Trans. N. Y. Ac. Sci. 14 Oct. 29; 
The PRESIDENT then gave a description of the geological structure 
at Ontonagon, in the Keweenaw peninsula, of the Porcupine Moun- 
tains, the distribution of the Potsdam sandstone, and of the underlying 
rocks, the Copper series, which in the Eastern States are represented 
by the Taconic or Cambrian slates, and on the north side of Lake 
Superior by the Anemikee rocks of HUNT. 
Mr. C. VAN BRUNT referred toan ancient mining excavation along 
the south wall of a vein at Houghton. From this trench much copper 
had been extracted by the old miners, and charred remnants of wood 
and many stone tools were found at the bottom. 
The PRESIDENT remarked on the ancient works of the Lake Sei 
region, which were much more extensive, notwithstanding the imper- 
fect means and absence of machinery at the disposal of the prehistoric 
miners, than those of the whites, by whom these veins have been 
worked only since about the year 1847. The guide of the early ex- 
plorations of the latter has been, almost invariably, the ancient works, 
mounds, and excavations of their prehistoric predecessors. The 
old works were never deep. The tools employed were rude stone 
mauls, sometimes very heavy, which were attached to handles by 
withes around a groove at the middle, and were slung by several 
persons: others were much smaller, and were handled by a single 
person. He had seen but one copper mining-tool which had been 
fashioned and used by them. The PRESIDENT also described the 
glacial phenomena of the Ontonagon region—the polish and striation 
of outcrops, abundant boulders, etc., and then referred to some of the 
most interesting papers recently read at the Minneapolis meeting of 
the American Association for the Advancement of Science. The 
papers of Mr. WM. MCADAMS were particularly important, describ- 
ing his discoveries of the bones of some large, new fossil fishes in the 
Carboniferous limestone at Alton, Ill, the skull of the giant beaver 
(Castoroides), etc., in the Quaternary, and a large number of bones 
and teeth found at the bottom of the Loess or Bluff Formation ; these 
last remains are likely to throw great light on the true character and 
history of the Loess. 
October 29, 1883. 
SECTION OF CHEMISTRY. 
The President, Dr. J. S. NEwsBerry, in the Chair. 
Thirteen persons present. 
Prof. D. S. Martin exhibited a.specimen of the ashes thrown 
out at the remarkable eruption of the volcano Krakatoa, in Java, 
during last August. 
