300 APPENDIX. 



which will be forwarded to the "War Department. This specimen 

 is partially enveloped with a crust of green carbonate of copper. 

 Small fragments of quartz and sand adhere to the under side, 

 upon which it would appear to have fallen in a liquid state. 

 Several smaller pieces of this metal were procured during our 

 excursion up the Ontonagon, or along the shores of the lake east 

 of this stream. 



It may be added that discoveries of masses of native copper, 

 like those of gold and other metals, are generally considered 

 indicative of the existence of mines in the neighborhood. The 

 practical miner regards them as signs which point to larger bodies 

 of the same metals, in the earth, and he is often determined by 

 discoveries of this nature in the choice of the spot for commencing 

 his labors. The predictions drawn from such evidence are more 

 sanguine in proportion to the extent of the discovery. They are 

 not, however, unerring indications, and appear liable to many 

 exceptions. Metallic masses are sometimes found at great dis- 

 tances from their original repositories ; and the latter, on the con- 

 trary, sometimes occur in the earth, or imbedded in rock strata, 

 where there have been no great external discoveries. 



From all the facts, which I have been able to collect on Lake 

 Superior, and after a full deliberation upon them since my return, 

 I have drawn the following conclusions: — 



1. That the diluvial soil along the banks of the Ontonagon 

 Eiver, extending to its source, and embracing the contiguous re- 

 gion, which gives origin to the Monomonee Eiver of Green Bay, 

 and to the Wisconsin, Chippewa, and St. Croix Rivers of the Mis- 

 sissippi, contains very frequent, and several extraordinary masses 

 of native, or metallic copper. But that no body of this metal, 

 which is sufficiently extensive to become the object of profitable 

 mining operations, has yet been found at any particular place. 

 This conclusion is supported by the facts adduced, and, so far as 

 theoretical aids can be relied upon, by an application of those 

 facts to the theories of mining. A further extent of country might 

 have been embraced, along the shores of Lake Superior, but the 

 same remark appears applicable to it. 



2. That a more intimate knowledge of the mineralogical re- 

 sources of the country, may be expected to result in the disco- 

 very of valuable ores of copper, in the working of which occa- 



