Editorial Comment. 113 
lustrations and a redundance of chemical interpretations which 
have made Dr. Hunt's writings unique in American geological 
literature. Among other facts he quotes the remarkable discovery 
of Murray and Renard, viz : that a decomposition of volcanic 
detrital material goes on at low temperatures in the depths of the 
ocean, transforming basic silicates, represented b}' volcanic glasses, 
such as hyalomelane and tachNiite, into a crystalline zeolite on the 
one hand, and the characteristic red clay of deep-sea deposits on 
the other. This goes on at a temperature approximating zero, 
centigrade. 
As a theory the "Crenitic h^-pothesis " is well set on its 
legs. It has to undergo j'et the fire of innumerable criticisms 
and the counteracting effect that may come from a more perfect 
knowledge of Archean stratigraph}- itself than is evinced hy the 
author. There is great diversity* in the Archean rocks, and 3'et a 
grand progression in their general lithologic aspects. A stumbling- 
block which the theory- will encounter at once is its "sweeping" 
scope. The Archean rocks are all subjected to its single operation. 
That has been the trouble with all former h3-pothesis. The}- have 
been based on partial evidence. All these rocks have been thrown to- 
gether in a lot, and if a part of them have been found explainable ' 
by any observed process, that has furnished foundation to explain 
them all. It will meet with another obstacle in the fundamental 
assumption that the supposed crenitic circulation of water in early 
Archean time would in the first instance, bring siliceous elements 
in solution to the surface, and would reject the basic elements. In 
the scale of solubilit}- silica ranks very low among the natural 
minerals, and it is questionable whether natural waters would pre- 
vailingly take it into solution to the neglect of the others. A\'ould 
not the order be the reverse from that supposed ? "Would not the 
natural effect be the rejection, as a whole, of the more insoluble 
siliceous elements, and the removal of the basic b}- solution ? Is 
it not after water has first become charged with alkalinic or other 
solvents that it attacks silica and carries it in solution ? Is it not 
true that the characteristic elements of the supposed residual 
stratum, (iron-oxide and magnesia) are themselves more soluble 
than the characteristic elements of the supposed crenitic stratum 
and hence that thej' would be brought sooner to the surface ? 
The hypothesis starts out with a statement of what appear to 
be contradictory postulates, viz: First, the primitive basic stratum 
is said to be ' 'the last congealed and superficial portion of a cooling 
