316 VAN HISE—METAMORPHISM OF ROCKS AND ROCK FLOWAGE. | 
(8) Energy is required to overcome the viscosity of the solutions, or, 
stated in a different way, energy is required to overcome the friction of 
the free ions against the water during their movements. 
(4) As a result of solution and deposition in the lower physico-chem- 
ical zone, the minerals produced are, upon the average, more compact 
than before the process. In so far as a more compact condition results 
energy is liberated. In the rare cases in which the minerals are equally 
compact before and after the process, as in the recrystallization of lime- 
stone, the energy of solution and deposition balances. In any case re- 
lease from strain liberates energy. 
We may now compare the energy demanded for each of the different 
factors in the two processes of granulation and recrystallization. The 
three factors entering into granulation are paralleled by the first three 
of the factors entering into recrystallization. (1) It appears probable 
that the energy required to produce granulation is greater than that re- 
quired to produce a state of strain during recrystallization. (2) The © 
-energy required for the actual transfer of the material by granulation 
and by solution may be supposed to be the same. (3) The energy re- 
quired to overcome friction during granulation is certainly vastly greater 
than the energy required to overcome the friction of the ions against 
the water during the transfer of the material. (4) Asa result of the solu- 
tion and redeposition, the minerals, upon the average, are changed to a 
more compact form, and by this reaction energy is liberated rather than 
consumed. 
Therefore we may safely infer that the great excess of energy required 
in order to accomplish granulation, on account of the probably greater 
work of subdivision, the much greater work to overcome friction, and 
the energy usually released by the chemical reaction in recrystallization, 
render it reasonably certain that the energy required for granulation is 
certainly considerably greater, and may be several times greater than 
that required for recrystallization. 
If one premises that when the conditions are such that either granu- 
lation or recrystallization might occur the process takes place which 
requires the less expenditure of energy, this furnishes additional sup- 
port to the above conclusion, for wherever the conditions are such that 
recrystallization can replace granulation this occurs. 
In the artificial deformation of limestone in the experiment performed 
by Adams the deformation was accomplished by granulation. When the 
deformation is made in the presence of water, as Adams proposes, it is 
probable, as already suggested (page 310), that the adjustment will be 
largely by recrystallization. It would be very interesting and impor- 
tant, if it were practicable, to compare the amount of work done upon 
