CHAPTER IV.
THE VARIOUS STATES OF MATTER Sec.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.
Sec.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.
Sec.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.
Sec.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..