34 ON THE STUDY OF 



highest mountains in alpine districts. In the 

 fissures between some of these rocks, veins of 

 metals are occasionally found. From this descrip- 

 tion of rocks, therefore, we obtain granite, marble, 

 porphyry, and many of the useful metals; and 

 from their solid, chrystalline character, and from 

 containing no animal remains or other deposits, 

 we are taught to consider them the first created 

 substances of nature. 



The second order of rocks has been deno- 

 minated transition or secondary, from its being 

 supposed to have been formed next in order 

 after the primary rocks. This, like the former, 

 consists of chemical productions ; but contains 

 also a portion of mechanical depositions, in which 

 the first appearance of fossil remains of animals 

 and vegetables is to be found. 



We learn from the organic remains and impres- 

 sions which these rocks contain, that zoophites 

 and shell fish, which are considered as forming 

 the lowest link in the scale of animal creation, 

 were the first that received the gift of life. 



The secondary rocks contain metallic veins in 

 a larger proportion than the primary ; and like 

 the rocks above them, water worn pieces of 

 other rocks. They consist of the minerals termed 

 grey wacke, transition or secondary lime stone, 

 transition trap, and transition flinty slate. 



Thus this description of rocks, while it supplies 

 us with materials for architecture, and a large 



