100 HISTORY OF THE EARTH. 
to which we give the name of clay, of pure unmixed sand, of 
gravel and shingle — all these changes would proceed with much 
greater rapidity than at the present day. There would be pro- 
duced therefore, vast accumulations of the materials of the frag- 
mented rocks, containing no organic remains, which by the in- 
filtration of water containing silica dissolved in it, would be con- 
verted into solid masses of breccia, conglomerate, and clay-slate. 
The water of most springs is slightly impregnated with silica, 
but the hot springs of Iceland and the Azores, prove that the so- 
lubility of this earth is very greatly increased when the tempera- 
ture of the water is raised to the boiling point or above it. It is to 
this remote era therefore, that we must refer the large body of 
rocks ; flinty and clay-slates, hornstone, conglomerate, &c. that 
stretches across the midland counties of North Carolina; a branch 
of which follows the course and forms the bed of Morgan's creek 
between Barbee's and Meritt's mills, and communicates with the 
main body at a point four or five miles northwest of the latter. 
It is supposed to contain no organic remains, and to have been 
formed anterior to the existence of organized beings, whether 
animal or vegetable. 
South-east of this and altogether different from it, in constitu- 
tion, structure, color, and the kind of soil produced by its de- 
composition is a body of sandstone, extending nearly across the 
state, which contains coal in Chatham, and as this substance is 
supposed to have had a vegetable origin, it is inferred that during 
the period when this sandstone was in the act of being formed, 
there must have been dry land at no great distance from the beds 
of coal, and that the existence of vegetable organized beings upon 
the earth had commenced. This sandstone is not known to 
contain any remains of animals, and furnishes therefore no evi- 
dence of their existence at the time of its formation. 
54. With the exception of a few beds and masses of shell lime- 
stone, in the low conntry, of limited extent, and mostly covered 
by the sand, all the formations in North Carolina of later date 
than the sandstone are of very recent origin. In tracing the 
succession of events and of animal and vegetable forms, we are 
compelled therefore, to direct our attention to some other por- 
tion of the earth's surface for proofs and illustrations that are not 
found in the region in which we live. In an investigation of 
this kind, it is of but little importance from what quarter of the 
world these are drawn. For reasons already given ; because in 
the English strata there is a long succession of secondary forma- 
tions, within an area of moderate extent; (Sec. 29.) and these 
have been studied and described with as much accuracy as those 
of any country ; it is to the south-eastern part of the island of 
Great Britain that our attention will be first and princially di- 
rected. 
It appears that nearly all of the transition and secondary strata of 
England contain organic remains imbeded in them, and that these 
