2O THE CHICAGO ACADEMY OF SCIENCES. 



Mr. W. R. Hornbaker reports finding a pyritiferous boul- 

 der in drift which assayed yielded 5-100 ounces gold per ton 

 and silver 48-100 ounces. 



Silver. Ag. Regular. 



Small threads of native silver appear in some of the copper 

 specimens found in the drift. They have the physical charac- 

 teristics of silver, being without cleavage, being malleable and 

 ductile, having a hardness of 2.5 to 3, a gravity of 10.1, a whit- 

 ish color, and solubility in nitric acid. Ossian Guthrie reports 

 the finding of a silver specimen at the Sag but does not describe 

 it. (Page 5 in " Relics Turned Up in the Drainage Canal", 

 Journal Western Society of Engineers.) 



Copper. Cn. Regular. 



Many copper specimens have been found in the drift in 

 various parts of the Chicago area. Guthrie gives the following 

 list: 



1. Fragments found at Drainage Canal, now at Calhoun 

 School, I/?, pound. 



2. Thirteen pound piece found at Worth distorted in 

 stone crusher, PI. IV, fig. I. 



3. Eighteen pound piece found in the Drainage Canal. 



4. Fifty-five pound piece now at the National Museum, 

 Washington. 



5. Sixty-seven pound piece. 



6. Ninety-five pound piece, pressed and rolled till bent 

 over a pebble. 



7. One hundred twenty pound piece found at Dwight. 



8. One hundred sixty-eight pound piece, found near the 

 penitentiary at Joliet. 



Could these pieces have fallen off of freight cars, could 

 they have been placed where found by interested men or by 

 Indians, or do they properly belong among the minerals char- 

 acteristic of the region? Answer to these questions is found 

 in the localities in which they were found and in their 

 physical peculiarities. In the first place all have been found 

 in the drift, accompanied by igneous and metamorphic rock. 

 Some of them were a long distance from railroad or wagon 

 road and deeply buried. They were found by different people 

 in presence of witnesses in different localities. In the second 

 place, upon comparison with samples of pig copper their dis- 



