STATE IIORTICILTI RAL SOCIETY. 81 



Strata, and the hills were covered with a meagre growth of yellow pine 

 and scrub oak timber. The farms consisted of the small patches of level 

 land in the valleys of the streams, and the main products were corn, 

 sweet potatoes, and small patches of tobacco for home consumption. 

 Before reaching the Tennessee river, however, we struck the belt of lower 

 carboniferous limestone that surrounds the coal field, and the change 

 observable in the general character of the country, and the products of 

 the soil, was quite remarkable. Here the hills were less abrupt, and the 

 general surface more gently rolling, and originally covered with a magnifi- 

 cent forest of oak, ash, elm, cedar and sugar maple. The tilled land 

 was exceedingly productive, yielding fine crops of cotton, tobacco, hemp, 

 corn and other cereals, with all the fruits of the temperate zone in great 

 perfection. 



Passing on through Tennessee and Kentucky, similar changes were 

 observed in crossing the various subdivisions of the Silurian and Devo- 

 nian systems; those composed mainly of sand producing a thin, poor 

 soil, and the clay shales a tenacious soil, while the limestones and calca- 

 reous shales usually gave origin to a soil of excellent quality, of which 

 that of the famous blue-grass region of Kentucky is an example. These 

 soils have been termed soils of immediate derivation, as distinguished 

 from those predicated upon material that has been transported from a 

 distance. But possibly some of my audience may inquire how or by what 

 methods are the solid rocks transformed into fertile soils, fitted for the 

 production of everything necessary for our subsistence, and the existence 

 of the myriads of animals and plants that are directly dependent upon it 

 for their being. No doubt many of you have solved this question for 

 yourselves, as it is by one of nature's simplest processes, one that has been 

 going on ever since the solid rock was formed, and will continue until 

 the present order of things shall come to an end. If we could find an 

 area of naked rock with a nearly level surface, and should observe it 

 closely for a few years, we should witness something like the following 

 phenomena: 



After an exposure of a k\v years, more or less, according to the 

 hardness of the rock, whether it was limestone, sandstone, shale or solid 

 granite, we should observe that the action of frost and moisture upon the 

 naked rock surface had gradually loosened and finally separated particles 

 of the rock therefrom, the particles remaining loosely, in the form of sand 

 or clay, upon it. Lichens and mosses would be found growing upon it, 

 and to these would soon be added other plants and grasses ; tliese would 

 furnish a shelter for insects, and the latter would attract the birds, and 

 thus a certain amount of organic matter would be added to the disinte- 

 grated mineral substances the rock afforded. Then, as this process of 

 accumulation went on, the seeds of shrubs and finally of trees would take 

 root upon it, and in due time the entire surface would be transformed 

 from a naked rock into a more or less fertile soil, covered, perhaps, by a 

 dense forest. If the rock surface was originally an uneven one, then the 

 accumulation of soil would commence in the valleys or depressions, and 

 gradually extend from thence until the whole was covered. The action 



