T. &. Hunt on the Oriticisms of Prof. Dana. 43 
are in reality examples of isomorphism” [pages 364, 365 
Referring to the well-known investigations of Mitscherlich 
9 the crystallizing together, in all proportions, of isomor- 
phous species, and of the symmetrical crystallization of one salt 
around a nucleus of another isomorphous with it, Delesse sug- 
gests that the different forms and varieties of hornblendie and 
pyroxenic minerals afford many examples of the kind. He 
then adds, “ If, as Scheerer has remarked, water plays in silicates 
the part of a base, anhydrous silicates may erystallize at the 
‘somorphism, or homceomorphism, the association with pyroxene 
of the hydrous species, schiller-spar, as well as that “of vari- 
We may cite from Scheerer, as examples of what he call 
were isomorphism, the association (in the same crystals) of 
We have thus endeavored to set forth, chiefly in his own 
words, the views enunciated in 1859 by Delesse, according to 
Whom the phenomena of so-called pseudomorphism among 
— exposé notre maniére de voir), he says, ‘ We hasten to ad 
aia these facts may also be explained in a manner altogether 
ttferent (peuvent aussi s'interpreter d'une mantere toute différ- 
859). 
. That ‘the « pseudomorphism” of the authors just named 
ao. Dana or myseif who has misrepresented or misunderstoo 
less “ 
eee Ty : 
diffuse memoir of the latter, from which we have quoted, is 
