48 



the benefits which they have produeed would most naturally and 

 reasonably be ascribed to those ingredients, already known for their 

 agency in ameliorating the land. On the Pamunkey the Eocene 

 marl has long been in use, but chiefly those beds have been selected 

 for the purpose of marling in which the largest proportion of calca- 

 reous matter was seen to exist. The lower layers, containing little 

 or no calcareous matter, have on that account, until lately, been re- 

 jected as useless, and sometimes when a bed of this description of 

 considerable extent was found immediately overlying a more shelly 

 stratum, much trouble and expense have been incurred in its re- 

 moval, to make way for the excavation of the material beneath. Ap- 

 pealing to the experience of the farmers of New Jersey, by whom 

 the greensand, in an almost unmixed condition, has long been ap- 

 plied for the purposes of a manure, its unrivalled efficacy, and the 

 permanency of its ameliorating effects, are to be regarded as estab- 

 lished and unquestionable facts. It is true, that at one time, owing 

 to the ignorance of those who attempted to make use of it, and the 

 application frequently of a spurious material resembling it in aspect, 

 doubts of its value have been excited in the minds of some; but the 

 extensive and uniform experience of the present enterprising farmers 

 of that state, gives an unqualified testimony to the rapidity, the 

 power, and the durability with which it acts. 



A comparatively small dressing of this marl, often not exceeding 

 ten or fifteen loads per acre, is uniformly attended with beneficial 

 results, and this, whether the soil to which it is applied, be a clay, 

 or a light sterile sand. As an illustration of this fertilizing property 

 of the greensand, I will subjoin the following statement quoted from 

 the report of my brother, Professor Henry D. Rogers, on the geology 

 of New Jersey, to which work I beg leave to refer, for ample and 

 satisfactory details relating to the agricultural value of this sub- 

 stance, as well as for practical suggestions as to the most judicious 

 modes in which it may be applied : 



" When we behold a luxuriant harvest gathered from fields where 

 the soil originally was nothing but sand, and find it all due to the 

 use of a mineral sparsely disseminated in the sandy beach of the 

 ocean, we must look with exulting admiration upon the benefits 

 upon vegetation, conferred by a few scattered granules of this unique 

 and peculiar substance. The small amount of greensand dispersed 

 through the common sand, is able, as we behold, to effect immea- 

 surable benefits in spite of a great predominance of the other mate- 



