THE FARMER'S REGISTER. 



429 



which he made by order ofihat state. All the 

 etone limes which have been longest and most 

 largely used ibr manuring in Pennsylvania, and 

 which have produced so much lertilizalion and 

 profit, have been highly magnesian. So our 

 James river farmers need not hesitate about pro- 

 fiting by their present cheap supply, nor fear dan- 

 ger li-om this large admixture of magnesia in the 

 Schuylkill stone lime, when appled in their usual 

 moderate (juantities of 36 or 40 bushels (slaked) 

 at one dressing. In New Jersey I heard ol' 75 

 and 100 bushels being used without suspicion of 

 their being danger from magnesia; and probably 

 most of those who applied it had no knowledge 

 of the presence of magnesia. 



1 have aimed throughout this inquiry to obtain 

 and present the opinions of others, rather than to 

 give my own views most prominency. And when 

 the most experienced and well-informed practical 

 improvers differ so much on this subject, it could 

 not be expected that my hasty digest of their opi- 

 nions should be entirely free from contradictions. 

 In truth, my own opinions have not remained the 

 same, at different scenes of this hasty examination, 

 nor even during the writing of both the earlier and 

 the latter part of this account. While I have 

 learned much as to the effects and value of this 

 manuring earth, by my inquiries and personal ex- 

 amination, I have at the same lime also learned 

 that 1 was before, and still am, profoundly ignorant 

 of the cause and manner of ihe action. I will not 

 even presume to attempt any explanation of what 

 appears to me so Jar inexplicable by any of the 

 views yet set forth. 



There seem to be important differences of action 

 between the green-sand of New Jersey and that 

 of James river. It is true that the latter has 

 been usually applied by myself in very small 

 doses, say 20 lo 40 bushels the acre, while in 

 New Jersey the quantity is usually 200 bushels 

 and often much more. But even this great differ- 

 ence of quantity does not at all serve to explain 

 the differences of results — nor do the manifest 

 differences of the different earths, or of the soils 

 of the different regions. So far as my practical 

 experience has extended, the green-sand earth 

 of James river acts precisely as does gypsum, 

 though more strongly — is limited to the same 

 soils, to the same crops, and like gypsum has but 

 a temporary though more extended limit of time 

 of action. But the green-sand earth of New 

 Jersey while agreeing greatly with that of James 

 river m its visible effiects (epecially on clover.) 

 seems to act on nearly all soils, on most crops, 

 and is counted as a very long enduring if not 

 indeed a permanent fertilizer. 



All the best green-sand earths which I saw, 

 contain no carbonate of lime, or at most and in 

 very few cases, so email a proportion as to be of 

 no appreciable effect. They contain (according to 

 Prof. H. D. Rogers' statements of their contents) 

 from 85 to 95 parts of green-sand in the 100 of 

 earth ; and the pure green-sand (or silicate of 

 iron and pot- ash) contains from 5 to 14 per cent., 

 or generally 9 or 10 per cent, of potash. Since the 

 discovery of this latter ingredient was made by 

 Henry Seybert, esq., of Philadelphia, it has been 

 generally supposed to be the main if not the sole 

 fertilizing ingredient. I deem that opinion ex- 

 tremely questionable ; and, as to the green-sand 

 earth of Jamee river, altogether untenable. But 



I will not here repeat the grounds of this opinion. 

 The gypsum, which is certainly present in raoBt 

 if not all the green-sand earth of New Jersey, 

 has not been considered by the highest authori- 

 ties as being an important ingredient. Indeed 

 it does not appear among the contents in the 

 many analyses stated in Prof. H. D. Rogers' Re- 

 port. Without claiming Ibr it any very important 

 agency, still it seems to me that the gypsum can- 

 not be of so little amount or effect, as has thua 

 been assumed. And sulphate of iron (copperas) 

 and sulphate of alumine (alum,) which are pre- 

 sent in some cases, need only to meet lime in the 

 soil, or to have lime previously mixed with the 

 green -sand earth, to form still more gypsum, by 

 the decomposition and destruction of either or both 

 these salts, which are poisonous to soil and lo 

 vegetation. 



The following statements of the composition 

 of some of the bodies of green-eand earth referred 

 to or described generally in this article, are copied 

 from Prof. Rogers' ' Final Report' of liis geologi- 

 cal survey of New Jersey. 



In Gloucester — Josiah Heritage's. 

 " Composition. In 100 parts. 



Green-sand, - - - 93.70 

 Clay, . - . . 6.30 



Quartzose sand, - - none. 

 ** The proportion of potash in this marl, [form- 

 ing a constituent part of the green-eand ingre- 

 dient,] is 10.4 per cent." 

 Thomas Bee's. — " Composition. In 100 parte. 

 Green-sand, - - - 92.48 

 Clay, .... 7.52 



Quartzose sand . . none. 

 " The amount of potash in this marl by absolute 

 analysis is 10.35 per cent." 



Salem county — John Dickenson (now Rich- 

 mond Dickenson's) 

 " Composition. In 100 parts. 



Green-sandj ... 92.59 

 Clay, .... 7,41 



Quartzose ... none. 

 " The proportion of potash in this marl, by 

 direct analysis, is 10.4 per cent." 

 Allen Wallace's — " Composition. In 100 parte. 

 Green-sand - - - 90.00 



Clay 8.00 



Quartzose . - - 2.00 



"The proportion of potash which this marl 

 contains by analysis is 10.2 per cent." 



Jonathan Cawley's — " Composiiion. In 100 

 parts. 



Green-sand, - - . 86 

 Clay, .... 14 



Quartzose sand, - - none. 



"The proportion of potash which analysis 

 shows in this marl is 10.3 per cent." 



Jonathan Riley's (part of the Woodstown dig- 

 gings.) " Composition in 100 parts : 



Green-sand, - - - 88.28 

 Clay, ... - 11.72 



Quartzose eand, - - none. 



Carbonate of lime, - - a trace. 



" The proportion of potash, as deduced from 

 the green-sand, is 10.1 per cent." 



James Smith's, Mannington Hill. •'' Composi- 

 tion, in 100 parts : 



Green-sand, - - - 88.80 

 Clay, . . - . - 10.20 

 Quartzose sand, - - 1.00 



