220 CALCAREOUS MANURES— APPENDIX. 



The whole, so far as dug, added to the before exposed bank, aniountec 

 to 66 feet of tlie eocene Jeposite, of which 49 feet was below the level ot 

 high tide. The last stratum, of which was penetrated 17 feet before the rise 

 of spring water compelled the work to be discontinued, was manifestly the 

 same with that at Evergreen which was even with high tide (and extend- 

 ing above and below,) and which was there 25 feet thick. It was a subject 

 of much regret, after so much labor, that the still lower stratum, full ot 

 shells, could not be reached, and which probably might have been done in 

 8 feet more of digging. However, enough was done to show that the quan- 

 tity is inexhaustible of the layers richest in green-sand, (whatever may be 

 that degree of richness, ) independent of the other layers. 



Besides the main object of this laborious examination by digging as low 

 as possible, to learn more of the quality and quantity of the earth for manure, 

 and as a matter of curiosity, there was another inducement. The whole 

 bottom of the river across to Berkley (below the thin covering of loose 

 and soft mud,) according to its variation of depth, must be formed of one 

 or another of the same layers shown in this digging of 49 feet below the 

 water level; and, of course, Harrison's Bar, which lies between the Coggins 

 and Berkley shores, must be so formed. No earth more strongly resists 

 the washing action of water than the gypseous earth, even when the least 

 mixed with clay. This peculiar quality must be the cause of the existence 

 of this bar, which presents so serious an obstacle to the navigation of the 

 river ; and it may be thence inferred what would be the degree of difficulty 

 of its removal, and also that the removal if effected would be permanent. 



Various and contradictory as had been many of the results of my ex- 

 periments of the green earth as manure, there had been perfect agreement 

 in some respects. Thus, as befoi-e stated generally, the earth has never 

 been beneficial as manure on acid soil— but rarely on corn, and never 

 (directly) on any other grain crops; and (on proper soils) generally and 

 greatly beneficial on clover, and perhaps all plants of the clover and pea 

 tribe— and the effects, when produced, have never been permanent, nor 

 even very durable. And the effects shown in these points of agreement 

 were nearly all the reverse of those ascribed to the New Jersey green- 

 sand. In regard to these effects, in the absence of all certain and particular 

 information to be obtained otherwise, I found it necessary to seek informa- 

 tion in person. The results of my inquiries and personal examinations, 

 in general, showed that the green-sand (called marl) of New Jersey, though 

 agreeing in some respects with ours in action as manure, is operative gene- 

 rally on the greater number of soils and on most crops, and is also very dura- 

 ble in effect. On the other hand, much larger quantities are applied there, 

 (usually 200 bushels, and sometimes 400 or more to the acre) than I have 

 done with ours ; and something of the more general benefit, and longer 

 duration may perhaps be owing to that circumstance.* Whether the green- 

 sand is indeed the principal, or a very important manuring agent, of the 

 James river earth, or whether the other ingredients may not be still 

 more active than its green-sand, is yet undecided. 



It is indeed strange that such doubts should exist at this late day as to 

 the manuring action and effect of this earth— and still more so that the 

 chemical composition and ingredients of the earth should not have been 

 long ago ascertained. Yet previous to the recent imperfect application of 

 tests above referred to, there had been no known full or correct chemical 

 analysis made of the earth in question ; nor even any partial examination 

 for and report of the ingredients, that was entitled to any respect for 



* See report at length on the New Jersey green-sand, and its operation, at jtage 418 

 vol. X. Farmers' Register. 



