of former animal occupation, it being found in the form of
effervescenses on the walls. Dr. Shumard mentions several of this
character in Pulaski County, the most noted being Niter Cave, in the
Third Magnesian Limestone, with a wide entrance thirty feet above the
level of the Gasconade. On page 201, he also gives a charming
description of one of the immense springs that are numerous in this
region and that I have never seen elsewhere. He says:

"Ozark County is bountifully supplied with springs of the finest water,
and some of them of remarkably large size. The largest one is situated
near the North Fork, in T. 24, R. 11 W., Sec. 32, and is known under the
name of the Double Spring. It issues from near the base of a bluff of
Sandstone and Magnesian Limestone, a few feet above the level of the
North Fork. This spring discharges an immense volume of water, which is
divided by a huge mass of Sandstone into two streams, with swift
currents flowing in opposite directions to join the North Fork about one
hundred and fifty yards distant from the spring. I estimated the width
of these streams at not less than fifty yards. They are separated from
the North Fork by a pretty wooded island one hundred yards long. The
upper stream affords a good mill-site. I am informed that the quantity
of water discharged by this magnificent spring is not materially
diminished during the dryest seasons of the year. The temperature of the
water measured at the edge of the spring, was found to be 56 deg.; the
temperature of the air at the same time, 59 deg. Other springs of
considerable magnitude occur in various portions of the county, giving
rise to beautiful and limpid streams."

The descriptions of the Natural Bridge and Friede's cave, near Rolla,
previously referred to as being on page 16 of the same volume, are as
follows:

"On Clifty Creek found the chert bed of Sec. 21-5 occurring about sixty
feet from the top of the Third Magnesian Limestone, with a road passing
over its upper surface, presenting it very favorably for observation. It
seemed here to be broken by vertical cracks into large rhomboidal
blocks. Further up this creek in a wild and secluded spot, observed a
Natural Bridge with six feet of this chert bed at its base, and
Silicious Magnesian Limestone above. The span of this bridge is about
thirty feet, an elevation of opening about fifteen feet above the water,
the thickness of the rock above is about twelve feet, and width on t