46 THE DEVONIAN AND CARBONIFEROUS. |bull.80. 



and this with the "sandstone of Bochester" is regarded as New Bed 

 sandstone. The rocks of the fourth district are considered as belong- 

 ing to the " Old Bed sandstone and the Carboniferous group," and to 

 lie "above the Silurian system of Mr. Murchison," a conclusion based 

 in part upon the organic remains. 



This confusion was doubtless due to the fact that the Wernerian 

 method, which, somewhat modified, was seen in the earlier works of 

 Eaton, was inconsistent with the new method which was being elabo- 

 rated by the New York State geologists. Those who thought in terms 

 of the first considered the new method revolutionary. 



Prof. Eaton's systematic work heretofore followed the English treat- 

 ise on geology by Bakewell. In an article which appeared in 1840 1 he 

 quotes an outline of the system of Brongniart, proposed in 1829, which 

 he states the author still maintained in 1840. As Eaton used this sys- 

 tem and attempted to defend its application to Americau rocks, it may 

 be worth while to record Brongniart's system of classification : 



1. Primitive class (Agalysient, overthrowing or breaking up by internal 



forces). 



2. Transition class (Hemilysient, half breaking up by internal forces). 



3. Lower Secondary class (Abyssient, deepest abyss of the ocean). 



4. Upper Secondary class (Pelagient, the ocean). 



5. Tertiary class (Thalassieat, the sea). 



6. Diluvial class (Clysmient, the deluge). 



7. Alluvial class (washed). 



It will be seen from the terms used that Brongniart considered the 

 rocks to be formed in the Primitive class by the overthrowing or break- 

 ing up processes due to internal forces; the Transition class, half to 

 this operation ; the Lower Secondary class, to the sedimentation of the 

 deep abyss of the oceau ; the Upper Secondary, to the ordinary depo- 

 sition of the ocean ; the Tertiary, to the shallow seas or modern seas ; 

 the Diluvial, to floods or deluges on the land; and the seventh, 

 Alluvial, to the washing of rivers and streams. 



The general theory of this interpretation of the strata was proposed 

 earlier by Lehmann, and is associated with the general notion that the 

 earth was formed from water solution — first, by a chemical crystalliza- 

 tion and deposition, and later by sedimentation from the ocean, at first 

 higher up in the hills, and, as the water evaporated, lower down in the 

 valleys. This general theory pervades various systems of the early part 

 of the century, and may be regarded as the fundamental theory of 

 Werner, determining his method of classification and of correlation. 



In the present article, Eaton attempted to point out the limits be- 

 tween the various divisions of Brongniart in our own strata. He rec- 

 ognized the well known Stockbridge marble of Massachusetts as the 

 upper stratum of the Primitive class. Second, he regarded the " Cor- 



1 Amos Eaton: References to North American localities to be applied in illustration of the equiva- 

 lency of geological deposits on the eastern and western sides of the Atlantic. Am. Jour. Sci., voL 

 39, p. 149. 



