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Mr. Wells read a paper on the origin of Stratification, 

 in which it was shown, that earthy matter soaked and 

 washed with water for a considerable time, and then fil- 

 tered, separated itself into strata on settling, according to 

 the fineness of the materials. 



The general idea respecting the origin, or cause of stratifica- 

 tion, as expressed in geological text-books, or as inferred from 

 the writings of geologists, seems to be this, — that strata, or the 

 so-called divisions of sedimentary matter, have been produced 

 either by an interruption of deposition, or by a change in the 

 quality of the material deposited. This idea is well illustrated 

 by the desposition of matter by tides, or inundations, its subse- 

 quent consolidation, and a renewed deposition on the plane of 

 the former deposit. That such is really the cause of stratifica- 

 tion, in many cases, I do not dispute, but that there are other 

 causes which tend to produce, and have produced stratification 

 equally extensive and varied, is, I think, clearly shown by the 

 following observations. 



My attention was first drawn to the subject during the past 

 summer, while engaged in the analysis of soils. By the process 

 adopted, the soil was worked upon a filter for a considerable 

 number of days, in some cases for a period as long as two weeks, 

 and dried at a temperature of 250° F. The residue of the 

 soil left upon the filter, consisting chiefly of silica and alumina, 

 was found after drying, in every instance, to be more or less 

 stratified, and this too by divisional planes in some cases not at 

 all coincident with any division of the materials, although this 

 is apt to take place. The strata so produced were in some in- 

 stances exceedingly perfect and beautiful, not altogether hori- 

 zontal, but slightly curved, and in some degree conforming to 

 the shape of the funnel. The production of laminse was also 

 noticed, especially by the clearage of the strata produced into 

 delicate thin, parallel plates, when moistened with water. These 

 arrangements, it is evident, were not caused by any interruption 

 and renewal of the matter deposited, or by any change in the 

 quality of the particles deposited, but from two other causes 

 entirely distinct, and which I conceive to be these : first, from a 

 tendency in earthy matter, subjected to the filtering, soaking. 



