ANNIVERSARY ADDRESS OF THE PRESIDENT. xHx 



then stretching away into Minnesota and the immense expanse of 

 the far North-west. 



Although the first settlers took up their abode in this remote region 

 as earl J' as 1821, the mineral treasures cropping up to the surface 

 of the ground began to be worked only in 1827, when the name 

 Galena (from the well-known ore of lead) was given to the town, 

 which soon became the emporium of the lead-trade of the Upper 

 Mississippi. By the years 1840 to 1845 it had increased so largely, 

 representing at the maximum a production of about 25,000 tons a 

 year, as to exercise a powerful influence on the metal-markets of the 

 world. The description of the localities now laid before us offers 

 some explanation of the rapid exhaustion of deposits which used in 

 vague language to be termed mountains of lead. 



The veins or " crevices," as they are termed, thus confined to the 

 Galena limestone are found in great numbers, but never continuous 

 for more than a few hundred feet in length, scattered in patches 

 over a wide extent of territory, the productive ones ranging in an 

 east and west direction, and others of less value, but sometimes ore- 

 bearing, crossing that direction nearly at right-angles. Their appear- 

 ance in fact induces Prof. Whitney to infer, with much probability, 

 that the origin is due to the same causes that have produced ''joints " 

 in almost " every variety of rock occurring in large homogeneous 

 masses, and especially where a decided crystalline structure exists 

 in them." But the workings are rarely more than 80 or 100 feet 

 deep (in one or two instances, near Dubuque, nearly 180 feet), and 

 it seems that no trace of the metallic contents can be found below 

 the beds of the " Blue limestone," nor upwards in the '• Niagara sys- 

 tem." It is argued hence, with some boldness, that, the metal lead 

 having been held in solution in the oceanic waters from which the 

 rocks of the north-west were thrown down, the metalliferous combi- 

 nations were decomposed by the organic matter of these limestone- 

 beds, among which the ores are now found to occur ; and thus it 

 would seem to be inferred that the " crevices " were formed, and 

 were partly filled with the galena and its accompaniments of zinc- 

 blende, and fluor-spar, before the formation was covered up by the 

 deposition of the shales of the Niagara group. In curious juxta- 

 position with the metallic minerals which have contributed so much 

 to the peopling and investigation of the country, are found bones and 

 teeth of both extinct and living species of land animals, confusedly 

 mingled in the vein-fissures down to depths of 50 or 60 feet. The 

 most abundant are remains of Mastodon, which, from the quantities 

 found in difl'erent veins extending through the whole district, seem 

 to show that the species must have flourished in vast numbers and 

 through a long period of time. In one crevice, near Dubuque, Prof, 

 Whitney obtained, with bones and teeth of the Megalonyx, teeth of 

 a Peccary, pronounced by Wyman to be those of a species now living. 

 These curious facts remind us of the remarkable discovery made by 

 Mr. Moore, of Liassic and Oolitic fossils in the lead-bearing veins of the 

 Mountain-limestone of the Mendip hills, with the difierence that in 

 the latter case there is no doubt that the region of the fissures was 



