NOKTH-CAROLINA GEOLOGICAL SURVEY. 105 



I mentioned in my last letter to you the effect that marling, or ditching, 

 or both combined, had had upon the health of this place. I told you that 

 this plantation was remarkably sickly previous to the fall of 1855 so much 

 so that it was strange for even one to escape billious, or ague and fever. I 

 mentioned that in 1855 there was not a case of either, in 1856 but one, 

 and now I will add that so far this fall, in a family of forty persons, there 

 has been but two cases. (I happened to have been one of the subjects.) 

 These three falls have been dry. I don't know how a wet one would act 

 upon us. I have kept marl plentifully used in my yard, and around and 

 in my negro houses. 



I shall be under many obligations to you for analysis of my marl. 



Yours, &c., 



W. B. WADSWORTH. 



76. A marl belonging to the same epoch, (eocene) fur- 

 nished by J. H. Haughton, from his plantation in Jones 

 county, gave me 56.06 per cent of carbonate of lime. An- 

 other specimen gave : 



Silex or sand, 13.00 



Phosphate of peroxide 'of iron and alumina, 1.10 



Carbonate of lime, 85.2C 



Carbonate of magnesia, 1.02' 



Potash, 0.02 



100.34 



I have found in these white marls a small per centage of 

 potash. It is evidently less than in the other varieties. This 

 is made up like the Wadsworth marl, of fragments of fossils, 

 in which certain species of corals and a crinoid abound. 



A variety is met with which is derived from the disinte- 

 gration of a large species of oyster. It occurs upon the plan- 

 tation now owned by L. Haughton, Esq., and is known as 

 the Pollock place, in Jones county. It contains : 



Carbonate of lime, 34.54 



Sand, 63.46 



Peroxide of iron and alumina, 1.30 



99.30 



Large grains of sand are distributed through the marl. It 



