OLD VIEWS OF MARL OP VIRGINIA. 399 



usual admixture of sand or clay. I have worked a particular layer 

 nearly as pure, and which had the same disadvantage of water 

 pouring in through the very open texture of the broken shells. 

 There is an extensive bed of as pure and unmixed fossil shells, near 

 to the surface of the earth, and there quite dry, near the northern 

 limit of sea-coast of South Carolina.* 



45. The next evidence is from a report of the Rev. John 

 Clayton, Rector of Crofton, in Yorkshire, to the Royal Society of 

 England, in 1688. The writer visited Virginia, and this was the 

 report of his personal and somewhat scientific examinations. It 

 was republished in the 4th vol. of Farmers' Register. The writer 

 saw, with astonishment, and describes the beds of fossil shells in 

 the river cliffs and though with much looseness and inaccuracy, 

 still there is no doubt that he included in his observations not only 

 the actual beds of loose oyster shells, but the petrified oyster shells in 

 other places, and also the beds of other and various fossil sea shells, 

 which since have obtained in Virginia the provincial term of marl. 

 For though he oalls all of them " oyster shells," it is manifest that 

 he also referred to the sea shells, as he particularly describes the 

 "shark's teeth" and large vertebra which are so common in these 

 beds, and never known in the deposits of oyster shells alone. Now 

 this gentleman, from his residence, and his information, could not 

 possibly have been ignorant of marl in England. Yet in all his 

 remarks and speculations (some very wild), on these beds in Vir- 

 ginia, he does not call them marl, or refer to any similarity of these 

 beds to marl nor even suppose any use for ours, other than that 

 before known, of burning the shells to make lime for cement. (See 

 Farmers' Register, vol. iv., pp. 642-3.) 



From all the foregoing quotations and evidences, I claim that 

 the propositions enumerated in the beginning of this article, have 

 been sustained fully; and that the following deductions must neces- 

 sarily be made : 



1. For centuries after marling had been recommended by Eng- 

 lish books on agriculture, and extensively practised by very many 

 farmers of England, it was not generally, if at all, understood by 

 either writers or farmers that calcareous earth was the all-important 

 or even an essential ingredient of marl, as a manuring agent ; and 

 many clays used for and as marl, certainly contained no carbonate 

 of lime. 



2. Though more lately, English writers have taught correctly 

 that marl is calcareous, and also (generally) that the value of the 

 manure depends mainly on the lime contained, still the previous 



* Described in the supplement to my Report of the Agricultural Survey 

 of South Carolina. The deposit is on and near Price's creek, in Horry aud 

 is of the post-pliocene division. E. E. 



