CALCAREOUS MANURES— APPENDIX. 



231 



of merely calcareous marl would have been certainly either wasteful of the 

 manure, or injurious to the land. 



Many specimens of these Pamunkey marls and of the lower-lying green- 

 sand earth were subjected to a partial red heat, for the purpose of showing 

 whether suffocating sulphureous fumes were disengaged, as was stated 

 above (page 215 ) to be the case with some of the James river green-sand 

 earth. The lower stratum (very slightly calcareous) of the Pamunkey 

 marls, from Newcastle ferry, and at J. W. Tomlin's bank, gave out such 

 fumes, but not so powerfully as the dark gypseous earth of Coggins Point. 

 The next higher calcareous and green-sand stratum of J. W. Tomlin's, and 

 the same kind at Piping Tree ferry, and the blackish marl at South Wales, 

 all yielded these strong fumes, but in a still less degree. Sundry other 

 specimens of calcareous green-sand marl which were thus treated, yielded 

 no fumes. The latter results were found in specimens from the several 

 diggings at Newcastle, (both sides of the river,) and at G. W. Bassett's 

 bank. It may not be useless to repeat here, and thus to place in connexion 

 with these results, that all the dark green or blackish earth {D) of Coggins 

 Point gave out these suffocating fumes, and also the gray clay {E) below, 

 and most powerfully — and that no such product was found from any of the 

 very shelly bands. Thus it would seem that most generally the non-calcareous 

 earths (or nearly non-calcareous) gave out fumes, and the calcareous not. 

 But exceptions were found to both. And of the New Jersey green-sands, 

 containing no carbonate of lime, six specimens were tried at red heat, of 

 earths most esteemed for manure, and not the slightest disengagement of 

 such fumes was produced.* 



Of green-sand as an ingredient of miocene marls. 



In a previous page, (199,) the presence of green-sand in miocene marls, 

 as an important and general ingredient, was denied ; and the subject then 

 passed by, with the promise of its being subsequently resumed. Having 

 treated of the gypseous earth and of eocene green-sand marls, of both of 

 which green-sand forms large and important proportions, it is now most 

 appropriate to inquire into the alleged extent and operation of this sub- 

 stance in miocene marls. 



In 1834, Professor William B. Rogers (then a resident of lower Virgi- 

 nia) announced that he had discovered green-sand to be a considerable 

 ingredient of nearly all the many ordinary miocene marls which he had 

 examined either in place or by specimens; and from which observations he 

 inferred the same admixture to l3e general as to other miocene marls ; and 

 that the proportions of green-sand so contained were large enough to form 

 useful additions to, and in some cases the most valuable portion of the ma- 

 nuring ingredients of such marls, (Farmer's Register, vol. ii., p. 129.) At 

 a later time, he added to like general opinions and statements the following : 

 " In some of these deposites [marl beds in the vicinity of Williamsburg,] so 

 large a proportion as thirty and in some specimens forty per cent, [of pure 

 green-sand] has been found ; and in cases like this, if we are to trust to 

 the experience of New Jersey, a very marked addition to the fertilizing 

 power of marl must be ascribed to the presence of this ingredient." (Farm- 

 er's Register, vol. ii., p. 747.) In a subsequent communication to the Phi- 



* The New Jersey " marls" thus tried were selected by th« writer from the pits of 

 Josiah Heritage and Thomas Bee of Gloucester, and Henry Allen, Allen Wallace, J. 

 Riley, and J. Cauley, Salem county. The same results were found as to the poorer (or less 

 valued) overlying strata of Heritage, R. Dickenson, J. Cauley, and also of the barren 

 green clay or subsoil. See all described in my report on the New Jersey green -sand earths. 

 Fanners' Register, vol. x. p. 429. 



