Siruduj^e of the Earth. 377 



or argillaceous strata, being water-tight, give rise to springs, as 

 arrest the water that runs through the porous strata, and convey 

 it to other situations. The inclinations of the strata, with the 

 breaks and inequalities, render the globe habitable, by distributing 

 the waters over the surface. 



According to geologists, all the substances which now constitute 

 rocks, mountains, and soil, on the surface of the earth, were orig-^ 

 inally existing in a state of solution in the waters of the ' great 

 chaos.' It is supposed, that they, at the bet.'.inning surrounded 

 the globe at a great depth. The substances or materials of rocks 

 thus swimming in the primitive ocean were supposed to fall grad- 

 ually to the bottom^ sometimes by chemical, sometimes by me- 

 chanical means, and sometimes by both togethei-; and in this man- 

 ner all the rocks were formed which we now find on digging into 

 the earth. The inequalities of mountains and valleys on the sur- 

 face of the ea;th, which were thus produced as soon as the wa- 

 ters began to subside, gradually rose out of the priiniiive sea, and 

 formed the first dry land. The rocks which were first form- 

 ed in this manner are called Original or Primary Formation; 

 because no fossil remains of animals or vegetables, nor any 

 fragments of other rocks were found imbedded in them; henca 

 it was supposed that they were formed before the creation of or- 

 ganized beings. The rocks of this class, are for the most part 

 extremely hard, and the minerals of which they ar-e composed are 

 frequently more or less perfectly crystallized. 



The formation of these rocks, however, did not, it seems ex- 

 haust the materials floating in the waters, for the deposition went 

 on, and a class of rocks were formed called Inie/rmtdiaie. or Tran- 

 sition Rocks; because, on their appearance above the water, the 

 earth was supposed to pass from an uninhabitable to a habiiQble 

 state, for nearly all the rocks contain organic remains of the 

 lowest class of animals, which are considered as forming the fii-st 

 link of the chain of animated beings. They contain also frag- 

 ments of rocks of the primary class, and are frequently interposed 

 betVv'een those of the primitive and secondary formations, and often 

 partake of the characters belonging to both. The rocks of the pri- 

 mary and transition classes are the principal repositories of me- 

 tallic ores. Roclcs of the transition class, however, are not uni- 

 versally interposed between the primitive and secondary ones, 

 for in some instances the transition series are entirely wanting. 



After the formation of the primary and transition rocks, it is 

 supposed that the water suddenly rose over them to a great height 

 covering them in many places, and it again -^suljsided with a new 

 formation called Lower Secondary Rocks. They are nearlv all 



