46 Schoolcraft on the Copper of Lake Superior. 



ly carbonic acid and water. It is consequently anaong the 

 number of the ores of this metal that are most profitably 

 wrought in the large way. Should you entertain a wish to 

 place a portion of the ore transmitted in the hands of a chem- 

 ist for the purpose of analysis, I lake the liberty to suggest 

 that the envelope containing the small granulated masses, 

 would probably afford the fairest test. 



It may be pertinent to add to the foregoing remarks, that 

 I have succeeded in the course of the present season, in 

 procuring from lake Superior, a mass of native copper 

 weighinsi forty-two pounds, which is very pure and mallea- 

 ble, and contains? small points of native silver! This mass 

 is from the waters of the Ontonn'agon, but it is no part of 

 the great mass formerly described. 



HENRY R. SCHOOLCRAFT. 

 U. S. Indian Agent, resident at St. Mary's. 



Hon. John C. Calhoun Secretary of War. 



Localities of Minerals. 



Sulphate of Strontian. — Presque Isle, on the Maumee 

 I'iver, Wood County, Ohio. This locality is the site of 

 Wayne's celebrated victory over the confederated Indians 

 in 1794. The Maumee river here washes a rocky shore, 

 surmounted by a grove of oaks, with an extensive prairie 

 back of it. The crystals of Strontian are plentifully im- 

 bedded in the rocky bank of the river, which is a compact 

 limestone, similar, in its characters, to that which pervades 

 the shores of lake Erie. It is about 40 miles south of the 

 noted locality of this mineral upon "Strontian Island," and 

 indicates how extensively this substance is distributed 

 through that section of country. There is nothing peculiar 

 ift the forms of the crystals found at this place, or other 

 characters, unless it is a tendency in the colour of all the 

 specimens observed, to assume a full sky blue. Some of 

 these crystals contain other crystals of calcareous spar im- 

 bedded. I first visited this locality in July, 1821. I have 

 also in my posession a nodular mass of limestone from the 

 north shore of lake Huron, having impressions of the ma- 

 drepore upon its surface, which, on being broken upon one 

 end, disclosed radiated crystals of Sulphate of strontian, 

 in connexion with, and shooting into, limpid masses of folia- 



