20 
trary that Zirconia is readily and completely soluble in Oxalic 
Acid. 
In Finkener’s revised edition of H. Rose’s work, the error 
contained in earlier editions is corrected. 
(8) Berlin found the Sp. Gr. of Zirconia from Catapleite 
=4.9, precisely the mean of the other two. 
(9) The manner in which Sorby has explained the last 
point is familar to all. 
Frederick Prime, Jr., read a paper 
ON THE METALLURGY OF ARGENTIFEROUS GALENAS, 
giving details of the several processes at present in use, with 
their various advantages and disadvantages. He entered 
into a detailed account of the methods put into practice in 
Freiberg, and showed how these could and would be used in 
the United States. 
Dr. J. S. Newberry read a paper on 
THE ANCIENT LAKES OF WESTERN AMERICA, THEIR 
DEPOSITS AND DRAINAGE. 
He first alluded to the wonderful collections of fossil plants 
and animals, brought by Dr. Hayden from the country bor- 
dering the upper Missouri, which are from deposits made in 
extensive fresh-water lakes which, at one time, occupied 
much of the region lying immediately east of the Rocky 
Mountains. The water of these lakes was first salt or brack- 
ish, as the remains of oysters and similar estuary forms show. 
By continental elevation the whole country west of the 
Mississippi, was raised out of the Cretaceous sea, and these 
estuaries became lakes inclosed by raised dry land. The 
knowledge of this country from the Mississippi to the Pacific 
Ocean, has been accumulated by various explorers besides 
himself, as Dr. Hayden, Mr. George Gibbs, Professors W. P. 
Blake and Thomas Antisell, and Prof. J. D. Whitney and 
the state Geological Survey of California, and Baron Richtofen, 
