Scientific Intelligence. — Geology. 189 



Lake of the Woods, 1,040 



Dog Lake, 1,000 



Source of the Miami, «^........ 964 



Source of the Sciota, ...»'...........'».';.V.'^!!. 919 



Sources of the St Peter and Red Rivers, 830 



Mouth of the Platte, Missouri, 680 



Mouth of the St Peter, Mississippi, 630 



Lake Winnepec, 595 



Lake Superior, . 571 



Lakes Hurori and Michigan, 571 



Ohio, near Wheeling, Virginia, 565 



Lake Erie, 665 



Ohio, at Cincinnati, 414 



. Point Levi, opposite Quebec, 310 



Mouth of the Ohio, 300 



Lake Ontario, ....-d>.JA*.l^.^..ii:.... 231 



Featherstonehaugh's American Jtmmal tf Geology. 



MINERALOGY. 



7. On the Gold^ Silver, and Platina of Russia. — The an- 

 nual produce of silver in the Russias, is estimated at about 1000 

 pouds, of forty pounds each ; but what, after all, is this 1000 

 pouds, or 40,000 pounds, to the produce of the Valenciana mine 

 in Mexico, which for many long years produced its millions of 

 dollars annually .? " Young Demidoff had not yet returned from 

 Italy ; from his relation and agent DanilofF, I met with every 

 attention. His cabinet contained many beautiful specimens of 

 platina, most of which were designed as presents to the crowned 

 heads of Europe. Although some single masses of platina 

 weighed seven or eight pounds, none could be compared to 

 those in the cabinet of the mining corps, one of which weighed 

 about 27 pounds. My own specimens, which were presented 

 to me by Zobolefsky, ahhough weighing 800 grains each, and 

 of which I had been not a little proud, dwindled away in the 

 view of the great varieties lying in profusion in DemidofPs ca- 

 binet. Owner of the most celebrated platina deposits, and gold- 

 washings, he had had many opportunities, in the course of a 

 few years, of selecting and putting aside not only large massive 

 lumps of gold and platina, but what was yet more interesting, 

 a great variety of most beautiful and perfect crystals of gold. 

 The mass of platina before alluded to, as weighing 27 pounds, 

 jwas found completely isolated, and at nearly 60 versts from the 



