54 NOTE ON REGELATION. 
“NOTE ON REGELATION.” 
BY MICHAEL FARADAY, D.C.L., F.R.S., ETC. 
[From the Proceedings of the Royal Society: Read April 26th, 1860.] 
The philosophy of the phenomenon now understood by the word 
Regelation is exceedingly interesting, not only because of its relation 
to glacial action under natural circumstances, as shown by Tyndall 
and others, but also, and as I think especially, in its bearmgs upon 
molecular action; and this is shown, not merely by the desire of 
different philosophers to assign the true physical principle of action, 
but also by the great differences between the views which they have 
taken. 
Two pieces of thawing ice, if put together, adhere and become 
one; at a place where liquefaction was proceeding, congelation sud- 
denly occurs. The effect will take place in air, or in water, or im 
vacuo. It will occur at every point where the two pieces of ice touch; 
but not with ice below the freezing point, 7. e. with dry ice, or ice so 
cold as to be everywhere in the solid state. 
Three different views are taken of the nature of this <c 
When first observed in 1850, I explained it by supposing that a 
particle of water, which could retain the liquid state whilst touching 
ice only on one side, could not retain the liquid state if it were 
touched by ice on both sides; but became solid, the general tem- 
perature ramaining the same.* Professor J. Thompson, who dis- 
covered that pressure lowered the freezing-point of water,} attributed 
the regelation to the fact that two pieces of ice could not be made 
to bear on each other without pressure; and that the pressure, how- 
ever slight, would cause fusion at the place where the particles 
touched, accompanied by relief of the pressure and resolidification of 
the water at the place of contact, in the manner that he has fully 
explained in a recent communication to the Royal Societyt. Profes- 
sor Forbes assents to neither of these views ; but admitting Person’s 
idea of the gradual liquefaction of ice, and assuming that ice is 
essentially colder than ice-cold water, 7. e. the water in contact with 
* Researches in Chemistry and Physics, 8vo, pp. 373, 378. 
+ Mousson says that a pressure of 13,000 atmospheres lowers the temperature of freezing 
from 60° to —18° Cent, 
t Royal Society Proceedings, vol. x. p. 152, 
