. 
Chemistry and Physics, 247 
Exaggerated ideas have been formed of the known mineral 
wealth of Alaska. 
y, be- 
ing nothing more than lignite pratt: that found Be the 
Arctic coast), and is of the most recent geological age. The 
coal on Ounga island is exposed in a bluff rising two hundred 
’ feet high fan the sea. Our own discoveries may lead to some- 
thing better. 
Magnetic iron ore is reported, but is not known certainly to 
exist in any large deposits. Lead ore, galena, is also reported 
ve been found at various places. 
Native copper is found on the Copper river, but the hostile 
esata’ of the Indians in 1 that locality has oa its ex~ _ 
plorat 
lary 
and bay of rsen at Serfierra ere pin of Al 
 Maetidée bones and teeth are found at Escholtz bay, Kotze- 
bue sound, and on the Pribulow islands. 
the interior topography of the country little is known; 
recent explorations made by Mr. Dall, who has explored the 
Youkon river extensively, will undoubtedly give us more au~- 
thentic and reliable information in regard to that than any 
heretofore avail able. 
San Franeiseo, January, 1868. 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PHYSICS. 
1. On the specific magnetism of iron; by Prrvy Earte Cuase.* 
—In my communication on the numerical relations of gravity and. 
magnetism (Trans. A. P.S., vol. xiii, p. 126), after adducing various 
evidences ¢ of a —— that had been long suspec endeay- 
ored to obtain ximate valuations for the constant factor, K, 
which was intro oad} in the comparison of the tidal forces with the: 
foree of equilibrium. These approximations led me to “suggest. 
* veil ios Proocedlagije tha American Philosophical Society, Nov. 15, 1867. 
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