GEOLOGY. 303 



which the diamond was attached to its matrix. From these facts it appears 

 that the " Star of the South" has been only one of a group of diamonds simi- 

 lar to the groups of rock crystal, coal spar, or any other crystalline mineral 

 Compte Bendiis, vol. xl., p. 3. 



OX THE DISTRIBUTION OF IROX. 



Mr. J. D. "Whitney in a communication to the American Association, Provi- 

 dence, remarked that there were scattered over the earth deposits of iron of 

 peculiar character and extraordinary purity, and that the mode of their occur- 

 rence was also peculiar ; they belonged to certain sj-stems of rocks, and were 

 found only in those systems. The principal localities hi which this iron oc- 

 curred were Scandinavia, Northern New York, Superior and Missouri. In 

 Sweden there was a single bed 700 feet in width by four or five miles in 

 length. The deposits in northern New York were not so extensive, but the 

 Cleveland Iron Mountain in the Lake Superior country rose to the height of 

 1,039 feet above the lake, with a breadth of 1,000 feet, and was entirely com- 

 posed of iron ore. Along its summit were numerous knobs 50 to 100 feet in 

 height, which were perfectly pure. There were numerous other mountains in 

 Missouri which furnished equally pure ores. The ores thus found were almost 

 always of two kinds, specular and magnetic. The specular predominated in 

 Sweden, Superior and Missouri, while the magnetic prevailed in northern New 

 York. In Superior the iron beds lay between trap and talcose slate ; in Mis- 

 souri porphyry was near ; in New York it seemed to have been sedimentarily 

 deposited in lenticular masses, and afterwards subjected to metamorphic ac- 

 tion ; these all in azoic rocks. As the azoic periods were more violent in 

 their action than later periods, it was probable that what was thrown up 

 during those periods came from a deeper portion of the earth, and we might 

 hence infer that there were great deposits of pure iron deep down in the 

 earth. 



Professor Hall in reply to a question, stated, that ah 1 the rocks below the 

 paleozoic, which occurred in any considerable quantities hi this country, 

 were metamorphic from sedimentary rocks. Not only the great systems of 

 these rocks, but even subordinate portions of them had been deposited under 

 somewhat different circumstances physically and chemically. Although some 

 shells and sandstones in different formations might have considerable simi- 

 larity, still they presented differences, and these slight differences were 

 brought in metamorphism. He was satisfied that when our metamorphic 

 rocks came to be more thoroughly known, every group that had had any con- 

 siderable characteristic in its original formation would in its metamorphoric 

 state be found to present such peculiar minerals as to characteriz3 it as per- 

 fectly as the fossiliferous rocks are characterized by their fossils. 



> 



OX THE OCCURRENCE OF XATIYE IROX IX LIBERIA. 



During the year 1853, a specimen of malleable iron was sent from the 

 vicinity of Bexley, Bassa County, Liberia, to "William Coppinger, Esq., of 



