120 GEOLOGICAL RECONNOISSANCE 
laxative in its effects; but it is doubtful whether its alterative effects will 
be as decided, since the proportion of sulphur appears to be less. As 
iodides are usually an accompaniment of chlorides, this water will proba- 
bly be found useful in reducing glandular swellings. bg 
At the blacksmith’s shop, near the sulphur spring, I saw several speci- 
mens of coal, found in this county, and obtained information in regard to 
the localities of others; viz., the Morrow coal, 14 inches thick, considered 
to be the best for blacksmiths’ use ; the Dyer coal, 12 inches thick, found 
on the second bench of the Boston mountain, which is a heavier coal than ~ 
the former, but contains impurities ; Barnet’s bank, about 11 inches thick, 
on the waters of Cove creek; and Store’s bank, three quarters of a mile 
beyond, and about the same ifickness as that at Barnet’s. 
On Cane hill, close by James Mitchell’s house, the Ar chimedes limestone 
is well exposed, and is quite cavernous. One cave, near Wm. Mitchell’s 
house, is about 180 feet long, and seems to have been the resort of bears 
and other wild animals, in former times. It occupies precisely the same 
position as the one which I visited near Orion Rieffs’. The succession of 
the rocks on Cane hill is only a modification of the preceding section. 
Fine-grained sandstone, 15 to 20 feet. 
. Limestone, a few feet. 
Coarse yellow sandstone, 40 feet. 
Greenish grindstone grit, 45 to 70 feet. 
. Archimedes limestone, 60 feet. 
. Marly shales in the bed of the branch. 
The blacksmiths of Boonsboro obtain a coal from section 16, township 
14 north, range 82 west, about three quarters of a mile from town ; ; itis 6 
or 8 inches thick: this is the most westerly outcrop of coal known in this 
county. 
Some iron ore is reported in Vineyard township, which I have not yet 
examined. 
A bold spring issues at Boonsboro, from under a bench of Archimedes 
limestone, 45 feet in thickness. The new College has been built on a 
commanding point on the shaly sandstones that occupy the hill, immedi- 
ately above the platform of limestone. Beneath these are dark shales, 
succeeded, in the descending order, by an even-bedded, brown freestone, 
very suitable for building purposes. The road to the Barren fork of the 
Illinois river passes for several miles on this building-stone, which, being 
often disjoined and displaced from the giving way of the underlying shale, 
renders the_road exceedingly rough. This underlying shale is of no great 
thickness, and overlies chert and cherty limestone, which forms a mural 
oP ere 
