68 
THE SOIL OF THE COTTON STATES. 
No. 4. 
Surface Soil from Samtjiel Wood's plantation^ in Hamock 
County^ Mississippi. 
One hundred parts by weight of this soil yielded — 
Silica 88.52 per cent. 
Alumina 1.20 " 
Lime 0.40 " 
Magnesia 0.50 " 
Potash 0.38 " 
Soda 1.00 " 
Peroxides of iron and manganese. . 2.00 " 
Phosphoric acid 0.60 " 
Sulphuric acid (less than xrsr) trace. " 
Chlorine trace. " 
Crenic, apocrenic, and humic acids. 0.92 " 
Carbonic acid . €.20 " 
Insoluble vegetable matter 4.33 " 
100.05 
One thousand grains of this soil yielded to boiling dis- 
tilled water two grains of soluble matter, or one-fifth of one 
per cent., and this, on incineration, yielded half a grain of 
ash, or five-hundredths of one per cent. The ash consists 
of phosphate of lime, magnesia, oxide of iron, sulphate 
of lime, and the alkalies, potash and soda. 
Digested in a solution of carbonate of ammonia, one 
thousand grains of the soil produce a dark cofFee-brown 
solution, which, evaporated to dryness, yields ten grains of 
soluLle matter, consisting of the organic acids of the soil, 
namely, crenic, apocrenic, and humic acids ; and on being 
burned off, this matter yields four-fifths of a grain of ash, 
