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Mineralogy

Magnetic Oxite of Iron. A boulder consisting almost entirely of this [rock] ore has been found near Milwaukee; it had been cracked and broken by the action of the weather. The black sand so abundant on the shores of all the Great Lakes is [nothing but] the magnetic iron ore reduced to powder or sand by the action of the waves. Near Sheboygan, and at various other points it exists in large quantities; and the people of Milwaukee supply themselves with this article from the Lake shore in the vicinity of the city. Near the mouth of the Bois Brule river on Lake Superior we are informed by Mr. Schoolcraft, that there is a layer a foot in thickness extending along the shore of the Lake some distance. This sand is thrown upon the beach by the force of the waves especially during heavy storms of wind, and its great specific gravity prevents its being carried back by the diminished force of the returning waves.

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