We ascended that stream about thirty miles, to the great mass of that metal, whose existence has long been known. Common report has greatly magnified the quantity, although enough remains, even after a rigid examination, to render it a mineralogical curiosity. Instead of being a mass of pure copper, it is rather copper imbedded in a hard rock, and the weight does not probably exceed five tons, of which the rock is the much larger part. It was impossible to procure any specimens, for such was its hardness that our chisels broke like glass. I intend to send some Indians in the spring to procure the necessary specimens. As we understand the nature of the substance, we can now furnish them with such tools as will effect the object. I shall, on their return, send you such pieces as you may wish to retain for the Government, or to distribute as cabinet specimens to the various literary institutions of our country. Mr. Schoolcraft will make to you a detailed report upon this subject, in particular, and generally upon the various mineralogical and geological objects to which his inquiries were directed. Should he carry into effect the intention, which he now meditates, of publishing his journal of the tour, enriched with the history of the facts which have been collected, and with those scientific and practical reflections and observations, which few men are more competent to make, his work will rank among the most important accessions which have ever been made to our national literature. From the Ontonagon we proceeded to the Fond du Lac, passing the mouths of the Montreal, Mauvais, and Brulé Rivers, and entered the mouth of the St. Louis, or Fond du Lac River, which forms the most considerable water communication between Lake Superior and the Mississippi. The southern coast of the lake is sterile, cold, and unpromising. The timber is birch, pine, and trees of that description which characterize the nature of the country. The first part of the shore is moderately elevated, the next, hilly, and even mountainous, and the last a low, flat, sandy beach. Two of the most sublime natural objects in the United States, the Grand Sable and the pictured rocks, are to be found upon this coast. The former is an immense hill of sand, extending for some miles along the lake, of great elevation and precipitous ascent. The latter is an unbroken wall of rocks, rising perpendicularly from the lake to the height of 300 feet, assuming every grotesque and fanciful appearance, and presenting to the eye of the passenger a spectacle as tremendous as the imagination can conceive, or as reason itself can well sustain. The emotions excited by these objects are fresh in the recollection of us all; and they will undoubtedly be described, so that the public can appreciate their character and appearance. The indications of copper upon the western part of the coast, are numerous; and there is reason to suppose that silver, in small quantities, has been found.