398 Scientific Intelligence — Geology. 



6. 'Level of the Caspian and Dead Seas. — The Caspian Sea, ac- 

 cording to A. Erman, in 1836, is 84 metres (266 feet) below the level 

 of the Black Sea. The Scientific Commission from the Russian Go- 

 vernment in 1837, found it 101-2 feet (English.) M. H. de Hell 

 has concluded from a barometric levelling, that the difference of level 

 between the Caspian and Sea of Azof, is only 18-30-4 metres. From 

 the geodesic results of Sabler and Sowitsch, M. Hell deduced 33*7 

 metres, and afterwai-ds 27, as the difference of level. From the 

 same observations, Humboldt, obtained 81*4 feet (English.) 



M. Cailler (1839) deduced from the observations of Bcrtou (1837 

 and 1839), Moore and Beet (1837), and Schubert (1837), as a 

 mean, that the Dead Sea is depressed 185 metres below the Medi- 

 terranean. Bertou placed it at 41 9-6 metres. David Wilkie (in 1842) 

 found the depression 365 metres ; Lymonds, 427 metres ; Ru- 

 segger (1841), 434 metres. Delcros (1843) derives from all the ob- 

 sei'vations, that 426-3 metres is the amount of depression. Moore 

 and Beck sounded 300 fathoms in the Dead Sea without finding 

 bottom. — (D'Archiac, Hist. Geol.) 



7. Common Salt. — The amount of common salt in all the oceans, 

 is estimated by Schafhfiutl at 3,051,342 cubic geographical miles. 

 This would be about five times more than the mass of the Alps, 

 and only one-third less than that of the Himalaya. The sulphate 

 of soda equals 633,644-36 cubic miles, or is equal to the mass of 

 the Aljis. The chloride of magnesium, 441,811-80 cubic miles ; the 

 lime salts 109,339-44 cubic miles. The above supposes the mean 

 depth to be but 300 metres, as estimated by Humboldt. Admit- 

 ting, with Laplace, that the mean depth is 1000 metres, which is 

 more j^robable, the mass of marine salt will be more than double the 

 mass of the Himalaya. — (^American Journal of Science and Arts, 

 Second Series, No. 16, July 1848, p. 148.) 



8. Talus Slopes. — In the chains of the Vosges and Jura, Leblanc 

 found no talus exceeding an inclination of 35°. This slope, he ob- 

 serves, is most rigorously the inclination of the diagonal of a cube. 

 The density of the material has no effect on the slope, as the ava- 

 lanches of snow and fall of rocks take the same slope. Some rough 

 rocks, as trachyte and sandstone debris, may form a declivity of 37° 

 to 39°. A talus of 42° to 45°, is not one of stable equilibrium. — 

 (^American Journal of Science and Arts, Second Series, No. 16, 

 July 1848, p. 133.) 



9. On the Remains of Marine Shells of Existing Species found 

 interspersed in deep portions of the Hills of Drift and Boulders in 

 the Heights of Brooklyn, on Long Island, near New York City. 

 By W. C. Redjield. — These remains had long since attracted the 

 attention of Dr Mitchell, and other naturalists of the vicinity ; but 

 the true character of the formation and the peculiar positions in 

 which the shells were found, were not distinctly known to geologists. 



It fortunately happened that M. Desor and Count Portals, while 



