456 GYPSEOUS EARTH OF JAMES RIVER. 







What first directed my attention to this earth was the existence 

 in the river bank at Evergreen (the place of my birth, and of resi- 

 dence in early life,) of curiously shaped and beautiful crystals, 

 which subsequently I learned were selenite or gypsum. The like 

 crystals (though much smaller in size) I soon after found in differ- 

 ent places at Coggins Point, my own farm and then residence. And, 

 in making examinations for this purpose, I observed that wherever 

 any gypsum could be found, it was always in a peculiar kind of 

 earth, which, though varying much in appearance in different places, 

 and at different elevations at the same place, yet possessed charac- 

 teristic marks by which it could be easily distinguished from all 

 others. This was the earth in question. For want of any known 

 or more appropriate name, I at first applied the term " gypseous 

 earth" to this deposit ; and though I subsequently abandoned this 

 name in (undeserved) deference to scientific authority, and have 

 used instead, in my later publications, the name "green-sand earth," 

 I now believe that my original term (in reference to the more gene- 

 ral and universal manuring qualities) was the better of the two, for 

 reasons which will appear in the course of these remarks. And 

 besides that " green-sand earth" is inconvenient for its length, it is 

 not truly descriptive ; for the entire granules from which the pe- 

 culiar character of the earth is derived, are not green, but black 

 superficially, or so appear ; and are not what is usually understood 

 as sand } but in texture are like fine and unctuous clay. Still worse 

 is it to term the whole mass " green-sand," as is usually done when 

 the pure "green-sand," even if that were properly named, may not 

 form one-fourth or even one-tenth of the whole mass of earth. I 

 therefore would prefer for the deposit, and shall use indifferently, 

 either my first designation of gypseous earth, or the name of green 

 earth, which latter is convenient, is sufficiently descriptive, and, 

 moreover, affirms nothing except as to the colour, which is generally 

 manifest in the whole mass, and, if not, is certainly so in the sepa- 

 rated and mashed granules, which distinguish the earth. 



As the lower part of the river bank is mostly exposed and kept 

 bare by the frequent washing by the waves driven by strong winds 

 and high tides, the bed of gypseous earth can be easily traced 

 through nearly its whole course along the river side. As thus ex- 

 posed to view, it has generally a green colour, most frequently in- 

 termixed and mottled with smaller streaks and spots of bright yel- 

 low. The earth, as seen firm in the bank, and with a smooth wask- 

 ed surface, might be supposed to be somewhat of a clay; but, on 

 handling it, and breaking down a lump, its texture is more like 

 sand ; as indeed the larger proportion of the mass is silicious sand. 

 A very general distinguishing mark of this earth is its containing 

 numerous hollow impressions of eocene shells, of which the forms 





