32 WISCOXSIK ACADEMY SCIEJq'CES, ARTS, AND LETTERS. 



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There are several shoals with from two to six feet depth of water. 



There is no deposit of mud or sand brought into the lake by the 

 river; the water-supply both from the river and from the numerous 

 springs on the shore, being always clean and pure. One of these 

 springs on the south shore, known by its Indian name Minnewoc, 

 (place of waters,) has been analyzed by Mr. G. Bode, of Milwaukee, 

 Chemist of the Wisconsin Geological Surve}^ with the following 

 result: 



Chloride of sodium . 129 



Sulphate of soda . 627 



Bicarbonate of soda 1.041 



Bicarbonate of lime ■ 9 . 638 



Bicarbonate of magnesia 6 . 138 



Bicarbonate of iron . 129 



Alumina 0.067 



Silica i 0.879 



Total (grains in one gallon) 18 . 648 



It will be seen that the chief ingredients, as in most Wisconsin 

 waters, are lime or magnesia, derived doubtless directly from the 

 magnesian limestone rocks and pebbles buried beneath the soil. 

 This analysis also shows that the water does not differ essentially 

 from those having great reputation for their medicinal virtues. 



The lime from the springs is deposited, under favorable circum- 

 stances, upon the bottom of the lake forming beds of pure white 

 marl; a process which is materially assisted by the secretions of 

 mollusks aud aquatic plants, especially the chara and algas. 



The temperature of the water, being an important item in fish 

 culture, was taken at different times near the surface, where it had 

 considerable depth, with the following result: 



In May 41« Fahr. 



In June 63 " 



In July ,. 72 " 



In August 72 " 



In September ^ 72 " 



In October, 1874 53 " 



An attempt was made to find the temperature at the bottom in 

 deep water and resulted in showing at soaie times no' differences, at 

 other times one or two degrees warmer or colder; though the deep 



