TACONIC SYSTEM. 23 



have been caused by exudations of different kinds from the primary rock, which filled up the 

 fissures near its surface, incorporating themselves with the sand, &c. deposited upon the 

 surface; the whole of which, by the agency of crystallization, undergoing a change of character, 

 giving rise also to a connection not easy to solve without much investigation. 



From the little to be seen of the Taconic system in the district, it might readily be con- 

 sidered superfluous ; but by directing attention to it in this prominent manner, a full investiga- 

 tion will follow. Moreover it is a convenient receptacle for deposits which belong neither to 

 the Primary or the New- York system ; and the mind in England is disposed to one of the kind, 

 since the Cambrian system holds the same position. From the necessity of a connecting link 

 between the Primary and the Secondary classes, which alone existed when Werner rose as a 

 geologist, we owe the Transition class, the fruits of which are, the Cambrian system of Mr. 

 Sedgewick, the Silurian of Mr. Murchison, and the Devonian of Mr. Phillips ; now 

 merged, with the exception probablyof a portion of the Cambrian, in the New-York system. 



