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that of sand in which this soil differs from ordinary produc- 

 tive soils, known as clayey loams, and which renders it a very 

 light one, of little tenacity, or of retaining powers for water, 

 and nourishment in general, but this condition is also due to 

 the nature of the cement itself, winch does not show a proper 

 quantitative proportion of its constituents. These constituents 

 ought to be united to each other in such a proportion, that 

 none of them can exercise a predominent influence. Sand, 

 lime and magnesia, on one side, have to temper the tenacity 

 and binding of the clay, iron, and humus, and by these means 

 permit the free influence of the air upon the soil, and the 

 rain water to penetrate it intimately without resting upon it. 

 Clay, iron, and humus, on the other side, have to exercise 

 their binding and water-reserving powers, but only to such 

 an extent as will retain the solution of nourishing substances 

 without doing injury to the porosity of the soil or its commu- 

 nication with atmospheric ingredients. 



An examination of the cement of the soil in question, shows 

 no such quantitative proportion of its constituents. It is 

 almost entirely composed of sand, and peroxide of iron, next 

 to those of clay, then of magnesia and humus, and only of 

 such small quantities of lime as is quite common in soils. It is 

 most probably to this fact that the larger per centage of mag- 

 nesia must be attributed, which we meet in the composition 

 of the ash of the cotton fibre, and especially in that of the 

 seeds raised upon this soil. The want of lime induced the 

 cotton plants to appropriate more abundantly magnesia, a 

 substance which, in its chemical character and properties, 

 stands nearest to lime, and which, therefore, is capable of sub- 

 stituting it to some extent. It is, however, beyond doubt 

 that a substitution of lime by magnesia, induced by circum- 

 stances of necessity as they may have occurred here, will 

 rather act injuriously on the quality of the fibre than improve 



