Origin of Stratification. 203 



main unaltered in any great degree by heat or dislocation, the 

 stratification produced by the several causes may be clearly 

 seen and studied. On the western edge of this deposit, we 

 have rocks composed of strata, which would at once be 

 referred to the action of tides or inundations by the most in- 

 experienced observer. The strata here vary from one tenth of 

 an inch to one inch in thickness ; they are also covered with 

 mud-cracks, and the various markings which are usually found 

 upon a shore or beach. In other portions of the valley, we 

 have strata divisions occasioned by the lines which separate 

 materials differing either in quality or nature, as in the shales 

 from the sandstone, the coarse conglomerates from the fine 

 sandstone, or the highly bituminous shales from those less 

 bituminous. And then upon the extreme eastern edge of this 

 sandstone deposit, w r e find strata, the leaves of which mea- 

 sure from one to two, and in some instances, three feet in 

 thickness, each embracing in itself matter ranging from a 

 coarse conglomerate to the finest sand ; and yet none of these, 

 within the limits of the particular strata in which they are 

 included, exhibit the slightest tendency to break or divide in 

 any one direction more than another. 



The observations here stated, I am happy to find, have been 

 also noticed to some extent by others conversant with the 

 subject of stratification. Sawdust, subjected to the filtering- 

 action of water, has been observed by Professor Agassiz to 

 assume a regular stratified appearance. The same has also 

 been noticed by Dr Hayes of Boston, in the vats into which 

 clay, used for the manufacture of alum, is washed- I have 

 also noticed regular stratification in the dried deposit of a 

 puddle in the streets, where no apparent change in the cha- 

 racter of the materials deposited could be noticed, and when 

 there was certainly no interruption of deposition. 



If the divisions of stratification which I have thus pointed 

 out be admitted, it is not improbable that many cases of what 

 are now considered disturbed and tilted strata are none other 

 than their normal condition. 



Dr Emmons remarked that he agreed entirely with the 

 views brought forward by Mr Wells, and referred to cases 

 of clay beds, in which certain strata were contorted and in- 



