4 QUARTERLY JOURNAI. . 



doned by many of the European writers. In consequence of thii 

 others have been proposed as substitutes, and have been adoptflM 

 in part; but the j^roposed names are about as objectionable as th 

 old ones, and hence much hesitancy has been manifested in the: 

 adoption. Without attempting to decide which nomenclature : 

 best, I shall use that which the public is most fc miliar with. 



The word primary is a term whose meaning is well fixed in thi 

 country, being applied to those masses which were consolidated m 

 fore the creation of organic bodies. This term, then, will be used t 

 designate a class whose existence was anterior to that of organ: 

 beings. It is true that some masses belonging to this class ha' 

 been in a liquid or fused state since the existence of organi 

 bodies ; still, so far as observation extends, the great mass or cr 

 of the earth is made up of granite, gneiss, mica slate, hornble 

 serpentine and primary limestone; and doubtless these mai 

 were consolidated anterior to the period spoken of. 



The word sedimentary is another term, the meaning of whi 

 cannot be misunderstood or misapplied. It will be used to de 

 nate those masses which are really consolidated sediments, 

 will often be used as synonymous with the word stratified^ ina 

 much as all sediments are disposed to arrange themselves in laye 

 or strata. The materials in this case lie in parallel beds, varyh 

 greatly in thickness ; all, however, separable from each oth 

 through the planes of deposition, each of which may be disti 

 guished by lines upon the faces of a ledge, by some diversity 

 the materials, or difference in the colors of two adjacent bee 

 Other lines, however, appear both upon the ends or surfaces 

 beds, which are not indicative of bedding planes. Thus, wh< 

 we find regular forms as rhomboids marked upon rocks, they a 

 not to be taken at all as the result of deposition. No differe 

 of materials or difference of color can be discerned along t 

 lines. Such regular forms are therefore the effects of crystaliz 

 tion. In some masses, however, both kinds of planes may 

 found. If the beds are horizontal, the upper and lower plan 

 are those of deposition ; but they may lie in any other directio 

 as the vertical, or oblique in various degrees. The other lin 

 course along upon the planes of deposition, and produce rhoi 

 boids or other mathematical forms. In other cases, again, a/f-t) 



