Crosby.] 164 [March 5, 
This last statement of Prof. Wyville Thomson is based upon a 
belief in the view concerning the permanence of continents and 
ocean basins, first distinctly stated by Prof. James D. Dana, which 
asserts that the existing general inequalities of the earth’s surface 
were outlined at a very early period in geological history, and have 
become sharper and more prominent with the lapse of time; or, in 
other words, that the greater conductivity and consequently more 
rapid cooling along certain radii of the primitive globe determined 
the position of the land masses, and that all subsequent geological 
changes, and especially the continued action of this primal cause, 
have only tended to emphasize the original contrast between con- 
tinent and sea, broadening and elevating the former, and narrowing 
and deepening the latter. And hence in continuing, Prof. Thomson 
says; ‘If this view be correct,’ as he evidently believes, “it is 
quite possible that until comparatively recent times no part of the 
ocean was sufficiently deep for the formation of a characteristic 
abyssal deposit.”’ 
Without desiring to call in question here the validity of Prof. 
Dana’s theory, I would observe in opposition to Prof. Wyville Thom- 
son’s conclusions based thereon — first, that since according to our 
present knowledge, carbonic acid is, after the diffusion of the volcanic 
débris, the one important and efficient agent concerned in the forma- 
tion of the red clay, it is easy to conceive that, before the enormous 
amounts of this gas now represented by carbonaceous materials in the 
forms of coals, pyroschists, and bitumens, and the still greater vol- 
umes locked up in the limestones, dolomites and iron ores of the 
globe, were removed from the atmosphere and, of course, in the same 
proportion from the ocean, the modern deep sea conditions might 
have obtained in shallower water; and, secondly, that the abyssal de- 
posits do not appear to be wholly unrepresented among the geological 
formations now exposed to our observation. As already stated, Dr. 
Carpenter has called attention to the evident analogy in modes of oc- 
currence and composition between the red clay and greensand which 
is so abundant at several geological horizons. Potash is an essential 
constituent of glauconite, and I am not aware that analysis has 
shown that this alkali forms more than one or two per cent. of the 
clay. We find a possible source of it, however, in decaying alex; 
marine no less than terrestial vegetation, including sensible amounts 
of potash as an essential ingredient: and Dr. Hunt has shown us how 
by the contact of these with aluminous deposits the alkaline silicates 
