294 | SS \GEOLOGY .OF. OHIO. 
only remains to inquire what is the origin of this acid, and how it can 
be removed from the soil, or have its injurious properties neutralized. 
The underlying rock is the Huron shale, which is filled with nodules and 
concretions of the bi-sulphide of iron. Wherever this is exposed to the 
joint action of air and water, it is decomposed, the sulphur set free, and, 
uniting with the oxygen of the air, produces sulphuric acid. These 
changes are facilitated by cultivation, and by more perfect drainage of 
the soil, so that the steps taken to improve the soil only aggravated the 
evil. If this-is the cause of the difficulty, the remedy is easily found— 
a generous dressing of sashes, or of quicklime, will be sufficient. The 
ee uniting with the acid, will form sulphate of lime, or “plaster,” of 
tself a good fertilizer. The alkali must be well mixed with the soil, 
and the application may have to be "repeated, until all the pyrites within 
reach of atmospheric influences, has decomposed, and yielded up its sul- 
phur. In a similar case, in Trumbull county, a single application, made 
gomie ten or twelve years 220, was sufficient to neutralize the acid, and 
no repetition of the remedy has been required. The amount of lime 
needed: can only be learned by experiment. As the railroad, from San- 
dusky, where there is an abundance of limestone, passes directly through 
these “bad lands,” they can probably be rendered Sook at comipar- 
atively little expense. ; | 
Hast of Norwalk the sand ridge has a ae waving contour on the 
north, and is bounded by a.broad water plain, except as modified by 
recent erosion. On the.south it is very irregular in its outline, the bil- 
lowy round dunes being of varying : height and form, and often extend- _ 
ing a long distance from the ridge. The materials of the ridge are, at 
the top, finely washed sand, resting upon gravel, with a profusion of 
granite bowlders, and below this, bowlder- elay or bed-rock. This is the 
only well- marked and continuous sand ridge in the county, a winding 
highway, thrown up by the action of the waves, resting in places directly 
upon the bed-rock, in others upon the coarser materials of the Drift clays, 
sometimes burying beneath it the debris of the old shore swamps, and at 
others extending over chasms one hundred or more feet in depth, filled to 
the general level with drifted material. The deep ravines in the bed-rock, 
now filled with Drift, and the eeneral contour of the rock surface here and 
in other parts of northern Ohio, indicate a peculiar topography before the 
period of the Drift, viz., a broad expanse of rock surface, disintegrated in 
places sufficiently to'form a soil fitted for the support of forest trees, with: 
a net-work of deep channels, which are now filled with Drift, but which | 
largely determined the location of the present lake chains and river courses. 
Granite bowlders of. various sizes may be occasionally seen projecting 
