682 GEOLOGY OF OHIO. 
its weathering has given rise to the thin stratum of soil that now covers 
it. MHxamples of this sort may be seen on Reed’s Hill, in Bath township, 
where the weathering of the Clinton limestone has furnished a very pro- 
ductive but shallow soil to quite a number of acres. Along the boun- 
dary of the Lower and Upper Silurian formations, again, little patches : 
of these native soils are to be seen, as at Goe’s Station, in Miami town- 
ship, and on the tarms of Franklin Berryhill and Thomas J. Brown, of 
Sugar Creek township; but the aggregate of all such cases is insignifi- 
cant, and the statement that the soil of the county is derived from the 
Drift scarcely requires qualification. 
There is a very important sense, however, in which the soils of Greene 
county may be said to be native soils. Naked beds of bowlder clay are 
no more soil than are raw shales or quarry spalls. All can be converted 
into soils by sufficient exposure to atmospheric influences. In point of 
fact, the shales that constitute so large a part of some Ohio formations, 
and notably of the Cincinnati series, are converted into soils far more 
rapidly than the bowlder clay. The soils of the county, then, have been 
formed where we find them by the same slow processes that are required 
to transform a stratum of limestone rock into soil. It is principally by 
the process that is termed “ weathering” that the stubborn and imper- 
vious clays of the unaltered Drift are changed into the porous, light, and 
permeable layer that we call soil. The action of the atmosphere can be 
easily traced in such cases. There are always present in our Drift clays, 
grains, pebbles, and bowlders of limestone. In southern and central 
Ohio they constitute by far the largest proportion of the rocky fragments 
of the Drift beds. But limestone is soluble in rain and surface water. 
These fragments, then, both small and great, are slowly dissolved, their 
lime being carried away in drainage water, while the sand and clay and 
iron which made a part of their substance are left to contribute to the 
soil. Similar changes go on in other substances in the Drift bed, and 
the results of all are to open these stubborn clays to air and water, to 
change their color, to alter their texture, and thus, also, to alter their 
specific gravity. The incorporation of vegetable matter with the forming 
soil goes on through all the stages of its growth. Until the proportion 
of such matter reaches at least 5 per cent. of the whole mass, the clay is 
scarcely to be called a soil. 
But in the final stages of its preparation, to another division ai the 
living creation a very important office is assigned, one, however, which 
is seldom estimated according to its real value. The insect kingdom, 
beetles, ants, earth-worms, etc., bring up from below the surface, for very 
different objects in the econmy of their several existences, particles of 
