﻿of the Motion of Glaciers. 203 



of heat, the energy received from the fire without being heated 

 or having its temperature raised ? The thing is impossible. The 

 energy of the fire must appear in A under a different form from 

 that of heat. The same process of reasoning is equally applicable 

 to B. The molecule B cannot accept of the energy from A under 

 the form of heat; it must receive it under some other form. 

 The same must hold equally true of all the other molecules 

 till we reach the opposite end of the bar of ice. And yet, 

 strange to say, the last molecule transmits in the form of heat 

 its energy to the objects beyond ; for we find that the heat ap- 

 plied to one side of a piece of ice will affect the thermal pile on 

 the opposite side. 



The question is susceptible of a clear and definite answer. 

 When heat is applied to a molecule of ice at 32°, the heat applied 

 does not raise the temperature of the molecule, it is consumed 

 in work against the cohesive forces binding the atoms or par- 

 ticles together into the crystalline form. The energy then must 

 exist in the dissolved crystalline molecule, under the statical 

 form of an affinity — crystalline affinity, or whatever else we may 

 call it. That is to say, the energy then exists in the particles as 

 a power or tendency to rush together again into the crystalline 

 form, and the moment they are allowed to do so they give out 

 the energy that was expended upon them in their separation. 

 This energy, when it is thus given out again, assumes the dyna- 

 mical form of heat; in other words, the molecule gives out heat 

 in the act of freezing. The heat thus given out may be employed 

 to melt the next adjoining molecule. The ice- molecules take on 

 energy from a heated body by melting. That peculiar form of 

 motion or energy called heat disappears in forcing the particles 

 of the crystalline molecule separate, and for the time being exists 

 in the form of a tendency in the separated particles to come 

 together again into the crystalline form. 



But it must be observed that although the crystalline molecule, 

 when it is acting as a conductor, takes on energy under this form 

 from the heated body, it only exists in the molecule under such 

 a form during the moment of transmission ; that is to say, the 

 molecule is melted, but only for the moment. When B accepts 

 of the energy from A, the molecule A instantly assumes the 

 crystalline form. B is now melted ; and when C accepts of the 

 energy from B, then B also in turn assumes the solid state. This 

 process goes on from molecule to molecule till the energy is 

 transmitted through to the opposite side and the ice is left in its 

 original solid state. This is the rationale of Faraday's property 

 of regelation. 



This is no mere theory or hypothesis ; it is a necessary conse- 

 quence from known facts. We know that ice at 32° cannot take 



