T. S&. Hunt on Alpine Geology. P 11 
a certain re-arrangement, so that the beds of these “ pretendus 
schists crystallins’ of the carboniferous are with difficulty dis- 
tinguished from the “ vrais schists erystallins ” upon which they 
rest unconformably. I insist the more upon these details, be- 
cause in the earlier notice of Favre's investigations I erroneously 
represented him as including in the carboniferous a great mass 
of the older crystalline schists. 
In this connection we may cite the observation of Sedgwick, 
who cites similar cases of recomposed rocks in Seotland, “which 
it is not always possible to distinguish from the parent rock,” 
and remarks that “‘a mechanical rock may appear highly crys- 
talline because it is composed of crystalline parts derived 
from some pre-existing crystalline rock.”* Emmons also has 
called attention to the existence of secondary or recomposed 
beds of talcose, chloritic and micaceous schists in the Taconic 
hills of western New England, which, according to him, have 
been confounded with the older parent rocks. It would hardly 
ag 
gates also noticed Oy Saussure as closely resembling the older 
* Geol. Transactions (1835), iii, 479. + Ibid., iii, 334; Geol. Journ, v, 210. 
