J. D. Dana— Origin of the Rocks of the Cortlandt Series. 117 
since these are the commonest of anhydrous sodium sili- 
cates. Science looks to the ocean for the boric acid of some 
minerals and the chlorine and iodine of certain silver ores and 
some voleanic products; and hence referring to it as a source of 
the more stable bases with which these were combined is not 
unreasonable. 
albite may have ‘ 
Messrs. F. Fouqué and Michel Lévy have recently made* 
quired proportions, and keeping it in prolonged fusion. ey 
have thus proved that the sodium of a sodium carbonate 
will, at a high temperature, enter into combination and make 
feldspars. The sodium of sodium chloride (common salt) 
of pro 
saliferous sedimentary stratum has therefore been put beyond 
question by actual experiment. Metamorphic heat would be 
as effectual; and, with the aid of moisture, probably at a lower 
temperature than that employed by Fouqué. 
schist contains, along a certain horizon, interrupted beds or 
lenticular masses of limestone—parts of which are more or less 
changed to serpentine and verd-antique marble; and below the 
limestone horizon, the schist, for a considerable thickness, con- 
tains irregular masses of labradioryte (labradorite-dioryte), the 
slaty-beds of the schist changing for short distances to labra- 
* Comptes Rendus, vol. Ixxxvii, pp."700 and 779, November, 1878. 
