THE FARMERS' REGISTER. 



235 



permanent manure, time must decide. Althouifh 

 I think your reasonio^ upon calcareous manures 

 conclusive, I ivould liiin hope they may not he 

 (bund so as respects green-sand. That is a sub- 

 ject as yet, I tliiniv, but lilile understood by farm- 

 ers, geologists, or chemists, as it would seem, at 

 least in our country. Its etTects we know but 

 little of; of its constituent character nothing. It is 

 true, Prolessor llogers tells us it is the "silicate of 

 iron, and potash"." We poor farmers are perhaps 

 now as wise as we were before ; but il' the pro- 

 fessor means to say, il is sand, iron, and ()olash 

 in a state of combination, I should think that 

 those materials would iorm an insoluble, semi- 

 transparent, vitreous compound, which the oxalic,- 

 humic, and all other acids, said to be contained 

 in the earth, would hardly decompose. Cut to 

 return. 1 cannot agree with you, that, the effect 

 ol green-sand is only that of gypsum. I think 

 so, first, because gypsum acts only on the clover, 

 and other broad-lealed plants, giving at first, to be 

 sure, an impetus to some of the grains, but no 

 increase to the crop that I could ever discover ; 

 whereas the green-sand not only produces a 

 greater effect upon clover, but all oilier grasses, 

 as I have seen a growth of hen's grass convert- 

 ed, by its appplication, into luxuriant white clover 

 and green-sward, as well as weeds of every de- 

 scription quadrupled in size ; and land that! am 

 satisfied would not have produced more than 2 

 barrels of corn to» the acre, by its application 

 alone, now produce 4 or 5. Now in this I cannot 

 agree, that it is the overdose of the gypseous mat- 

 ter that produces these effects; as I have never seen 

 any belter effects produced from any larger (]uan- 

 tity of plaster liran one bushel to the acre. Not 

 so the green-sand ; the larger the quantity I have 

 yet applied; or seen applied, the better the effects. 

 2d, I have never se^n gypsum have any effect 

 in neutralizing an acid soil, whereas after the ap- 

 plication of a sufficiency of green-eand the sorrel 

 ceases to grow. And 3dly, I have never seen any 

 change in the appearance of the soil itself, pro- 

 duced by any application o!' gypsum, whatever, 

 much or little, and I have been in the habit of 

 using it for the last 15 years pretty freely ; neither 

 have I seen any permanent improvement of the 

 land by its use, its beneficial eHects seeming, on 

 our soils, always lo have passed off with the ef- 

 fects of the clover, like any kind of putrescent ma- 

 nure on acid soils. Whereas, alter the application 

 of our green-sand, there is a manifest change 

 in the appearance of the soil, and a continued 

 fertility imparted thereto, as is evidenced by the 

 growth of every thing on it, whether it be of 

 grain, grass, or weeds.* How long this increased 

 fertility may continue is yet to be determined ; 

 but as " sufficienl for the day is the evil thereof," 



* We did not, in our recent articles, (p. 679, vol. 

 viii. p. 118, vol. ix.) ascribe the effects of green-sand 

 earth to the gypsum contained, (though that was 

 our error, twenty years- ago,) and still less did we 

 mean that green-sand and gypsum were the same. We 

 only maintained that the manner of action of the two 

 was sinfllar, though we readily admit the greater effect 

 of the green-sand. We have found the effect of gyp- 

 sum to increase with the quantity applied, from one 

 bushel to four to the acre; but not in equal proportion. 



I should recommend iis continuance until its use- 

 less, or jjernicions ellects are more manilijst than 

 I have yet seen them. Now, in the case of my 

 brother Carter's field at Newcastle, there was ns 

 much green-sand as green-sand marl applied, 

 the land seemingly of equal quality, and yet there 

 appeared to be no difference in the crop of corn ; 

 all seemed equally good, at least 100 percent, up- 

 on what the land would liave produced without it.f 

 What may be the chemical action produced 

 on soils, or vegetal ion, by the combination of lime 

 and green-sand, I am not agricultural chemist 

 enough to determine. But from your analysis of 

 my marl, or rather the marl I am using, I should 

 not suppose (here was lime or green-sand enough 

 to do much good ; but still the effect, as it appears 

 to me, has been very great on my land. J It may 

 perhaps be proper that I should here remark, 

 that the happiest effects I have witnessed from 

 the application of green-sand, was on a piece of 

 land that had been previously marled, with a poor 

 marl, which to the eye had not given much in- 

 dication of improvement. But as soon as the 

 green-sand (pure) was applied, a new appear- 

 ance was produced; the while clover, and patches 

 of green-sward began every where lo make their 

 appearance. This piece of land was very light 

 and sandy, with a gravelly subsoil, and not ca- 

 pable, beibre it was improved, I should suppose, 

 of producing more than 2 to 2^ barrels of corn to 

 the acre. Last year il was in corn, and produced 

 at least 8 or 9 barrels, (my overseer says 10) the 

 adjoining land, in anolher field of originally simi- 

 lar soil, did not produce 1| barrels to the acre. 

 In the absence of all chemical knowledge on the 

 subject of green-sand, (as Tconsider we know no- 

 thing of it analytically, and as the eye, and its ef- 

 fects, are all we have to direct us in its use,) I 

 must think the deposite from which Mr. Williams 

 Carter made his experiment is not of the same 

 character as what we call green-sand lower down 

 the river ; as in his, if I recollect aright, there 

 are no shells at all, whether of a large or small 

 kind, whereas, in the deposites found lower down 

 the river, and above too, for aught I know, there 

 are always more or less of small shells, and inter- 

 spersed occasionally are found larger ones, of a 

 peculiar character, as well as the saddle oyster 

 shell; neither of which shells have I ever seen 

 or heard of', except in connexion with green-sand. 

 And neither have I ever seen the green-sand 

 where these peculiar shells did not more or less 

 obtain. And if your gypseous earth is like the 

 banks I have noticed at City Point, (with entire 

 defJirence to your better knowledge, and more ac- 



t The great improvement on Mr. Carter Braxton's 

 land, from the use of green-sand earth containing only 

 2 or 21 per cent, of carbonate of lime, and the appa- 

 rently equal and similar effect with the upper stratum 

 containing .36 per cent, of carbonate of lime, we con- 

 fess to be to us astonishing and inexplicable. But still 

 the facts do not yet contradict our viev.'s ; though they 

 will do so, should the effects of the lower stratum be 

 found to be permanent. 



t This was written while supposing the marl to be 

 as poor as 11 per cent. The force of the objection i« 

 removed by the subsequent analysis, showing 45.50 to 

 be the degree of strength, in carbonate of lime. 



