680 



FARMERS' REGISTER. 



Carter, heard of first only a few days ago, I have 

 known of but a single lact in regard to the eflecis 

 of green-sand alone, in Virginia, except in nny 

 own experimenis. And on these three experiment- 

 ers only will I etil! have to rely. Notwithstanding 

 ail the excitement produced in regard to green- 

 sand, by the opinions expressed in the state geo- 

 logical reports ol its great and general efficacy, and 

 aiihough these opinions have generally received 

 much respect and credence, which ihey owed en- 

 tirely to their authority, siill, so (ar as I have been 

 informed, there have yet been no other experi- 

 ments made with green-sand simply, in V^irginia, 

 on soil not calcareous, except in the cases just re- 

 ferred to. li is probable tfiat many other experi- 

 ments may have been made ; but", if so, I have 

 heard nothing of the results or the trials. 



But while confessing ignorance on this subject, 

 it is neither my wish nor my habit to wrap mjsell 

 up in prejudice, and repel light and instruction 

 from any quarter, even though it may serve to 

 show tiiat my opinions are erroneous. Besides 

 other less direct demands (or the practical inlbrma- 

 lion which I was so anxious to obtain on this 

 subject, more than three years ago, (at page 511 ol 

 Voi. V.,) 1 submitted particular queries in regard 

 to the effects of green-sand, addressed to all who 

 had used it. These produced not a single an- 

 swer, and probably induced not one experiment. 

 I still as earnestly desire information ; and will be 

 as ready to submit to such as will contradict my 

 views, as to welcome any in confirmation. But 

 until such disproof is furnished, [ may be excused 

 for trusting to my own practical experience, how- 

 ever contradictory it may be to closet speculations, 

 and the one-sided facts of geological reports. 



Therefore, until corrected by the more accurate 

 and full observations and experience of others, I 

 shall continue to hold these opinions in regard to 

 green-sand as manure in lower Virginia: 



That, whatever may be the source of power of 

 this earth, (which I deem as yet altogether unex- 

 plained,) it is similar in action and effects to the 

 equally mysterious manure, gypsum, or plaster of 

 Paris. 



That, like gypsum, if used in small or mode- 

 rate quantities, green-sand is only operative (or 

 at least profitable) on neutral and calcareous soils;, 

 and rarely even on these soils on any crop except 

 clover, and other plants of that family. 



That green-sand is not operative at al! on acid 

 or naturally poor soils, unless in unusual and ex- 

 cessive quantities ; and then, or in any mode o! 

 application, that the manure is, like gypsum, but 

 of temporary effect. 



And that, on acid soils, where it is least opera- 

 tive, after the land being marled (or otherwise 

 made calcareous) the green-sand, like gypsum, 

 generally becomes operative on clover. 



Although the facts are as yet much too {'eAv to 

 establish all these positions, I will venture to pre- 

 dict that accurate experimenters and observers 

 will, if trying proper experiments, find results in 

 accordance with my views. Thus I infer that the 

 pure green-sand earth (that is, containing no shells 

 or calcareous matter) will have no profitable if 

 indeed any effect, unless in enormous quantity, on 

 any crop on acid soils ; that it will generally have 

 good effect on clover on the same soils after marl- 

 ing, or when constituting part of the marl applied, 

 or on soils naturally calcareous or neutral ; and 



thai, even when most efficacious, if applied alone, 

 or in such munner that its single operation can be 

 estimated, the effect of green-sand will not be per- 

 manent, like calcareous manure, but temporary, 

 like gypsum. 



Now though I dissent altogether from the opi- 

 nion that green-sand is, like a quack nostrum, 

 a universal remedy lor all diseases of land, and 

 an improver of all soils and all crops, 1 value it 

 more highly than some who have most profited 

 by its use in conjunction with marl. Neitlier can 

 it be alleged upon any plausible ground that I 

 seek to disparage this manure, from prejudice or 

 envy. Every prompting of vanity, as well as of 

 self-interest, would induce precisely the contrary 

 course; lor [ own extensive and rich beds of this 

 earth, on the banks of James river; and, whatever 

 may be the measure of the value of this earth, the 

 discovery of its existence in V^irginia, the earliest 

 and most extensive trials of its effects, and the 

 first idea and assertion of its identity with the 

 (iimous green marl of New Jersey, all those me- 

 rits, if they be such, were mine — as will be suffi- 

 ciently evident to any inquirer who may refer to 

 sundry pieces in the early volumes of the 'Farmers' 

 Register,' on the New Jersey marl, and particular- 

 ly to the eailiest piece referring to if, my article 

 " On the gypseous earth of James river," publish- 

 ed in the first volume of the 'Farmers Register,' 

 (p. 207,) which was extended from a shorter and 

 much earlier communication to the old ' American 

 Farmer,' and both of them referring to the disco- 

 very of the bed of earth made as early as 1817. 

 It is very true, that being then, as now, ignorant 

 of geological science and systems, I had never even 

 heard of the term "green-sand," and of course 

 did not use it; and moreover the action of the 

 earth as manure \vas erroneously ascribed by me 

 entirely to the gypsum which it sometimes contains, 

 and not to the green sand, of which I knew nothing. 

 But the appearance and visible marks of the earth 

 were so niinutely and fully described, that it was 

 impossible for any reader of the account, acquaint- 

 ed with green-sand elsewhere, to have mistaken 

 the thing described, or to be doubtful of the simi- 

 larity, if^not idenlity, of the depositee. 



This earth is (bund in great abundance along 

 the banks of the Pamunkey, and, fortunately, ia 

 generally mixed with calcareous mail, to which 

 intermixture the undoubtedly valuable effect of 

 green-sand here is (as I infijr) almost entirely 

 owing. The beds of marl here are of the most 

 ancient class of the tertiary marl (^eocene') and in 

 them the calcareous ingredient has, to greater or 

 less extent, been removed, and substituted by 

 green-sand. Over these beds of marl, as on James 

 river, waters containing copperas (sulphate of 

 iron) and alum (sulphate of alumine) are still 

 oozing, and these salts are often perceptible both 

 to the sight and taste. When meeting with shells 

 or calcareous matter, both the former salts serve 

 to decompose the carbonate of lime, and (orm, by 

 new combination, sulphate of lime, or gypsum. 

 Hence the removal of the shells, while their hollow 

 forms yet remain perfect in the earth, and the total 

 disappearance in many cases, (and this is general- A 

 \y so in the beds on James river,) of every trace ^ 

 of calcareotis matter. And hence the appear- 

 ance instead, of the more newly formed gypsum, 

 in crystals, or in powder, as described in the ar- 

 ticle above referred to. But the gypsum has, in 



