383 



of Wayne county. Probably many of the clays may be found ap- 

 proaching so nearly to marl, as to be of great value as a stimulant ma- 

 nure to sandy soils. 



SULPHUR SPRINGS. 



T^vo miles below Monroe, near the marshy border of tlie Lake, sev- 

 eral springs issue from an immense mound. They are strongly im- 

 pregnated with sulghur, and form thin white deposits of that substance. 

 This mound occupies an area of 4 to 6 acres, rising about 10 feet above 

 the general level. Its surface is wet and boggy. This mound is evi- 

 dently a deposit from the water of the springs, which running through 

 crevices in the great underlying rock formation, becomes highly charged 

 with lime, and on approaching the surface deposits that substance either 

 in a soft plastic mass, or as a coating upon the moss and surrounding 

 vegetation. Thus marl and tufa result. This process may be observed 

 now going on. Large quantities of moss, still alive, are covered with 

 a thin calcareous crust. A mile fuither south, are numerous smaller 

 mounds of similar origin. One of these discharges a considerable stream 

 from a spring occupying a large cavity in the centre. Here a foot 

 thickness of white marl is disclosed, overlaid by two feet of crumbling 

 tufa. The spring boils up through a cauldron of calcareous and vege- 

 table matter, into which a pole may be thrust many feet. This mound 

 is circular, 1 00 feet diameter, and 6 feet high. Most of the other 

 mounds consist of a very indurated lime, or tufa. 



The famous sulphur spring in the Bay settlement, emerges from a 

 low mound of similar formation, situated in the edge of the large marsh 

 bordering the bay. It occupies a circular basin of 150 feet diameter 

 by 45 deep. A stream flows from it which at its head is 10 feet wide 

 and 3 deep, and has a considerable current. The odor of sulphur may 

 be perceived at distance of half a mile, though the water is not of 

 extraordinary strength. A bathing-house was in contemplation at this 

 place, but the unusual rise of the lake caused an abandonment of the 

 project. 



Springs occur in great numbers on Sulphur creek, town of Lasalle. 

 They occasion mounds of the same character as those near Monroe, and 

 discharge considerable streams. A few of those united, formerly sup- 

 plied a mill. 



