1685, 686,687] analyses of "loam" and "silt". 317 



the surface to washing by rains; and the line between it and the overlying loam 

 is often very sharply defined by a backward slope, formed by the brown loam 

 which is carried away freely by rains and freezes. Finally, its presence on or 

 near the surface is indicated by the frequent occurrence, among the timber above 

 described, of the " Poplar", Sweet Gum, Magnolia, Mulberry, Linn, Honey 

 Locust, and on the lower portion of the slopes, the Red Haw, Crab Apple, and 

 Sycamore. Above all, the (Jane is significant of its presence. Although at pres- 

 ent, the cane on the hills has mostly been destroyed by cattle, it may sometimes 

 be seen in protected spots, covering them from the foot to the summit — as was 

 the case generally before the country was settled. 



The trees but just mentioned, and among them particularly the "Poplar", 

 Linn, and Sweet Gum, not unfrequently occupy the ground completely, to the 

 almost entire exclusion of the oaks. The Beech, Horn Beam, and Holly, how- 

 ever, are nearly wanting. 



685. The three specimens from this region, which have thus far been analyzed, 

 were selected with a view to obtaining results fairly comparable, and repre- 

 senting as nearly as possible, the average composition of both kinds of soil. 

 They were, therefore, taken on one and the same piece of ground, in different 

 spots, on the land of Mr. James Watson, about five and a half miles north-east 

 of Port Gibson, on the Raymond road. Here the brown loam is from eight to 

 ten feet thick on the hilltops ; in the cuts on the hillsides, the calcareous silt 

 appears and approaches nearest to the surface about half way down the hill, the 

 lower portion (" talus ") of which is again formed by brown loam differing little, 

 in its appearance, from that on the hilltops ; but having evidently been washed 

 down from above, it probably contains an admixture of the calcareous silt. 



68G. The specimens of soil and subsoil were taken on the hilltops, and a speci- 

 men of silt in the cut on the hillside, a few feet below the surface. 



No. 332. Upland Surface Soil from J. Watson's place, five and a half miles 

 north-east of Port Gibson, Claiborne county. 



Depth : Eight inches. 



Vegetation : That mentioned above, in the general description, (1T684 1 .) 



The soil, rather light, of a buff color ; much less clayey than the loam sub- 

 soil. Saturated with moisture at 68.0 deg. Fahr., lost 5.182 per cent, at 400 

 Fahr. Dried at this temperature, it consisted of: 



Insoluble Matter 87.573 



Potash 0.458 



Soda 0.124 



Lime 0.244 



Magnesia 0.545 



Brown Oxide of Manganese 0.205 



Peroxide of Iron 3.231 



Alumina 4.842 



Phosphoric Acid 0.105 



Sulphuric Acid 0.028 



' Organic Matter and Water 3.073 



100.429 



687. No. 233. Upland Soil from J. Watson's place, five and a half miles 

 lorth-east of Port Gibson, Claiborne county. 



Depth ; Eight to twenty inches. 



Vegetation : Same as the preceding. 



A yellowish-brown loam, much heavier than the surface soil. The subsoil, 

 saturated with moisture at 68 deg. Fahr., lost 9.22 L per cent, at 400 deg. Dried 

 tt this temperature, it consisted of: 



