J. D. Dana on the Consolidation of Coral Formations. 361 
is no drying in the process, it was suggested with hesitation that 
there might be a chemical action under the influence of the mag- 
nesian salts of the ocean, leading to a double carbonate of lime 
and magnesia, that is, a dolomisation,—Haidinger and von Mor- 
lot having shown that such a chemical change may be produced, 
at least under the influence of heat, and B, Silliman, Jr., having 
found a specimen of reef-rock to be a magnesian carbonate of 
mote, through the play of molecular forces thus set in action, (a 
kind of catalytic or “ presence” influence, ) the solidification of the 
mass by the crystallization of the carbonate of lime in solution,— 
a play of forces of one kind inducing the molecular action result- 
ing in cohesion; and the same circumstances or condition would 
be particularly favorable for chemical changes, like that of dolo- 
misation: 
Prof. Horsford deserting in part, his favorite theory, here takes 
the old ground that consolidation may result through the car- 
of the animal matter within the coral mud,—which appears to 
be a sensible idea. 
do not understand this “mobility.” Infusorial mobility is out of 
the question ; and what else shall we suppose was intended? The 
developed carbonic acid might shove the particles first one way, 
and then another, but this is not a consolidating process. 
mobility, and thereby promote conso 
though strangely expressed. he means (seemingly he does 
not) that the process of decomposition is one romotive of con- 
solidation, by a sort of catalytic influence, 
ight have been more distinctly explained. 
# Dana's Exp. Exp. Geol. Report, p. 153 
Srconp Sznms, Vol. XVI, No. 48—Nov., 1853. 
