44 Wisconsin Academy of Sciences, Arts and Letters. 



Of the copper in Illinois we have somewhat fuller notes, 

 though not more detailed. In this state, drift copper reaches , 

 its southern limit, so far as now known. In Saline county, 

 near Gallatin, latitude 37° 40', a nugget " larger than a hen's 

 egg," with not infrequent smaller ones, have been found by 

 Dr. Smith, and noted by Prof. E. T. Cox, then of the Illinois 

 Survey, in the beds of streams and in ravines.' The same is 

 true of Hamilton county, lying just north. 



Prof. Worthen has noted the existence of copper in the 

 drift of Clark and Cumberland counties,' and Mr. F. H. 

 Bradley in Edgar, Champaign and Ford counties, lying 

 just to the north. In Vermillion county, still further north, 

 the same authority ' says that several large masses of cop- 

 per, and many small ones have been taken from the upper 

 drift beds, The occurrence of copper in Hancock, Adams, 

 Brown * and Schuyler ' counties has also been noted by Prof. 

 Worthen; and in Stephenson and Winnebago counties, 

 where the nuggets are spoken of as much worn and rounded, 

 and Boone, Ogle and Lee counties,' by James Shaw, of the 

 Illinois survey. Woodford ' and La Salle counties, have 

 also yielded specimens of " float mineral," as noted by H. A. 

 Greene. In Will county, a specimen of considerable size 

 was found near Wilmington, probably in a lacustrine for- 

 mation, while many smaller ones have been discovered both 

 here and in Cook county." 



The dotted area on the map represents the area of the copper-bear- 

 ing series, essentially as determined by Prof. R. D. Irving.. The drift 

 copper is represented by dots, located as exactly as the data at hand will 

 permit. No attempt is made to show the relative sizes of the different 

 pieces. Where the statement has been made that " float copper " is fre- 

 quently found in a certain county, several dots have been placed within 

 the limits of such county. Where but a single find has been authorita- 

 tively reported from a given district, the fact is indicated by a single dot. 



^ Vol. I, Illinois Geological Report, p. 233. 



- Ibid., vol. VI, pp. 10 and 98. 



3 Ibid., vol. IV, p. 244. 



* Ibid., vol. IV, p. 65. 



5 Ibid., vol. IV, p. 77. 



« Ibid., Vol. V. 



Ubid., Vol. IV. 



»F. H. Bradley, ibid., vol. IV. 



