1822.] Native Copper of Lake Superior, S^c.** 59 



The expenditure of considerable sums in unsuccessful trials* 

 and consequent loss and disappointment, have often been the 

 result of acting upon speculations similar to those quoted by 

 Mr. Schoolcraft, which, though certainly plausible, are not borne 

 out by experience, and which, therefore, it is desirable should be 

 known, are founded only on a popular error. 



It is not uncommon to see specimens of ore of great richness 

 exhibited, and to hear it inferred that they are a certain prog- 

 nostic of valuable mines, whereas experienced miners know 

 that they are to be considered merely as rarities, that they occur 

 frequently in irregular deposits, and seldom in any large quan- 

 tity. The regular veins from which alone a miner would expect 

 much, are generally enriched in a different manner ; and when 

 ore occurs in large masses so as to be worth working, those 

 masses are usually composed of those varieties which are not 

 extraordinarily productive of metal.' 



Native copper and very rich copper ores do occur indeed in 

 veins, and have been often found in some of our best mines ; 

 but they are of themselves not relied on as promising indica- 

 cations, unless accompanied by other favourable symptoms, and 

 must be considered as rare productions, rather than as forming 

 any notable part of the produce of mines, 



In judging of the probabihty of any country being productive 

 of copper, a miner would attend to the appearance or discovery 

 of regular veins, — to their extent, — to the rocks in which they 

 occur, — the substances which they contain, — and to many other 

 things which he would deem more important than any casual 

 specimens of the metal or its ores, and particularly the richer 

 varieties. 



He would require at least a combination of some of those 

 indications which experience has shewn to be favourable in 

 order to pronounce that expensive trials were justifiable, or that 

 success was probable; and in forming his judgment, such evi- 

 dence as is here produced would have but little weight. 



With regard to the probability of copper being found in the 

 country described by Mr. Schoolcraft, near Lake Superior, so as 

 to become an object of research, it appears to me that from 

 his report, there is very little to encourage such an expectation. 

 Scattered fragments of native copper are found inclosed in 

 masses of rock, not even in situ, — their original situation un- 

 certain, — the rock itself not commonly productive of copper, — 

 the surrounding country alluvial, or composed of red sand- 

 stone, — no indication of veins, — and no appearance of substances 

 as are most frequently found accompanying the ores. 



The fact is a very curious one, and if, as Mr. Schoolcraft spe- 

 culates, these masses may have been ejected from volcanoes in 

 the Porcupine Mountains, it would be more desirable to exa- 

 mine those mountains than the district in which they now ap- 

 pear to be placed by some extraordinary chance. 



John Taylor. 



