Scientific Intelligence. — Geology. 375 



16. Arctic Minerals. — Before we take leave of arctic subjects, 

 says Sir Roderick Murchison, let me remind you that, judging from a 

 memoir communicated by M. Lundt of Denmark, and lately read to 

 our society by Sir Walter Trevelyan, on the mineral produce of the 

 southern parts of Greenland, we have every reason to think that 

 valuable ores of copper may be found to extend far to the north of 

 the tracts around Disco, where the minerals in question were ob- 

 served. Judging from the few rocks submitted to my inspection by 

 Captain Inglefield, and which were collected in the more northern 

 parallel of 77°, I should infer, from their crystalline character, that 

 a very large portion of this region may prove to be metalliferous, 

 and that industry may there be rewarded with spoils of the land, as 

 well as by catching the whales and seals of the sea. — (Sir Roderiek 

 Murchison s Address to the Royal Geographical Society r , vol. xxiii., 

 p. lxxxiii.) 



GEOLOGY. 



1 7. The Lower Silurian Rocks of the United States. — One of the 

 chief geological facts ascertained in reference to the origin of life in the 

 crust of the globe, is the discovery of certain fossil animals (trilobites) 

 in strata lower than any in which they had been found in America, 

 but which are precisely on the same horizon as the lowest fossil- 

 bearing Silurian rocks of Britain, Scandinavia, Russia, and Bohemia, 

 where trilobites also occur in the same relative position. Excuse 

 me, then, if I say that I felt no small pride when I saw that M. 

 Owen had mapped all these rocks as lower Silurian, and as agreeing 

 with those which, under that name, I have defined to be the lowest 

 fossiliferous rocks of Europe. These and other palseozoic rocks, the 

 equivalents of our Devonian, are surmounted by carboniferous masses 

 of such extent, that one of them may be mentioned as a coal-field 

 larger than England. — (Sir Roderick Murchison s Address to the 

 Royal Geographical Society?) 



18. Nature of the Coral-Reefs between the coasts of Florida and 

 Mexico. — I must, indeed, specially allude to an admirable illustra- 

 tion of the true nature of the coral-reefs between the coasts of 

 Florida and Mexico, the " Keys" of the seamen. In a separate 

 report on the topography of that tract, in relation to the former, 

 present, and probable future condition of such reefs, Professor 

 Agassiz has successfully shewn how all such surveys ought to be 

 made in conjunction with naturalists. For, quite independent of the 

 important additions to natural history knowledge which are obtained, 

 statesmen as well as hydrographers thus ascertain the causes of in- 

 crease or decrease of coral reefs, and learn that whilst no human 

 power can arrest the growth of such reefs, there are channels 

 amidst them which will remain deep in long periods of time, and 

 the outlines of which, when well defined by lighthouses, may be the 

 salvation of much life and property. In other words, the fixed and 

 stable points, of land and the channels which are dangerous, are 



