Elements of chemistry : theoretical and practical

Part I. Chemical Physics

LONDON:

JOHN W. PARKER AND SON, WEST STRAND.

LONDON:

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ADVERTISEMENT

TO THE FIRST EDITION.

HE work, of which the First Part is now presented to the Reader, was originally designed to supply the Students who were attending the Course of Lectures on Chemistry at King’s College with a text-book to guide them in their studies.

The present Part, on Chemical Physics^ is devoted to a subject upon which no elementary work has appeared in this country since the publication of the excellent Treatise of the late Professor Daniell, and in attempting to supply what the author, in his own experience, has felt to be a want, he ventures to hope that the result of his labours may be found useful to persons beyond the circle of his own immediate Class. Much new matter, which has never yet been reduced to a systematic form, is now presented to the Student, particularly in the chapters on Adhesion^ on Heat^ and on Voltaic Electricity.

It is proposed to complete the work in Three Parts. The Second Part, which will be devoted to Inorganic Chemistry., is expected to be ready by the end of the present year ; and the Third Part, which will embrace Organic Chemistry., in the spring of next year.

As the author was originally a pupil of Professor Daniell, and was subsequently, for several years, associated with him as Lecturer on Chemistry, it has happened that in some of the subjects treated of in this volume, the

IV advertisement to the first edition.

thoughts and mode of arraugement resemble those adopted by that distinguished philosopher in his Introduction to the Study of Chemical Philosophy.

The second edition of that work was published so far back as 1843; and even if the work itself had not been long out of print, the progress of science would have detracted greatly from its utility as a text-book. The adaptation of that work to the systematic teaching of the present day would have involved changes of an extensive character : moreover, every teacher who takes an interest in the progress of his class has his own views and methods. The Author, therefore, judged it better, after much consideration, to bring out a new work, leaving untouclied that of his late Master as the true exponent of his views upon some of those branches of science which his researches had contributed to advance and adorn.

The Author cannot omit to avail himself of the present opportunity of expressing his obligations to his friend, Mr. C. Tomlinson, for many valuable suggestions, and for the warm interest which he has taken in the progress of the work, but more especially for the devotion of no inconsiderable portion of time and labour to the revision of the proof sheets.

King’s College, London, March, 1855.

ADVERTISEMENT

TO THE SECOND EDITION.

URTNG the five years which have elapsed since the publication of the First Part of this work, many advances have been made in the branches of Physics of which it treats ; and it has been the Author’s aim, in preparing a new edition, to include the more important points of recent discovery. A few of these additions may here be mentioned.

In the section on Adhesion are various new details on osmosis and on the solubility and absorption of gases. In the chapter on Crystallization will be found a notice of Pasteur’s researches on the causes which modify crystalline form ; in that on light, Becquerel’s experiments on phosphorescence, and Gladstone and Dale’s on dispersion, are given. In that on Heat, some account of the mechanical theory of heat; of Deville and Troost’s experiments on vapour densities at very high temperatures ; of various researches on conducting power, as well as on the phenomena of freezing, are added ; besides a notice of Regnault’s results on the specific heat of gases. In the chapter on Electricity will be found a fuller development of the theory of the Leyden jar and of the Electrophorus ; various researches on the electric conductivity of metals ; fuller details respecting the use of RuhmkorfF’s coil, and the varieties of electric discharge in rarefied media, and in exhausted tubes. In addition to these, further information is giveiA

VI

ADVERTISEMENT TO THE SECOND EDITION.

respecting the phenomena of induced currents; of magnetic polarization of light, and an abstract of Tyndall’s researches on diamagnetic polarity.

The whole work, indeed, has been carefully revised throughout, with a view of rendering it more worthy of confidence as a book of reference, and as a succinct statement of the present condition of our knowledge upon the points of which it treats.

In addition to the kindness of friends formerly acknowledged, the Author has to offer his thanks to his friend, Mr. E. A. Hadow, of King’s College, who has afforded material assistance in revising the proof sheets of the present volume.

King's College, London, MarcH, i860.

Chapter I

NO. OP

PABAGBAPH. PAGE

Preliminary View of Chemical Affinity — Laws of Combination i — 26

1 Chemical Distinction of Bodies into Elements and Compounds

2 Differences between Physical and Chemical Properties .

3 Physical States of Matter

4 Porosity

4 a Divisibility of Matter

5 Varieties of Attraction

6 General Characters of Acids, Alkalies, and Salts

7 Chaiuctei’s of Chemical Affinity

8 Laws of Combination .

9 Law of Definite Proportions

I o Law of Multiple Proportions

I I Law of Equivalent Proportions

12 Tables of Equivalent Numbers

13 Application of the Law of Equivalent Proportions . . . .

1 4 Law of V olumes

15 Symbolic Notation

5 5 /

CHAPTER II. ‘ Weights and Measures — Specific Gravity . . 26 — 35

16 English System of Weights and Measures 26

1 7 French System of W eights and Measures 27

18 The Balance ’ 28

19 Specific Gravity - ^9

20 Specific Gravity of Liquids

21 Specific Gravity of Solids 3’'^

22 The Hydrometer 33

23 Correction for Weighings taken in Air 34

Vlll

TATsLE OF CONTENTS.

Chapter III

IfO. OP

PABAGIlApn. PAGE

On some Varieties of Molecular Force. . . 35 — 123

24 Varieties of Molecular Force 35

§ I. Elasticity 35 — 54

25 Elasticity of Solids and Liquids 35

26 Boyle’s or Marriotte’s Law of Elasticity in Gases 37

27 Repulsion among tlie particles of Gases 38

28 The Air-Pump 39

29 Air-Pump with a Single Barrel 40

30 Elasticity of the Air 41

3 X The Condensing Syringe 41

32 Weight of the Air 42

33 The Household Pump . . . 43

34 The Barometer and Pi’essure Gauge 44

35 The Syphon 46

36 Downward Pressure of the Atmosphere 47

37 The Pneumatic Trough 48

38 The Gas Holder 49

39 The Mercurial Trough 50

40 Correction of Gases for Pressure 50

41 Density of the Atmosphere at different heights 52

§ II. Cohesion . 54 — 58

42 Measurement of Cohesion 54

43 Reunion of Divided Surfaces 54

44 Cohesion of Solids 25

45 Cohesion of Liquids 56

46 Influence of Heat on Cohesion 57

§ III. Adhesion — Diffusion of Liquids and Gases 58 — 96

47 Adhesion 8

48 Cements

49 Capillary Action 61

50 Variation in degree of Capillary Action of Liquids . . . . 62

TABLE OF CONTENTS. ix

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PABAGBAPH. PAGE

51 Capillary Depression of Mercuiy 63

52 Extensive Operation of Capillary Actions 64

53 Influence of Surface on Adhesion • • 65

55 Adhesion between Liquids 69

56 Difiusion of Liquids — Mode of measuring it 7°

57 Laws of the Difiiision of Liquids- . .- 7^

58 Endosmosis and Exosmosis 74

59 The Osmometer — Conditions of Osmose 75

60 Flow of Liquids through Capillary tubes 7^

61 Adhesion of Gases to Liquids — Solubility of Gases . . . . 81

62 Adhesion of Gases to Solids 83

63 Desiccation of Gases 85

64 Difiusion of Gases • 86

65 Effusion of Gases 89

66 Transpiration of Gases 90

67 Passage of Gases through Diaphragms • 93

68 Separation of Bodies by Cold or Heat • 95

§ lY. Crystallization ; . • . . . . 96 — 123

69 Modes of obtaining Crystals 96

70 Separation of Salts by the process of Crystallization .... 98

71 Sudden Crystallization — Nuclei 99

72 Circumstances which modify Crystalline Form 99

73 Change of Bulk in the act of Solidification 101

74 Development of Crystalline Form in Solids 102

7 5 Structure of Crystals — Cleavage 103

76 Goniometers 105

77 The Reflecting Goniometer . . . . . 105

78 Symmetry of Crystalline Form 107

79 Classification of Crystals 109

80 Isomorphism 115

81 Chemical bearings of Isomorphism 117

82 Isomorphous Groups 118

83 Dimorphism • 119

84 Allotropy 120

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TABLE or CONTENTS.

Chapter IV

NO. OP

PABAOBAPn. PACE

85 Influence of Light in producing Chemical Changes . . . .123

86 Sources of Light 124

87 Theories of Light — Undulations 126

88 Illustration of Undulations from Sound 126

89 Varieties of Sound 128

90 Mechanism of Undulation 129

91 Transparency and Opacity 130

92 Law of the Diminution of Light by Distance 13 1

93 Rum ford’s Photometer 132

94 Reflection from Plane Surfaces 133

95 Reflection from Curved Surfaces 134

96 Refraction 135

97 Law of the Sines 136

98 Refraction at Inclined Surfaces 137

99 Total Reflection 138

100 Wollaston’s Method of ascertaining Refractive Power . . .139

1 01 Prismatic Analysis of Light 141

102 Theory of Colours — Absorption — Dispersion 142

103 Fixed Lines in the Spectrum 146

104 Change in the Refrangibility of Light 147

105 Complex Nature of Radiant Force 150

1 06 Phosphorogenic Rays — Phosphoroscope 150

107 Velocity of Light — Its Measurement 154

108 Frequency of Undulation in Difierent Colours 155

109 Interference 155

no Colours of thin Plates 158

111 Double Refraction 160

1 12 Influence of Crystalline Form on Double Refraction . . . .162

1 13 Polarization of Light by Double Refr'action 162

T14 Polarization by Reflection 164

1 15 Distinction between Common and Polai’ized Light . . . . t66

1 16 Polarization by Reflection from a Bundle of Plates . . . .167

1 17 Bfiect of the Analyser in rotating the Plane of Polarization . 167

1 18 Colours of Polarized Light 168

1 19 Colours in Plates cut perpendicular to the Axis 168

TABLE OF CONTENTS. XI

NO. OP

PAKA.GKAPII. PAGE

1 20 Coloured Circular Polarization 171

12 1 Magnetic Polarization i73

CHAPTER V. 122 General Properties of Heat i74

123 Sources of Heat i75

124 Nature of Heat — Mechanical Theoiy of Heat T78

§ I. Expansion — Measurement of Temperature 180 — 204

125 Difference between Heat and Temperature 180

126 Expansion of Solids 181

127 Expansion of Liquids 183

128 Expansion of Gases 186

129 Air Thermometers 186

130 Principle on which the Thermometer is Graduated . . . .188

131 Tests of a good Thermometer 189

132 Different Forms of Thermometer 190

T33 Increase in the Ratio of Dilatation with Rise of Temperature . 19 1

134 Pyrometers 192

135 Comparative Range of Temperature 194

136 Force exerted by Expansion ..194

137 Anomalous Expansion of Water 195

138 Correction of Gases for Temperature 196

139 Adjustment of Bulk to Changes of Temperature 197

140 Process of taking Specific Gravity of Gases 197

141 Determination of the Specific Gravity of Vapour 200

§ II. On the Equilibrium of Temperature 204 — 230

142 Equilibrium of Temperature 204

144 Inequality in the Rate of Conduction in different Directions . 208

145 Convection of Heat 210

146 Currents in Gases ; — Ventilation 211

147 Trade Winds — Land and Sea-breezes 213

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TABLE OF CONTEXTS.

NO. OP PAllAOBAPn.

148 Gulf Stream

149 Eadiation of Heat . , .

150 Reflection of Heat

15 1 Absorption of Heat

152 Connexion between Absorjition and Radiation

153 Formation of Dew

154 Law of Cooling by Radiation

155 E-elative Absorbability of difierent kinds of Heat . . . .

156 Transmission of Heat through Screens

157 Refraction of Heat

158 Probable Independence of Light and Heat

159 Double Refraction and Polarization of Heat

PIGS

. 214

• 215

• 230

§ III. Heat of Comj)osition . . , 230 — 287

160 Specific Heat

1 6 1 Variation in Amount of Specific Heat according to Physical State 23 4

162 Disappearance of Heat during Liquefaction 236

163 Freezing Mixtures

163 a Regelation of Ice _

164 Evolution of Heat During Solidification 242

163 Disappearance of Heat during the Formation of Vapour , . 243 166 Ebullition

16’j Influence of Adhesion on the Boiling Point 246

168 Influence of Solids in Solution upon the Boiling Point . . .247

169 Influence of Pressure on the Boiling Point 248

170 Measurement of Heights by the Boiling Point 249

17 1 High Pressure Steam ...

172 Production of Cold during Evaporation 252

173 Measurement of the Latent Heat of Vapours 253

174 Economical Applications of Steam 255

175 Distillation . . .

176 EvajDoration

177 Dalton’s Law of the Tension of Vapoui's 26^;

178 Limit of Evaporation 267

179 Circumstances which influence the Rate of Evaporation . . . 268

180 Dew Point .....

181 Daniell’s Hygrometer .,^2

J 8 1 a Wet Bulb Hygrometer

TABLE OF CONTENTS. xiii

mo. OP

PAKAGKAPn. PAGK

183 Spheroidal State produced by Heat 284

CHAPTER VI. Electricity and Magnetism 287 — 472

184 Connexion of Electricity with Magnetism

. 287

§ I. Magnetism

185 Leading Characters of Magnetic Action

186 Magnetic Induction

187 Preparation of Magnets

188 Influence of Molecular Actions on Magnetism .

189 Measurement of the Magnetic Intensity of a Bar . .

190 Magnetism of the Earth : — The Dip

191 Declination or Valuation

192 Variation in the Intensity of the Earth’s Magnetism

288 — 298

. . 288

. . . 289

. . 292

• .293

. . .294

. . .294

. . . 295

. . . 296

§ II. Static Electricity .

T93 Simple Facts connected with Electricity

T94 Two Kinds of Electricity

193 Insulators and Conductors ....

196 Electroscopes

197 Electrical Hypotheses

198 Electrical Induction

199 Faraday’s Theory of Induction .' .

200 Distribution of the Electric Charge .

201 Electi’ical Machines

202 Further Illustrations of Induction

203 The Electrophorus

204 Spread of Induction

205 The Leyden Jar

206 Measures of Electricity

207 Specific Induction

208 Various Modes of Discharge .

209 a Development of Heat . . . . .

210 Disruptive Discharge

. . . . 398—344

• 3^7

MV

TABLE OF CONTENTS.

rAUAGiupii. ricz'

21 1 Velocity of Dischai'gc 33°

2 12 Striking Distance 33^

213 Convection 335

214 Other Sources of Electricity — Heat — Fracture 336

214 a Electricity from Chemical Action 338

215 Electricity of Vapour 338

216 Atmosphei’ic Electricity — Lightning rods 339

217 Aurora Borealis 343

§ III. Galvanic or Voltaic Electricity 344 — 413

218 Gal vani’s Discovery 344

219 Simple Voltaic Circuits 345

220 Activity of the Conducting Wire 346

221 Action of the Conducting Wire on a Magnetic Xeedle . . . 347

222 The Galvanometer 348

223 Summary of the Effects produced by the Conducting Wire . 350

224 The Voltaic Pile : — the Crown of Cups 350

225 Electric Disturbance produced by Contact 352

226 Necessity of Chemical Action to jjroduce Voltaic Action . . 352

227 Polarization and Transfer of the Elements of the Liquid . . 353

228 Energy of the Current proportionate to the Chemical Activity. 356

229 Direction of the Current dependent on the Direction of the

Chemical Action : — Protection of Ships’ Sheathing . . .357

230 Circuits with One Metal and Two Liquids 362

230 a General Summary ^6-

231 Counteracting Currents : — Grove’s Gas Batteiy 365

232 Daniell’s Battery ..368

233 Grove’s Nitric Acid Battery — Bunsen’s Coke Battery . . .370

234 Smee’s Battery 2^2

235 Resistances to the Voltaic Current 373

236 Differences between a Simple and a Compound Circuit . . .375

237 Ohm’s Formulae ^78

238 Chemical Decomposition . • ^8o

238 a The Voltameter ^Si

239 Further Application of Ohm’s Formulae 383

240 Wheatstone’s Rheostat and Resistance Coils 385

241 Processes of Voltaic Discharge 388

242 Conduction — Conducting Power of Solids 38S

TABLE OF CONTENTS. XV

yo. OP

FABAGBAFH. FAGB

243 Conduction by Liquids 395

244 Conducting Power of Gases 397

245 Disruptive Discharge : — Electric Light 397

246 Discharge by Convection : — Chemical Actions 403

247 Laws of Electrolysis 404

248 Relative Decomposability of Electrolytes 407

249 Resemblances between Static and Voltaic Electricity . . .408

250 Deluc’s Dry Pile — Zamboni’s Pile . ......... 410

251 Water Battery 411

§ IV. Electro-Magnetism .... 413 — 431

252 Law of Electro-Magnetic Action ; — Tangent Galvanometer . 413

253 Influence of a Conducting Wire in exciting Magnetism . .415

254 Formation of Electro-Magnets 415

255 Molecular Movements during the Magnetization of Bars . .417

256 Laws of Electro-Magnetism 417

257 Ampere’s Theory of Electro-Magnetism 419

258 Mutual Influence of Wires which are conveying Currents . . 420

259 Electro-Magnetic Rotations . 422

260 Electric Telegraph 425

§ V. Magneto-Electricity .... 431 — 447

261 Volta-Electric Induction 431

262 Magneto-Electric Induction 432

263 RuhmkorfTs Magneto-Electric Induction Coil — Stratified Elec-

tric Discharge 433

263 a Inductive Action of Currents ; — Henry’s Coils 439

264 Arago’s Rotations 442

265 Magneto-Electric Machines 444

§ VI. Thermo-Electricity .... 447 — 45^

266 Summary of Facta in Thermo-Electricity 447

267 Thermo-Multiplier 45°

268 Reduction of Temperature by the Electric Current . . . .452

XVI

TABLE OF CONTEXTS.

NO. or paob

PiBAGBAPn.

§ VII. Animal Electricity .... 45^ — 455

269 Electrical Phenomena exhibited by the Torpedo 45 2

270 Electiical Phenomena of the Gymnotus 453

271 The Muscular Current in Living Animals 454

§ VIII. ilelations of Light and Magnetism ;

— Diamagnetism 455 — 47 2

272 Magnetic Polarization of Light 455

273 Magnetism of Bodies in general 45^

274 Diamagnetism 459

275 Diamagnetism of Gases 4^°

276 List of Magnetic and Diamagnetic Bodies 4^2

277 Influence of Chemical Composition upon the Magnetic or Dia-

magnetic State 463

278 Influence of Structure on Diamagnetism 464

279 Law of Diamagnetic Repulsion 4^6

,280 Mutual Relations of Different kinds of Force 467

EREATA.

Page 89, 9 lines from tlie top, for weights, read volumes. » 3*9> 2 ,, bottom, ,, caJce ,, jar.

ELEMENTS OF CHEMISTRY

PART I.

CHEMICAL PHYSICS.