The New Physics and Its Evolution | Page 2

all the applications which belong to the domain
of Electrotechnics.
L. POINCARÉ.

Contents
EDITOR'S PREFATORY NOTE
AUTHOR'S PREFACE
TABLE OF CONTENTS

CHAPTER I
THE EVOLUTION OF PHYSICS
Revolutionary change in modern Physics only apparent: evolution not
revolution the rule in Physical Theory-- Revival of metaphysical

speculation and influence of Descartes: all phenomena reduced to
matter and movement-- Modern physicists challenge this: physical,
unlike mechanical, phenomena seldom reversible--Two schools, one
considering experimental laws imperative, the other merely studying
relations of magnitudes: both teach something of truth--Third or
eclectic school-- Is mechanics a branch of electrical science?

CHAPTER II
MEASUREMENTS
§ 1. Metrology: Lord Kelvin's view of its necessity-- Its definition
§ 2. The Measure of Length: Necessity for unit-- Absolute
length--History of Standard--Description of Standard Metre--Unit of
wave-lengths preferable--The International Metre
§ 3. The Measure of Mass: Distinction between mass and
weight--Objections to legal kilogramme and its precision--Possible
improvement
§ 4. The Measure of Time: Unit of time the second--Alternative units
proposed--Improvements in chronometry and invar
§ 5. The Measure of Temperature: Fundamental and derived
units--Ordinary unit of temperature purely arbitrary--Absolute unit
mass of H at pressure of 1 m. of Hg at 0° C.--Divergence of
thermometric and thermodynamic scales--Helium thermometer for low,
thermo-electric couple for high, temperatures--Lummer and
Pringsheim's improvements in thermometry.
§ 6. Derived Units and Measure of Energy: Importance of erg as
unit--Calorimeter usual means of determination--Photometric units.
§ 7. Measure of Physical Constants: Constant of
gravitation--Discoveries of Cavendish, Vernon Boys, Eötvös, Richarz

and Krigar-Menzel--Michelson's improvements on Fizeau and
Foucault's experiments-- Measure of speed of light.

CHAPTER III
PRINCIPLES
§ 1. The Principles of Physics: The Principles of Mechanics affected by
recent discoveries--Is mass indestructible?--Landolt and Heydweiller's
experiments --Lavoisier's law only approximately true--Curie's
principle of symmetry.
§ 2. The Principle of the Conservation of Energy: Its evolution:
Bernoulli, Lavoisier and Laplace, Young, Rumford, Davy, Sadi Carnot,
and Robert Mayer--Mayer's drawbacks--Error of those who would
make mechanics part of energetics--Verdet's predictions--Rankine
inventor of energetics--Usefulness of Work as standard form of
energy--Physicists who think matter form of energy-- Objections to
this--Philosophical value of conservation doctrine.
§ 3. The Principle of Carnot and Clausius: Originality of Carnot's
principle that fall of temperature necessary for production of work by
heat-- Clausius' postulate that heat cannot pass from cold to hot body
without accessory phenomena--Entropy result of this--Definition of
entropy--Entropy tends to increase incessantly--A magnitude which
measures evolution of system--Clausius' and Kelvin's deduction that
heat end of all energy in Universe--Objection to this-- Carnot's
principle not necessarily referable to mechanics --Brownian
movements--Lippmann's objection to kinetic hypothesis.
§ 4. Thermodynamics: Historical work of Massieu, Willard Gibbs,
Helmholtz, and Duhem--Willard Gibbs founder of thermodynamic
statics, Van t'Hoff its reviver--The Phase Law--Raveau explains it
without thermodynamics.
§ 5. Atomism: Connection of subject with preceding Hannequin's essay

on the atomic hypothesis--Molecular physics in
disfavour--Surface-tension, etc., vanishes when molecule reached--Size
of molecule--Kinetic theory of gases--Willard Gibbs and Boltzmann
introduce into it law of probabilities--Mean free path of gaseous
molecules--Application to optics--Final division of matter.

CHAPTER IV
THE VARIOUS STATES OF MATTER
§ 1. The Statics of Fluids: Researches of Andrews, Cailletet, and others
on liquid and gaseous states-- Amagat's experiments--Van der Waals'
equation--Discovery of corresponding states--Amagat's superposed
diagrams--Exceptions to law--Statics of mixed fluids-- Kamerlingh
Onnes' researches--Critical Constants-- Characteristic equation of fluid
not yet ascertainable.
§ 2. The Liquefaction of Gases and Low Temperatures: Linde's,
Siemens', and Claude's methods of liquefying gases--Apparatus of
Claude described--Dewar's experiments--Modification of electrical
properties of matter by extreme cold: of magnetic and chemical--
Vitality of bacteria unaltered--Ramsay's discovery of rare gases of
atmosphere--Their distribution in nature--Liquid hydrogen--Helium.
§ 3. Solids and Liquids: Continuity of Solid and Liquid
States--Viscosity common to both--Also Rigidity-- Spring's analogies
of solids and liquids--Crystallization --Lehmann's liquid crystals--Their
existence doubted --Tamman's view of discontinuity between
crystalline and liquid states.
§ 4. The Deformation of Solids: Elasticity-- Hoocke's, Bach's, and
Bouasse's researches--Voigt on the elasticity of crystals--Elastic and
permanent deformations--Brillouin's states of unstable
equilibria--Duhem and the thermodynamic postulates-- Experimental
confirmation--Guillaume's researches on nickel steel--Alloys.

CHAPTER V
SOLUTIONS AND ELECTROLYTIC DISSOCIATION
§ 1. Solution: Kirchhoff's, Gibb's, Duhem's and Van t'Hoff's researches.
§ 2. Osmosis: History of phenomenon--Traube and biologists establish
existence of semi-permeable walls--Villard's experiments with
gases--Pfeffer shows osmotic pressure proportional to concentration--
Disagreement as to cause of phenomenon.
§ 3. Osmosis applied to Solution: Van t'Hoff's discoveries--Analogy
between dissolved body and perfect gas--Faults in analogy.
§ 4. Electrolytic Dissociation: Van t'Hoff's and Arrhenius'
researches--Ionic hypothesis of--Fierce opposition to at
first--Arrhenius' ideas now triumphant --Advantages of Arrhenius'
hypothesis--"The ions which react"--Ostwald's conclusions from
this--Nernst's theory of Electrolysis--Electrolysis of gases makes
electronic theory probable--Faraday's two laws--Valency-- Helmholtz's
consequences from Faraday's laws.

CHAPTER VI
THE ETHER
§ 1. The Luminiferous Ether: First idea of Ether due to
Descartes--Ether must be imponderable--Fresnel shows light vibrations
to be transverse--Transverse vibrations cannot exist in fluid--Ether
must