E. MINERALOGY AND GEOLOGY. 12 l 



without an outlet, as are also those of Lake Araqua, in Ven- 

 ezuela, and the lakes near Damascus, into which the Abana 

 andPharpar respectively discharge. 12 A, Jan. 11,1872, 203. 



PHOSPHATE BEDS ON THE DNIESTER. 



The immense deposits of mineral phosphates in South Car- 

 olina bid fair to be matched by those lately discovered on 

 the banks of the Dniester, in Eastern Europe. From a re- 

 port of an investigation by Schwackhufer, ordered by the 

 Austrian government, we learn that these phosphatic concre- 

 tions differ from those hitherto observed in bein^ almost en- 

 tirely globular, with concentric radiated joints in their inte- 

 rior, and varying in diameter from half an inch to eight inch- 

 es. When powdered, and heated in the dark, a bluish phos- 

 phorescent light is observed. The region in which the phos- 

 phorite balls occur is characterized by the existence of Silu- 

 rian and cretaceous strata, all intermediate formations being 

 wanting. The silurian strata are principally represented by 

 limestone and clay slate, and the latter is either coarsely 

 granulated and compact, or in smooth, lustrous sheets. It is 

 in the latter alone that the phosphatic balls occur, and, in- 

 deed, only where this slate is immediately covered by the 

 chalk marl. From these considerations, it is inferred that the 

 balls consisted originally of carbonate of lime, which have 

 been transformed into phosphorite by the infiltration of phos- 

 phatic salts. The original material of these chalk concretions 

 was doubtless supplied by the chalk marl overlying the slate 

 in a manner familiar to geologists, and it may fairly be pre- 

 sumed that the phosphoric acid of the mineral is simply the 

 product of leaching out of the phosphatic slate above referred 

 to, since all the other constituents of the slate besides phos- 

 phoric acid are found in this mass. Herr Schwackhufer imi- 

 tated the mode of forming these balls by taking boys' mar- 

 bles and keeping them for several days in a solution of phos- 

 phate of soda or of iron, and observed the transformation into 

 phosphate of lime. An acid phosphate of lime is first pro- 

 duced, which is subsequently changed into the insoluble salt. 

 In nature this process must have been a long time in prog- 

 ress, but the result was sure to be attained ultimately. As 

 to quality, this phosphate promises to be of very decided val- 

 ue, showing a positive superiority over that of the Sombrero 



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