24S Remarks on Native Silver from Michigan. 



The blackish colour of some parts of this latter mineral, would, 

 at a first glance, lead us to attribute this colour to the presence 

 of hornblende ; but on a closer examination, it will be perceiv- 

 ed to be owing to a dark coloured steatite, which, in certain 

 parts of the rock, is well developed, soft, and easily cut. A 

 little calcspar is intermingled with the steatite. 



Locality. I am indebted to the politeness of Lieut. Lewis S. 

 Johnston, of the British Indian Department, at Maiden, (U. C.) 

 for the opportunity of adding this specimen to the mineralogi- 

 cal cabinet of the Lyceum. This gentleman, as he informed 

 me, obtained it from the south-eastern shores of Lake Huron, 

 near Point aux Barques, in Michigan Territory. That part 

 of Lake Huron was cursorily examined by me, in the year 

 1820, in the course of the expedition conducted by Gov. Cass, 

 through the upper lakes, &c. We considered it remarkable, 

 even in a region abounding in rolled rocks, for the great num- 

 ber and variety of granite, gneiss, hornblende, and trap bowl- 

 ders, scattered along the shores of the lake. The water here 

 is generally shallow, and dangerous to approach in vessels ; 

 these bowlder stones sometimes extending and presenting 

 themselves above water for a mile or more from land. But 

 we could not satisfy ourselves, by an examination necessarily 

 partial, that either of the primitive species mentioned, existed 

 there in any other condition than as rolled masses, or displace- 

 ments of rock strata, contiguous, perhaps, but not observed. 

 Dr. Bigsby has informed me, that he observed the gneiss, 

 in situ, on the north-western shores of this lake. The nearest 

 rock in place, and that which in fact constitutes the abraded 

 and caverned promontory of Point aux Barques, is gray 

 sandstone. 



