8 ADVANTAGES OF KENTUCKY. 



Professor Shaler states (Rep. Ky. Geol. Sur., N. S., Vol. Ill, p. 208): 

 "I have not been able to find in this Commonwealth any trace of ancient 

 gravels which have come from north of the Ohio, the whole evidence 

 going to show that there has been, within the time that a granite boulder 

 can endure near the surface, no glacial action that could bring the north- 

 ern drift any distance south of the Ohio." 



To these fortunate geological conditions, therefore, are our Kentucky 

 soils greatly indebted for their fertility and for the extremely fine state 

 of division of their constituent particles. In the great majority of these 

 soils analyzed by the present writer, the silicious particles, left after 

 digesting the soils in chlorohydric acid, of specific gravity 1.1, all passed 

 through a fine sieve, which had sixteen hundred meshes in the cen- 

 timetre square. All scientific writers on soils attach the greatest impor- 

 tance to the relative fineness of the particles which form them. Mons. 

 DeGasparin {"Terres Arables" yne. ed., p. 33) says: "It must not be 

 forgotten that the nutritive power of a soil, other things being equal, is 

 in direct proportion to the fineness of the particles which compose it; " 

 so much so, indeed, that when a soil is to be chemically analyzed, only 

 the "fine earth," or that portion which will pass through a sieve having 

 ten wires to the centimetre, is taken for the analysis, the coarser part 

 being considered practically inert as to plant nourishment — only a skele- 

 ton, which is not to be taken into account when estimating the fertility 

 of a soil; and this is especially true when the coarser particles are of 

 quartz, or some hard silicate not readily to be disintegrated or decom- 

 posed by the ordinary process of weathering, or which do not contain 

 any essential element of plant nourishment. 



In this important particular our Kentucky soils are more valuable 

 than the great body of those of the great Northwest: that not only are 

 their constituent particles very minutely divided, but even these, fine 

 enough to pass through the meshes of the finest seive above described, 

 are not entirely fine sand of silica, but contain a considerable propor- 

 tion of fine particles of decomposable silicates, which in the process of 

 weathering help to keep up the supply of essential plant food, and make 

 the soils very durable. In some of his analyses of Kentucky soils the 

 writer has found as much as 2.9 per cent, of potash in the fine silicious 

 residue of a soil which was left after a week's digestion in diluted 

 chlorohydric acid, but which would gradually be unlocked and made 

 available for plant growth under the influence of time and the atmos- 

 pheric agencies. 



