482 INUTILITY OE GREEN-SAND AS MANURE. 



prefer a green-sand marl, however poor in carbonate of lime, to 

 any miocene (or other) marl thrice as rich in the latter and all-im- 

 portant ingredient, but destitute of the misunderstood and there- 

 fore highly prized green-sand. This erroneous view is the result 

 (and the only abiding result to agriculture known to me) of the 

 statements and instructions of the late geological surveyor, and his 

 exaggerated and unmodified panegyrics on the asserted value of 

 green-sand as manure the " discovery" of which in Virginia was 

 claimed as his own, and cried up as the greatest possible benefit to 

 agricultural improvement. Yet still (and long before that gentle- 

 man had either written about green-sand, or seen so much as a hand- 

 specimen), my own use of this earth alone, far exceeded in quan- 

 tity all other applications in Virginia, and has only since been ex- 

 ceeded in amount by the later applications of my son and successor 

 on Coggins Point farm ; and no user of it has yet been rewarded 

 for his labour, from any possible effects of the green-sand alone. 

 All the appreciable and known benefits have been produced by the 

 gypsum, or the carbonate of lime, or both, used generally in con- 

 junction. Where neither of these aids was present, either in 

 the manure or the soil, I have never yet heard of a profitable use, 

 in Virginia, of the earth having no manuring ingredient save the 

 green-sand. Still, I do not deny that it may be valuable and 

 should be much gratified and greatly profited as a farmer, to be 

 assured that such value and profit as have been claimed for this 

 earth are indeed available. In my own extensive trials of the 

 green earth of James river, and the still more extended and more 

 beneficial recent applications on my former property, by the present 

 proprietor, there has been no effect found that could be ascribed to 

 green-sand, or to its potash or to anything but the gypsum, and 

 that only on either marled or naturally calcareous or neutral soil. 

 And in the much more extended practice of my neighbours on the 

 Pamunkey, who have largely used this earth as marl, but almost 

 always more or less intermixed with some carbonate of lime, there 

 is nothing in the known effects which would go to contradict the 

 opinions on this subject which I have here concisely, and formerly 

 at greater length, expressed. It is important to know all the value 

 of this earth as manure, and to avail ourselves of it fully; but to 

 do that, it is essential that the true source of the beneficial opera- 

 tion should be known, and that the delusion produced by the 

 influence of scientific but undeserved authority, should end, as it 

 surely will, soon or late. 



The occurrence of the very different appearances and qualities 

 of this formation, as found by digging, or in the natural exposures 

 on the river banks, has been generally deemed altogether irregular 

 and subject to no rule of position. Hence it was supposed that the 



