CERTAIN ABORIGINAL REMAINS OF THE ALABAMA RIVER. 329 



This native copper is present in great quantities near Lake Superior, where 

 aboriginal mines have been discovered; nuggets are found in the "drift" and 

 native copper, to a certain extent, has been found in various States and in Cuba. 



In Europe the supply of copper is not obtained from native copper but from 

 ores, almost invariably sulphide ores, which are rich in impurities and contain 

 quantities of arsenic, etc., which even now are hard to eliminate and which, in 

 earlier times, were more than the rude smelting processes of those days could suc- 

 cessfully cope with. It is stated that earlier German coins have, in late years, been 

 resmelted with profit to obtain the silver contained in them. 



In Europe, farthermore, it was the custom to introduce lead during treatment 

 of the copper ores. 



Now, analyses of copper found in aboriginal mounds in which no objects of 

 European provenance are present, show the copper to be of the highest purity and 

 always free from lead. 



Therefore, we know that the aborigines of this country made use of native 

 copper. They could not have obtained the metal from the whites, as it is purer 

 than could be smelted to-day from the sulphide ores of Europe and is far purer than 

 was produced by the comparatively rude processes of the 16th, 17th and 18th 

 centuries. 



The reader may see from the foregoing that there should be little difficulty in 

 determining chemically the provenance of copper, provided a careful analysis is made. 1 



In the Charlotte Thompson Mound, which, from top to bottom, contained arti- 

 facts of European origin in close, association with objects of aboriginal make, a 

 study of the copper is of particular interest. 



One of the breast-pieces from the mound had an irregular appearance, showing 

 uneven thickness and marked lamination, the overlapping of parts of the copper 

 upon other parts, which we often see in aboriginal work, being markedly noticeable 

 and particularly so when a section of the piece, cut out for analysis, was examined 

 along the edge. This piece was marked "A" and submitted to H. F. Keller, Ph.D., 

 Professor of Chemistry of the Boys' High School, Philadelphia, and long an expert 

 in copper in the " Lake " regions of Michigan. The analysis of the plate marked 

 "A" is subjoined. 



" This metal is of extraordinary purity. Minute quantities of iron and silver 

 are the only impurities distributed throughout its entire mass. 



" Quantitative determinations yielded : 



Silver . . 0.0022 per cent. 



Iron 0.0272 " " 



'•In one part of the plate a very small proportion (0.0016 per cent.) of lead 

 was also found, but this must be regarded as due to local contamination from an 

 external source, for other parts of the same plate are absolutely free from lead. 

 Other metals, such as bismuth, antimony, arsenic, nickel, etc., are also entirely absent. 



1 The analysis should be made with the utmost care, bearing in mind that most of the sulphuric 

 acid to be had in this country contains lead. Analyses made for us are duplicated in blank to guaran- 

 tee absence of foreign matter from the chemicals employed. 



42 JOUEN. A. N. S. PHILA, VOL. XL 



