PSEUDOMORPHOUS MINERALS OF NEW YORK. 241 



the " dirt bed," and the sand uniformly found beneath it, that the 

 trees have been thrown down in the place where they gi-ew. 



The surface soil, for perhaps forty miles in all directions from 

 this locality, is a deep, fertile loam, bearing no cedars or pines, 

 while this ancient surface had a substratum of sand, in which 

 the ConifersB delight to grow. This, with all the other circum- 

 stances, goes to sustain the conclusion, that the formation called 

 the diluvium of Ohio, is of comparatively ancient origin, and has, 

 therefore, been con-ectly named in contradistinction to alluvium, 

 which implies the agency of the present streams. Some circum- 

 stances indicate that the remains of the mastodon are cotempora- 

 neous with this formation. Mr. Lyell is now attempting to solve 

 the problem of the geological age of these fossils. The above 

 circumstances may possibly aid in the interesting research. 



On some Pseudomorphous Minerals of the State of New 

 York. By Lewis C. Beck, M. D., Professor of Chemistry 

 and Natural History in Rutgers College^ Neiv Jersey. 



The terms pseudomorphous and metamorphous have been ap- 

 plied to those minerals which possess a crystalline form that 

 is foreign to them ; and which they have received from some 

 cause entirely distinct from their own powers of crystallization. 

 Haidinger, however, has more appropriately, and perhaps more 

 definitely, applied to such formations the term parasitic, which 

 denotes the intrusive nature of the new compounds in prejudice 

 of those which existed before. 



The most extended notice of this curious subject which I 

 have met with, is that published by Haidinger, in the ninth and 

 tenth volumes of Brewster's Eclinbm-gh Journal of Science, (1828 

 and 1829.) Since that time I am not aware that much has been 

 done in the way of collecting facts, nor that any attempt has 



