T. 8. Hunt on Lithology. 249 
may be considered as to a certain extent introductory to the pres- 
ent one, which will contain, in the first part, some theoretical 
considerations which it is conceived should serve as a basis to 
lithological studies. In the second part will be given a few de- 
finitions which may serve to render more intelligible the classifi- 
eation and nomenclature of crystalline rocks; while a third part 
will contain the results of the chemical and mineralogical exam- 
ination of some of the eruptive rocks of Canada. These results 
will be found for the most part in the recently published volume 
entitled the Geology of Canada. 
Thave already, in other places, expressed the opinion that the 
various eruptive rocks have had no other origin than the soften- 
ing and displacement of sedimentary deposits; and have thus 
their sources within the lower portions of the earth’s stratified 
views of many modern mathematicians and poyseets the school 
of geologists just referred to regard as a shell of very limited 
thickness, 
The view which I adopt is one the merit of which belongs, I 
believe, to Christian Keferstein, who, in his Naturgeschichte des 
Erdhirpers, published in 1834, maintained that all the unstrati- 
fied rocks, from granite to lava, are products of the transforma- 
€ Origin of metamorphism and of volcanic aie by the 
action of the internal heat of the earth upon deeply buried sedi- 
ments impregnated with water. (Proc. Geol. Soc. of London, 
Vol. ii, pp. 548, 596.) See also my papers in the Canadian Jour- 
nal, 1858, p. 206: Quart. Jour. Geol. Soc. 1859, p. 488; Can, 
Naturatise, Bes. 1859, and this Journal, [2], vol. xxx, p. 185. 
