CHAP. VII.—ON CAPILLARY PHENOMENA

P. 174

Form of Capillary Surface-Heights of the Column-Attractions and
Repulsions-Forces of Capillarity-Equilibrium of the Column—
General Observations-Absorption and Filtration.. Arts. 111–118

CHAP. VIII-ON ACOUSTICS, OR THE LAWS OF SOUND

SECTION 1.

Object of Acoustics-Sound a motion of Vibration-Transmission of
Sound—Waves of Sound-Decay of Sound-Velocity of Sound
-Rays of Sound—Reflexion of Sound-Echo-Speaking Trum-
pets-Thunder-the Ear
Arts. 119-130

SECTION II.

Musical Sounds-Tones-Laws of Vibratory Strings-Unison—Con-
cords and Discords—Musical Scale—Beats—Musical Instruments

Preliminary Observations — Temperature — Thermometers — Common
Mercurial Thermometer-Graduation-Construction of the Ther-
mometer-Dilatation of Solids-Compensation Pendulum—Bre-
quet's Thermometer-Pyrometers—Illustrations .. Arts. 140—149

SECTION II.

Change of State-Fluidity the consequence of Heat-Conditions of
Fusion-Latent Heat-Solidification-Freezing Mixtures-For-
mation of Vapour-Elastic or High Pressure Steam—Principle of
the Steam Engine-Evaporation—the Air impedes Evaporation—
Quantity of Vapour depends on the Temperature—Maximum
Tension of Vapour-Evaporation stopped by the pressure of the
Vapour-Condensation of Vapour-Liquefaction of Gases-Cold
produced by Evaporation...
Arts. 150-164

SECTION III.

Transfer of Heat-Radiation-Differential Thermometer-Absorbing
Power—Safety Lamp—Reflecting Power-Equilibrium of Tem-
perature-Apparent Reflexion and Radiation of Cold-Cold of
Clear Nights-Deposition of Dew-Laws of Cooling

Arts. 165-176

SECTION IV.

Specific Heat-Calorimeter-Method of Mixtures-Specific Heat of
Arts. 177-182

Gases-Consequences

SECTION V.

Sources of Heat-the Sun-Central Heat of the Earth-Animal
Heat-Development of Heat by Mechanical Means-Chemical
Combinations-Theories of Heat

CHAP. X.-ON LIGHT...

SECTION I.

Arts. 183-189

General Properties of Light-Direction of Propagation-Rays and
Pencils of Light-Intensity as inverse square-Opaque Bodies-
Image of Sun always round-Velocity of Light-Aberration
Arts. 190-198

....

SECTION II.

Reflexion at a Plane Surface-Formation of Images-Reflexion at two
Plane Mirrors-Reflexion of Curved Mirrors-Spherical Mirror-
Formation of Images by Spherical Mirrors

...... Arts. 199-206

SECTION III.

Refraction of Light-Critical Angle-Unusual Refraction-Mirage..

Arts. 207-210

SECTION IV.

Prisms-Phenomena of Prisms-Direction and Emergence of the Rays
-Deviation-Camera Lucida-Lenses-Formation of Images-
... Arts. 211-219

Magic Lantern

SECTION V.

Decomposition and Constitution of Light-Refrangibilities. of the
Rays-Composition of the Spectrum-Colours of the Spectrum
all simple-Recomposition of Light-Complementary Colours-
the Rainbow-Lines in the Spectrum-Measure of the Refrangi-
bilities of different rays — Irrationality of Dispersion — Achro-
matism-Peculiar Properties of the Rays of the Spectrum

-

......

Arts. 220-231

SECTION VI.

Laws of Vision-the Eye- Formation of an Image - Defects of
Vision-Spectacles-Microscopes...
Arts. 232-237

SECTION VII.

Diffraction of Light-Phenomena of Diffraction-Fresnel's Experi-
ment-Principle of Interferences-Formation of coloured Rings in
thin plates Breadth of the Rings-Fits of Transmission and Re-
flexion...
Arts. 238-246

SECTION VIII.

Phenomena of Double Refraction-Laws of the Ordinary and Extra-
ordinary Ray-Properties of the Rays-Polarization-Polariza-
tion by Reflexion..
Arts. 247-251

SECTION IX.

The Undulatory Theory-Nature of Light-Interference an immedi-
ate consequence of the theory of Undulations-Theory of Re-
flexion and Refraction.....

CHAP. XI.-ON ELECTRICITY AND MAGNETISM

SECTION I.

Arts. 252-255

⚫p. 383

Electricity-Phenomena of Electricity-Electroscopes - Conducting
and Non-Conducting or Insulating Bodies Two kinds of Elec-
tricity-Natural state of Bodies-Communication of Electricity—
Electricity by Influence or Induction-Return Stroke-Electricity
of Bodies communicating with the Earth-the Electrophorus—
Dissipation of Electricity-Leyden Jar-Electric Light—Motion
of Electrized Bodies
Arts. 256-271

SECTION II.

Galvanism, or Voltaic Electricity-Electromotive Force-Construc-
tion of the Voltaic Pile-the Insulated Pile-Forces of a Pile-
Various kinds of Piles-Effects of the Pile ... Arts. 272-279

SECTION III.

......

Magnetism-Neutral Plane-Poles-Attraction and Repulsion of Poles
-Magnetic Fluid-Iron and Steel rendered Magnetic-Magnetic
Action of the Earth-Definition of Terms-Points of application of
the Magnetic Force of the Earth-Perturbations and Diurnal
Oscillations-Magnetic Intensity of the Earth-Earth's Action on
soft Iron-Coercive Force-Iron of Vessels...... Arts. 280-294

SECTION IV.

Electro-magnetism-Discovery of the Science-Definitions-Effect of
the Force-Character of the Force-Law of the Force-Theory
of Currents-Equilibrium of a Needle subject to a Current-
Electro-magnetic Multiplier-Magnetization by Electric Current
-Rotation of Magnets-Thermo-Electricity . Arts. 295-306

SECTION V.

Atmospheric Electricity-Lightning-Effects of Lightning-Sources
of Atmospheric Electricity-Lightning Rods-Aurora Borealis..
Arts. 307-314

CHAP. XII-CONCLUSION..

......

⚫p. 483

Arts. 315-319

Theory of Gravitation-Theory of Heat-Theory of Light-Theory of
Electricity and Magnetism-Conclusion

THE

ELEMENTS OF PHYSICS.

CHAP. I.

INTRODUCTION-LAWS OF NATURE-PHYSICAL THEORIESPRELIMINARY NOTIONS.

1. THE circle of the natural sciences presents so vast a field of inquiry, that the limited faculties of man are rarely sufficient to embrace its whole extent. The richness of the subject demands some division of labour by which each one may according to natural inclination and opportunity assist in the advance of human knowledge; hence have arisen so many various departments in the study of nature, on the peculiar objects of some of which it may be well to premise a few observations.

The distinction which exists between an internal and an external world, that is, between the world of mind and the world of matter, will be readily recognised. Each has its peculiar department, and the internal world, or world of mind, gives rise to mental philosophy, which must never be confounded with any other branch of study, and is wholly employed in tracing the origin and succession of all those phenomena which are purely mental.

The external world may be at once divided into animate and inanimate nature. The sciences which treat of ani

B