On the Secondary and Tertiary Formations. 333 



acre, so that the surface of the fields is covered. Weeds are said 

 to be killed the first year, but to come up luxuriantly afterwards, 

 and clover appears spontaneously where none would grow be- 

 fore. In Caroline and Hanover counties, on land that would 

 yield only three barrels of corn (fifteen bushels) to the acre, from 

 ten to fifteen barrels have been obtained after one generous appli- 

 cation of the marl. On the Pamunkey river is a beautiful plan- 

 tation, regenerated from the old and exhausted tobacco lands ; 

 an example of what the Virginia soil once was, and what it may 

 be again, if treated with the skill and enterprise which charac- 

 terize Mr. WilHam Wickham, the proprietor of this place. He 

 has used the marl for eighteen years, applying it once profusely, 

 800 bushels to the acre. The bed here varies from ten or 

 twelve feet to not more than two or three. It is often cut 

 through, as if by a stream, and the space afterwards filled up by 

 the ferruginous sand which overlies the marl bed. 



In those tracts of country not cut through by large streams, 

 as Prince George county, the marl is obtained with great diffi- 

 culty, pits being dug that constantly fill up with water, which 

 cannot be kept out even by expensive pumping. Still it is in 

 great demand, the planters digging it in the winter months, 

 when their hands are least occupied, and then carting it over the 

 fields, where it lies in heaps ready to be spread in the spring. 

 The lands in this county are generally stiff and clayey, and 

 would be benefitted by a free application of common sand, as 

 well as of the marl. From these heaps I collected a great variety 

 of fossil shells, enough to show that the deposit belongs to the 

 same formation with that which I afterwards traced through North 

 Carolina, but the specimens never have arrived from Murfrees- 

 boro', N. C, where I left them. This is the case also with many 

 I collected at Murfreesboro', on the south side of the Meherrin 

 river. Some brooks have cut deep into the sand hills on which 

 the town stands, and have distinctly exposed the marl ; while from 

 the bed they have washed out a profusion of fossil shells, chiefly 

 Pectens and OstreEe. Not far above the marl is a stratutn of stiff, 

 red clay, alternating with layers of sand. A bed of this character 

 I have noticed in a similar position throughout a great part of the 

 southern states ; at Richmond, Va., it is very conspicuous near the 

 summits of the hills, as well as in the southern part of Sumpter 

 district, S. C. ; and in many places in Georgia, near the Savan- 

 nah river, it is well exposed. It is accompanied by white clay, 



