsur© diagram of, 174. Sulphur, vapor-density of, 174. Sulphur water, 48. Sulphuryl chloride, 196. Sulphuryl chloride, pyro-, 196. Supercooling and superheating of water 66. Supercooling, removal by solid phase of same substance, 67. Superheating and supercooling of water 66. ' INDEX 519 Supersatarated solutions, 61. Supersaturated solutions, methods of preparation, 62. Sylvine, 116, 837. Sylvite, 333. Sympathetic ink, 432. Talc, 384, 386. Tantalum, 271. Tartar emetic, 263. Telluric acid, 100. Tellurious acid, 100. Tellurium, 108. Tellurium, compounds of, 100. Tellurium hydride, 100. Temperature, critical, 60, 283. Temperature, determination of the ab- solute, 26. Temperature, kindling, 205. Temperature-pressure diagram of sul- phur, 173. Temperature-pressure diagram of water, 68. Tempering of steel, 423. Ternary electrolyte, li2. Thallium, 417. Thanhs experiment, 00. Thenardite, 323. Thermometer of Beckmann, 05. Thermometer, platinum resistance, 43. Thermoneutrality of salt solutions, ex- planation of the law of, 220. Thilorier*8 mixture, 283. Thionic acids, poly-, 105. Thomas-Gilchrist converter, 422. Thomas slag, 422. Thomson, J. J., electrolyzed hydrogen, 45. Thorite, 306, 418. Thorium, 306. Tin, 484. Tin, allotropic forms of, 485. Tin, alloys of, 485. Tin-butter, 487. Tin, cry of, 484. Tincture of iodine, 161. Tin ions, 485. Tin-pest, 485. Tin, preparation and properties of, 484. Tin-salt, 487. Tinstone, 484. Tin, sulphides of, 487. Titanic acid, 305. Titanite, 305. Titanium, 305. Titanium, compounds of, 905. Topaz, oriental, 400. Tourmaline, 352, 387. Towers, Glover and Gay-Lussac, 188. Transition point, 172. Traube, preparation of semi-permeable membranes, 100. Tree, lead, 470. Triacid base, 211. Triads of Dobereiner, 136. Triazoic acid, methods of formation, 208. Tribasic acid, 212. Triphylite, 352. Trivalent, 134. Tungsten, 454. Tungsten, chlorides of, 455. Tungstic acid, 455. Tungstic acid, colloidal solution of, 455. Tungstic acids, poly-, 456. TurnbulPs blue, 428. Type metal, 470. Ultramarine, 415. Ultramarine, yellow, 450. Univalent, 134. Univalent ions, 361. Unsaturated solutions, 61. Uranates, 457. Uranic acids, 457. Uranite or pitchblende, 456. Uranium, 456. Uranium, chlorides of, 457. Uranium, oxides of, 456. Uranium radiation, 457. Uranium yellow, 457. Uranyl group, 457. Valence, variable, 406. Valency, 134. Valency, Faraday's law the basis of, 134 Valve, needle, 288. Vanadium, 270. 520 INDEX Van*! Hoff on osmotic preflsnre, 105. Vapor-densities, abnormal, 87. Vapor- denaitiea, abnormal, explanation of, 88. Vapor-density measurements, results of, 87. Vapor-density of sulphur, 174. Vaporization of water, heat of, M. Vapors, dissociation of, diminished by an excess of one of the products of dissociation, 91. Vapor-tension of water in its different states of aggregation, 58. Variable valence, 400. Vein mining, 474. Velocity of a reaction, 101. Verdigris, 405. Vermilion, 404. Victor Meyer, gas-di^lacement method of, 85. Victor Meyer, on the vapor-density of iodine, 101. Vinegar of lead, 483. Vitriol, blue, 404. Vitriol, green, 420. Volatile compound, whenever it can be formed it is formed, 191. Volhard^s method of determining silver, 474. Volume, critical, 284. Volume relations in which hydrogen and chlorine combine, 121. Volume relations in which hydrogen and oxygen combine, 30. Volumes, atomic, 145. Volumes, atomic, curve of, 140. Volumetric method, 474. Waage and Guldberg's law of mass action, 92. Waldeii*8 work on liquid sulphur di- oxide, 185. Wanklyn and Robinson's experiment, IK). AVater, analytical method of determin- ing the composition of, 51. Water and hydrogen dioxide, 40. Water and hydrogen dioxide, relations between, 07. Water m it oocurs in niUiire is imp 46. Water, a stable compound, 52. Water, boiling-point of, 54, 63. Water, composition of, 50. Water, conductivity of, 63. Water, dielectric constant of, 61. Water, dissociating power of, 63. Water, effervescent, 48. Water, electrolysis of, 50. Water, freezing of, 55. Water, freezing-point of, 63. Water-gas, 279, 292. Water-glass, 831. Water, heat of condensation of aU and solidification of, 56. Water, heat of vaporization, 54. Water, muddy, 48. Water, not an element, bat a o pound, 50. Water of crystallization, 46. Water of hydration, 46. Water, physical properties of, 54, 6< Water, properties affected by diasoi substances, 03. Water, purification of, 48. Waters, hard. 47, 371. Waters, mineral, 47. Water, solvent power of, 61. Water, specific heat of, 60. Water, specific inductive capacity 01. Waters, permanently hard, 372. Waters, temporarily hard, 371. Water, sulphur, 48. Water, superheating and supercool of, 50. Water, synthetical method of dei mining the composition of, 52. Water, temperature-pressure diagi of, 58. Water, vapor-tension of in its differ states of aggi'egation, 58. Weak acids and bases, explanation results with, 219. Weak acids and bases, neutralizat of, 219. Weight, increase of in combustion, Weights, law of combining, 11. INDEX 521 Welding of iron, 420. Weldon mud, 440. Weldon process for making chlorine, 110, 438. Welsbach light, 290. Weston cadmium element, 405. Wheatstone bridge, 113. White lead, 482. White, permanent, 380. Williamson^s electrochemical theory, 110. Winkler discovered ekasilicon — germa- nium, 149, 305. Witlierite, 378. W5hler, first prepared aluminium, 407. Wolframite, 455. WoUastonite, 374. Wood burns in oxygen, 16. Wood's fusible metal, 267. Wool, philosopher's, 388. Wroblewski and Olszewski, liquefaction of oxygen, 28. Wrought-iron, 421. Wulfenite, 453, 478. Xenon, 241. Yellow pruBsiate of potash, 427. Yellow ultramarine, 450. Yield of the reaction, 180. Ytterbium, 417. Yttrialite, 417. Yttrium, 417. Zeolites, 415. Zero absolute, can it be realized experi- mentally ?, 44. Zero absolute, of temperature, deter- mination of, 26. Zinc, 387. Zinc amalgam, 388. Zinc blende, 171, 387. Zinc dust, 387. Zinc, galvanized, 388. Zinc, granulated, 387. Zinc oxide and hydroxide, 388. Zinc precipitated by copper, 466. Zinc, salts of, 389^90. Zinc, use of in primary batteries, 391. Zinc white, 388. Zircon, 306. Zircon, compounds of, 306. Zirconium, 306. The Theory of Electrolytic Dissociation AND SOME OF ITS APPUCATIONS By HARRY C. JONES AssoctaU Pr<^essor in Physical Chemistry in tht Johns Hophins Univtrti^ Cloth. lamo. $1.60, net " I have tried several of the German works, small and large, and I have no hesitation in saying that Professor Jones's presentation is the simplest, clearest, and most adequate in any language." — Professor S. F. Barker, Johns Hopkins University. ''It is a text-book which will supply a long- felt want to teachers who have to do with students unfamiliar with the German language. 