MUSEUM OF COMPARATIVE ZOOLOGY, 11 



the Copper Mines of Lake Superior, and Observations on the Geology 

 of the Lake Basins and the Summit of the Mississippi ; together with 

 all the Official Reports and Scientific Papers of both Expeditions." As 

 giving us an insight into the early knowledge of the geology of the 

 southern shore of Lake Superior, this work naturally should be of great 

 value, especially as it purports to contain the original scientific reports. 

 In the Preface we learn that he brings the subject down to the date 

 of publication in some respects, and by comparing the work with the 

 original, published in 1821, we find that he gives discoveries as if made 

 by himself in 1820 which were not made until at least nearly twenty-five 

 years later. This insertion in the body of the text may perhaps be par- 

 doned, in the light of the Preface ; but when it comes to publishing offi- 

 cial documents with their original date and official signature, but with 

 a " tinkered " body, we object. We cannot therefore credit Mr. School- 

 craft with the discovery of the iron oi'e of the Marquette district in 

 1820, although any one reading this work would suppose that he dis- 

 covered it. It represents to us simply what he wished, in 1854, others 

 should think he had known and written in 1820. This also applies in 

 part to his reports on the Copper district, and we shall not mtution the 

 book further. 



In 1854 was also published a description of this and the Copper region 

 by Fr. C. L. Koch.* The trap and granite were regarded as eruptive, 

 and it was thought that the quartz rock (quartzite) may probably be so. 

 The schists are su})posed to have been metamorphosed through the 

 agency of igneous masses. The iron rocks he would consider as 

 upheaved from gi-eat depths, or else to have suffered great metamor- 

 phism by the influence of igneous masses. That they (the iron I'ocks) 

 may be simply the quartz rock impregnated with oxide of iron is thought 

 probable. 



In 1855 and 1856 two papers on this and the Copper district were 

 published by Prof. L. E. Ptivot.t As we understand his work, it would 

 seem that he regarded all the rocks from Sault St. Marie to the Onto- 

 nagon Piiver as of sedimentary origin, and of the same geological age, 

 whose differences were entirely owing to peculiar metamorphism, or its 

 absence, as the case might be. The sandstones were in general, in the 

 Marquette district, of prior deposition to the other rocks in the places 

 in which they ai'e now to be found. The traps and their associated 

 schists, which originally formed the base of the sandstone, had been 



* Stuilien des Gott. Vereins Bergni. Freunde, YI. 1-248. 

 t Annales des Mines, (5,) YIL 173-328, X. 365-474. 



