158 Geology of Upper Ilinois. 
It is certainly a circumstance which considerably enhances the 
value of these springs, that one of them is a sulphureous bape 
while the other two are saline only. Their effects on the 
economy will undoubtedly be different, and a much larger class 
of invalids may therefore resort to them with advantage. As the 
country of the Upper Illinois has been settled only a few years, 
of course nothing has been ascertained from experience with re- 
gard to these waters; but from what is known of the constitution 
of the Virginia springs, it may fairly be presumed, that the use of 
of these waters will be attended with the same beneficial results, 
as are experienced at some of those celebrated resorts. The Illi- 
nois springs occurring, moreover, in a region distinguished for the 
beauty of its scenery, and lying directly on one of the greatest 
thoroughfares in the west, must also have their value much en- 
hanced from these considerations.* 
The springs in the bed of the Vermilion, at Vermilionville, (O,) 
are sulphureous in their character ; and at the same time, equally 
rich in saline matter with the iliziots springs.t 'They are unfor- 
tunately so situated, however, as to make it difficult to obtain 
a supply of the water they afford, since their points of issue are 
completely overflowed at high stages of the river. The spring 
at Ottawa is simply a saline water. I had no opportunity of test- 
ing its ingredients, but should judge from its taste that it will be 
found to resemble in constitution, the main. spring on section 
twenty-three. 
A still more valuable resource to the country is fully indicated 
by the composition of these springs, and the circumstances under 
which they occur. The large and constant proportion of chloride 
of sodium they contain, taken along with their occurrence in a 
region of coal, sandstone, and red marl, leaves no room to doubt, 
that borings of a suitable depth will load to the supply of a strong 
and pure brine well adapted to the manufacture of salt. Nor 
need any apprehension be felt at the detection of so many foreign 
substances in the waters of the existing springs, since these will 
be replaced by chloride of sodium, in the supply to be expected 
* That they were frequented in former times by the deer and the buffalo, is P- 
parent from the remains of the skeletons of these animals found buried in the 
in their immediate vicinity. 
+ T examined these waters on the spot, and subsequently a a5 of them con- 
densed by evaporation, which was furnished me by Dr. Hat 
