OF SOUTH CAROLINA, 215 
2. Strongest clay soil, consisting of clay mixed with 15 to 30 per cent of sand. 
3. Clay loam, containing from 15 to 30 per cent. of sand. 
4. Loamy soil, has from 30 to 60 per cent. of sand. 
5. Sandy loam, from 60 to 90 per cent. of sand. 
6. Sandy soil, contains only about 10 per cent of clay. 
To determine the place that a soil should occupy in this classification, all that is necessary is to 
separate, by washing, the fine particles froma dried and weighed portion, allowing the sand to 
subside, and weighing it after being carefully dried. 
Thaer and Schwertz arranged another scale, founded upon the products of the different soils, and 
having, like the preceding, sand and clay at the zero points. The soils meet in the centre of the 
scale, in one which will produce all kinds of grain. 
The scale is arranged in the following manner : 
0. Moving sands, 0. Stiff clay, 
1. Rye land, 1. Wheat land, 
2. Rye and buckwheat land, 2. Wheat and oat land, 
3. Rye, buckwheat, and oat land, 3. Wheat, oat, and barley land, 
4, Rye, oat, and small barley land, 4. Wheat and large barley land, 
5. Wheat, rye, barley, and oat land. 
The species of soil adapted to these crops are— 
1. Light dry sand, 1. Cold, stiff clay, 
2. Moist, very slightly argillaceous land, 2. A lighter moist clay, 
3. Argillaceous sand, 3. A warm dry clay, 
4, Sandy clay. 4. Rich clay. 
5. Clay. 
These examples will, perhaps, be sufficient to give a clear view of what is meant by the classifi- 
cation of soils. 
Besides the mineral and other constituents of soils, there are certain physical properties that must 
be taken into consideration, as conditions of fertility, scarcely less important than the chemical com- 
position of the soil. 
They are—the specific gravity of the soil; power of imbibing moisture ; tenacity, or resistance 
presented to the plough; disposition to become dry ; shrinking and drying; hygrometric property 
of soils; absorption of oxygen by the soil; capacity of soils for heat; and the degrees in which 
soils become heated in the sun. 
For the ingenious investigation of these properties we are indebted to Schubler. The following 
tables are drawn up from Bousingault’s account of his experiments. 
Specific gravity.—It appears that silicious and calcareous sandy soils are the heaviest, and 
clayey soils the least in density; that humus, or mould, is lighter than clay; and that, conse- 
quently, a compound soil will be of greater or less density, as either of these prevails. 
Power of imbibing moisture—This is a highly important property of a soil, particularly in rela- 
tion to climate. Every thing else being equal, in a warm, dry climate, a soil possessing this prop- 
erty in a high degree, will exhibit a decided superiority. This property is estimated comparatively, 
