THE FARMERS' REGISTER 



123 



nnd proveii the popsiblily olexcellent clover beinc 

 madrt un ilie wliule piece, unit perliaps ilie whole 

 [both poor nnd iiiiirl-lniriii] ficlj. 



XXIV. " lS-28. Marcli. Twenty-two bushels 

 of <fyp.-eoiiis earth sown on a dark neiiliiil loam, 

 which had (oinierl)' been marled wiih uvpseons 

 marl. On clover, sown spring' ol" 1827. No 

 certain benefit." 



Ai another time, on this same field, and ofsimi- 

 lar soil, very creat effect was produced on clover, 

 by an application ol" pypseons earth. 



Various other applications of this jjreen-sand 

 earth were made, and some of lar^e e.xtent, 

 which were not recorded, and not accurately re- 

 membered, and which therelbre will not be more 

 particularly tjjeniioned. No journal or notes of 

 experiments were regularly kept later than 1828. 

 Uut 1 cannot (ail to remember correctly the causes 

 of my final loss ofconfidence in this manure. The 

 most remarkable clfccis stated of several of the 

 experiments, as well ad the slifrhler benefits else- 

 where obtained, (and all of which would seem, 

 at this time, if new, such convincinji proofs of the 

 great value of green-sand as manure,) all disap- 

 peared in a lew years, and rarely could be distin- 

 guished on the clover of the next succeeding rota- 

 lion. Considering, as F still did, that the effects 

 were produced by the <ry[)suiT> present, it seemed 

 that these transient and uncertain efiects would be 

 more cheaply obtained by sowinsr the gypsum of 

 commerce. This was then tried to the amount of 

 10 Ions or more. But though gypsum seemed to 

 act and to (ail as the green-sand earth would have 

 done, it is certain that the effects of the latter were 

 greater than gypsum sown in the usual quantity 

 ofa bushel to the acre, or even thrice that quantity. 



But though the green-sand and gypsum com- i 

 bined, and in large quantities compared to the! 

 gypsum of commerce, produced greater effect, i 

 yet, in every thin<r, except the degree of effect, "the 

 native and the purchased manure seemed to act 

 precisely alike. JNIy use of purchased gypsum 

 alone has not been considerable, and the results 

 have not been very carefully noted. But so far as 

 may be judged from such imperfect means o( com- i 

 |)arison, I in(er, (iom the foregoing experiments, , 

 and all the more extensive practice of which the j 

 results are not recorded, that the manner in which , 

 green-sand acts, whatever may be the cause, is j 

 similar to that of gypsum. And putting aside all 

 6uch judging by comparison with eypsum, I may i 

 venture to affirm positively the effects of green- | 

 eand manure, on such soils as mine, or m this tide- | 

 water region, to be as was stated al page 682 of | 

 vol. viii. viz.: j 



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

 rate quantities, green-sand is only operative (or I 

 at least profilablf) on neutral and calcareous soils; 

 and rarely, even on these soils, on any crop except | 

 clover, and other plants of that family. j 



" That green-sand is not operative at all on acid | 

 or naturally poor soils, unless in unusual and ex- | 

 cessive quantities; and then, or ia any mode of[ 

 application, that the manure is, like gypsum, but i 

 of" temporary effect. j 



"And thai, on acid soils, where it is least 

 operative, alter the land being luarled (or other- 

 wise made calcareous) the green-sand, like gyp- 

 sum, generally becomes operative on clover." 



And, in addition, that no matter how great the 

 effect produced by green-sand, it will not be per- 



mar.en', like marl, but temporary; and be at an end 



in the course of a ("ew years. 



These are the prools I have lo offer of my po- 

 sitions. I admit that iliey are too (ew, and have 

 been limited lo too narrow a locality, to settle the 

 question. Let others wi o have experimented 

 elsewhere in Virginia, present their results ; and 

 the comparison ol all will serve lo ascertain and 

 establish the true and important (acts, and with- 

 draw the subject of green-BOiur from the reoion 

 of baseless hypothesis, and (imcilul speculation 

 and unsupported assertion, to that of fact and 

 truth, established by experiment. 



It may be objected to all the foregoing experi- 

 ments, as well as to all my more extensive practice, 

 that in no known case was the green-sand used 

 alone, or without the accompaniment ol" gyp- 

 sum, the latter being the only substance then va- 

 lued and sought. 



'I'his would be a fiital objection, if my experi- 

 ments were brought (itrward to prove the effects 

 o(" green-sand to be either general, or considerable, 

 or durable, to even to the very limited extent 

 which I admit them to be. For part or even all 

 the effects which are shown above, might be at- 

 tributed to the gypsutn present, leaving none for 

 the green-sand. 



But it is no objection to the positions whicli I 

 maintain. For, however little of the eflects pro- 

 duced may be ascribed to the gypsum present, 

 the remainder, or even the whole effects, will not 

 show the green-sand lo be mo;e operative than 

 I allow. It happens however that I know of one 

 experiment made of green-sand without any ad- 

 mixture of gypsutn, and which will now be sta- 

 ted. It was made with great care, and with in- 

 formation ol" the constituent parts, and with a 

 view to the action of the green-sand alone ; and 

 several years alter! had abandoned the application 

 of this earth, as improfiiable. 



XXV. In 1835, when Professor Rogers was 

 on a visit at my house, made, at my request, 

 to examine these beds of green-sand, in addition 

 to showing liim all that I had belore seen, or was 

 visible at the surface, I had dug, for his better 

 examination, a pit on the beach of Cogirins 

 Point, of 7 or 8 feet deep, in what he supposed to 

 be one of the richest parts ol n)y bed of green-sand- 

 A specimen of this earth contained (as he repor- 

 ted) Irom 60 to 70 per cent, of pure green-sand. 

 In all the earth dug out, there was no gypsum 

 perceptible, or, suspected to exist ; and there were 

 a lew remaining, tnd scattered shells, but not 

 enough to furnish any appreciable value as ma- 

 nure. The earih, which this pit furnished, was 

 carried out, and spread, at the rate of 40 bushels lo 

 the acre, on young clover, on sandy soil (brmerly 

 acid and poor, but marled 8 or 10 years before, and 

 thereby much improved. The remainder of the 

 piece was sowed with purchased gypsum at the 

 rate of a bushel to the acre, except a broad strip 

 between the green-sand and the gypsum, left 

 without any. The gypsum produced a very de- 

 cided benefit, and the green-sand, at fir.-^t had still 

 more effect. I kept no note of this experiment, 

 and perhaps may not remember the degree of 

 eH'ect produced. I know however that it did not 

 at all compare with the best eflects which I had 

 before obtained from gypseous earth on naturally 

 good and calcareous soils; and further, alter one 

 course of crops, and the return of clover four years 



