8 GRANITIC ROCKS OF CORNWALL. [Ch. II. crystalline and non-fossiliferous masses, both compact and schistose, which are usually associated together under different arrangements, and intimately connected by frequent mineral transitions. This proposition may appear to some to be inadmissible, on the ground that the rocks thus brought together belong to several distinct geological epochs: but, admitting this view of the subject, (for, though it will be disputed hereafter, it is immaterial at present,) still these rocks constitute such a natural family, that they may be examined and described as such, independently of all theoretical considerations concerning the nature of their origin. Since this is a point that ought to be satisfactorily established, it may be stated, for the sake of the general reader, that Lyell admits that, “ if we investi gate a large portion of a continent which contains within it a lofty mountain range, we rarely fail to discover another class, very distinct from either the subaqueous deposits or volcanic rocks; and which we can neither assimilate to de posits such as are now accumulated in lakes or seas, nor to those generated by ordinary volcanic action.” Again, he adds, that “ nothing strictly analogous to these ancient form ations can now be seen in the progress of formation on the habitable surface of the earth; nothing, at least, within the range of human observation.” * Since these remarkable form- ations are so distinct from all other kinds of rocks, no great disadvantage can arise from our treating of them under the denomination of primary rocks ; it being always remembered that this name is not used in a theoretical signification. Having offered this apology for the employment of a term so objectionable, we will now proceed to our task without farther preamble. The primary rocks generally impart to a country a wild and desolate aspect: here and there, indeed, landscapes of great luxuriance and beauty present themselves; but the Principles of Geology, vol. iii. p. 10, 11.