Gooch and Danner — Interaction of Potassium, etc. 301 



north-flowing streams. The lowlands north of Cayuga lake 

 (Montezuma marshes) offer a very slight barrier to such a dis- 

 charge. It is worth noting that a boring made at Geneva, at 

 the lake side, encountered obstacles from bowlders at about 

 100 feet, and struck no true rock until 240 feet below the 

 water line. A valley three miles wide between existing rock- 

 exposures, and 300 feet deeper than the present lake surface, 

 apparently opening to the north, is indicated at Geneva : some 

 of this depth may be ascribed to glacial action. 



Section of Channel of Wisconsin River (Report of U.S. Geol. Sur., VI, p. 230) 

 partially filled with river-gravel ; compared with that of Seneca Lake at deepest 

 point. The latter section is adapted to scale from that given on the map pub- 

 lished by Cornell University; the dotted slope of bank is obtained from contour- 

 lines of map. Ratio of vertical to horizontal scale nearly = 10 : 1. 



The accompanying cut is given to show the contrast between 

 the much-glaciated banks of Seneca Lake, with thin smooth 

 gentle curve leading to the upland levels, and the unglaciated 

 banks of the Wisconsin River, falling at a sharp angle from 

 the level of the plain in which the valley is cut. The section 

 is from one of the narrower parts of the river, in its course 

 through the non-glaciated region. The river valley is filled to 

 an unknown but considerable depth with material brought 

 from glaciated territory. The lake valley, judging from the 

 outline given, is free from heavy glacial or postglacial deposits 

 for many miles ; its ends, however, are deeply tilled. 



Art. XXXIX. — On Certain Points in the Interaction of Po- 

 tassium Permanganate and Sulphuric Acid / by F. A. 

 Gooch and E. W. Danner. 



[Contributions from the Kent Chemical Laboratory of Yale College — XVII.] 



In an article published some years ago by Mr. Francis 

 Jones* upon the action of reducing agents upon potassium 

 permanganate the statement is made that in the interaction of 



* Jour. Chem. Soc, xxxiii (1878), p. 95. 



