136 Review of the Controversy Regarding the Motion of Glaciers. 



Avhile a molecule of ice is in the act of transmitting the energy 

 received (say, from a fire) it loses for the moment its shearing force, if 

 the temperature of the ice be not under 32° Fah. If we apply heat to the 

 end of a bar of iron, the molecules at the surface of the end have their 

 temperature raised. Molecule A, at the surface, whose temperature has 

 been raised, instantly commences to transfer to 5 a portion of the 

 energy received. The tendency of this i^rocess is to lower the tem- 

 perature of J. and to raise that of J5. B, then, Avith its temperature raised, 

 begins to transfer the energy to C The result is then the same. B 

 tends to fall in temperature and C to rise. This process goes on from 

 molecule to molecule, until the opposite end of the bar is reached. 

 Here, in this case, the energy or heat applied to the end of the bar is 

 transmitted from molecule to molecule, under the form of heat or tem- 

 jjerature. The energy applied to the bar does 7iot change its character, 

 it posses right along from molecule to molecule, under the form of heat or 

 te)nperature. But the nature of the process must be wholly different 

 if the transferrence takes place through a bar of ice at the temperature 

 of 32°. Suppose we apply the heat of the fire to the end of a bar of 

 ice at 32°, the molecules of the ice can not possibly have their tem- 

 peratures raised in the least degree. How, then, can molecule A take 

 in, under the form of heat, the energy received from the fire without 

 being heated or having its temperature raised? The thing is imposs- 

 ible. The energy of the fire must appear in A under a different form 

 from that of heat. The same process of reasoning is equally ajDplicable 

 to B ; the molecule B can not 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 v/e reach the 

 ()j)posite end of the bar of ice. And yet, strange to say, the last mole- 

 cule transmits in the form of heat its energy to the objects beyond ; 

 for we find that the heat applied on one side of a piece of ice will 

 affect the thermal pile on the other. 



"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 which bind the atoms or particles together into the 

 crystalline form. The energy, then, must exist in the dissolved crys- 

 talline molecule under the statical form of an affinity — crystalline affin- 

 ity — or whatever else Ave may call it. That is to say, the energy then 

 exists in the particles as a poAver or tendency to rush together again 

 into the crystalline form, and the moment they are alloAved to do so 

 they give out the energy that Avas exi^ended upon them in their 

 separation. This energy, Avhen it is given out, again assumes the 



