50 BOARD OF AGRICULTURE. 



deposits in company with Col. Hatch, and with every pros- 

 pect of success, when the outbreak of the Rebellion put a stop 

 to operations. But it was known that the underlying marl 

 was unusually rich in phosphate, sufficiently so to make it 

 compare favorably with the New Jersey marl, and to estab- 

 lish it as a valuable fertilizer. 



As early as 1842, Edmund Ruffin, of Virginia, was appointed 

 to make a scientific survey of South Carolina, for the purpose 

 of developing its mineral resources. At that time the public 

 attention was fixed upon marl as the great regenerator of the 

 soil, and as the nodules of phosphate rock were found to con- 

 tain only a small amount of carbonate of lime, they were 

 passed by as worthless. Even those who suspected some 

 hidden value in these rocks, and had taken pains to pound 

 them up to spread over the land, were discouraged from 

 doing so. This is not, perhaps, to be wondered at, when it 

 is considered that artificial fertilizers, superphosphates and 

 guano, were at that time comparatively little known in this 

 country. The leading idea was to develop the immense beds 

 of calcareous marl that were known to exist in South Caro- 

 lina and Georgia. 



The carbonate of lime, though possessing some agricult- 

 ural value, is comparatively inert. Marl is a compound of 

 earthy mixtures, of which carbonate of lime in any form con- 

 stitutes either the sole or the chief value as a manure. To 

 be of much value it must be rich in carbonate of lime and 

 sufficiently soft to be excavated or broken down by ordinary 

 digging utensils. It is usually formed of the shells of mol- 

 lusks and other marine animals of a former age, broken 

 down or finely comminuted by the action of the elements 

 and natural causes, and often cemented by clay, or closely 

 compacted and hardened by the presence of superincumbent 

 masses of earth, the action of water or otherwise. It usually 

 contains numerous fossils. Most marl-beds are fossiliferous. 



Immense marl-beds underlie the layer of phosphate rocks 

 throughout the whole South Carolina basin, averaging in the 

 aggregate about seven hundred feet or more. These beds 

 belong to what may be called recent geological formations, 

 though the different strata differ in age. First below the 

 phosphate rock, and separated from it only by a thin layer or 



