148 GEOLOGY OF ILLINOIS. 



which, when free from mineral salts, by which it is sometimes deteriorated, 

 affords one of the very best materials for the manufacture of glass. 



Sulphur Springs. Springs containing sulphuretted hydrogen, occur in sev- 

 eral places in township 35, range 8, in the southeastern portion of the county- 

 One of the largest and best known of these springs, occurs on the land of Mr. 

 L. House, a little southwest of the center of section 15. It is a clear, constan- 

 spring, and gives off an odor of sulphuretted hydrogen, which is perceptible at 

 several yards distance, although the sulphurous taste to the water is not suffi- 

 ciently strong to render it disagreeable to most persons ; indeed, the reverse is 

 very often the case. It is much favored by picnic parties, and from various 

 relics which have been found in its immediate vicinity, it would seem to have 

 been used as a watering place by the aboriginal inhabitants of the country. An- 

 other similar spring, of less value, occurs close to Mr. House's residence, between 

 a quarter and a half a mile farther west, on the western bank of the creek, and 

 still others, in the southern part of section 23, and in the northeastern part of 

 section 16, in the same township. The formation in which these springs ap- 

 pear to have their source, id the Cincinnati Group. 



Peat. Small deposits of peat have been found in the prairie sloughs in va- 

 rious parts of this county, and also at one or two points along the Fox river, 

 but, with only one exception, so far as I am aware, they have not been tested 

 as to their extent or value as fuel. On the western bank of Fox river, in the 

 northeast quarter of section 4, township 36, range 6, there is a bed of this sub- 

 stance, which occupies an area of probably seventy or one hundred acres, or 

 even more, which has been used to some extent in the neighborhood as fuel, 

 and is reported to have made a good fire. This bed will, I think, average six 

 feet or more in depth, over the whole area which it occupies, and is probably 

 the most extensive deposit of the kind in the county. 



From the small fragments of stone coal, which are occasionally found in the 

 Drift and surface deposits in this county, some persons have been led to sup- 

 pose that coal beds might be found under the surface. In regard to this, it 

 can only be said, that there is no probability of the existence of any such beds 

 under any part of the county, excepting, perhaps, a very small area in the ex- 

 treme southwestern corner. It is possible, indeed, as has been stated before, 

 that small outliers of the Coal Measure strata may yet exist, under the Quater- 

 nary deposits in this region, and these might also be productive, but as we have 

 no certain knowledge of their existence, the chances are too hazardous to war- 

 rant any expenditure of labor or capital in their search. 



