Treatise on heat / By the Rev. Dionysius Lardner.

  • Lardner, Dionysius, 1793-1859.
Date:
1833
Catalogue details

Licence: Public Domain Mark

Credit: Treatise on heat / By the Rev. Dionysius Lardner. Source: Wellcome Collection.

    155/446 (page 143)
    freezinii; point without solidifying. The same causes whicli produce the solidification of water also affect them in the same way, and they suddenly rise to the temperature at which they would naturally freeze ; the solidified parts giving out the latent heat, which takes a sensible form in raising the temperature of the whole mass to the freezing point. In reviewing what has been stateil in the pn'sent chapter, it will be perceived that the following general facts have been established, which form the liasis of all investigations concerning the phenomena of liquefaction and solidification : — I. Solid bodies, when raised to a certain temperature, pass into the liquiil form ; the same soliil always under- going this change at the same temperature. II. During the process of liijuefaction no elevation of temperature takes place, either in the solid or in the liipiid into which it is converted, though a considerable quantity of heat is imparted to the melting Iwdy. III. Different bodies undergo the process of liquefac- tion at different temperatures; and the temperature at which a solid liquefies is called its melting point, or its point of fusion. n’. Different solids absorb different quantities of heat in the process of liquefaction. Liquid bodies, when lowered to a certain temper- ature, pass into the solid form ; and the same liquid always passes into the solid form at the same temjier- ature. This temperature is called their freezing point. 'I'he freezing point of a liipiid is always the same as the melting point of the solid into which that liipiifl is converted by cold. VI. During the process of solidification, no fall of temperature takes place either in the liciuid or in the solid into which it is converted, though a considerable quantity of heat is dismissed in the process. ^ II. Different liijuids undergo the process of solidi- fication at different temperatures.