246 MINERALOGY. 



Kengott, Dr. A. Ueber die Krystallgestalten des Quarzes und die 

 trapezoedrische Tetartoedrie des hexagonalen Systems. [Crystal- 

 lization of Quartz, and Trapezohedral Tetartohedrism in the Hexa- 

 gonal System.] iV. Jahrh. Heft i. pp. 27-35 ; 3 woodcuts. 

 Maintains that the prism which is regarded as the normal prism ooP 

 in quartz is really the diagonal form ooP2, and that the pyramid P 

 should also be regarded as the diagonal pyramid P2. The trigonal 

 pyramids, trigonal prisms, ditrigonal prisms, and trigonal trapezohedra 

 all require change of sign ; and the writer holds that the change is 

 absolutely needed, since the ordinary conception leads to forms which 

 do not satisfy the geometrical characters of the hexagonal system, since 

 they require an unequal division of the secondary axes. P. W. E,. 



[Native Silver from Dauphine.] N. Jahrh. Heft i. pp. '5, 455. 



Note on Prof. Church's analyses [see Geological Pecoed for 1874, 

 p. 226]. Suggests that 26-15 p. c. of mercury is a misprint for 16*15 

 p. c, and calculates that one specimen contains 68*47 p. c. of AggHg, 

 whilst the other contains 77*76 of this compound, associated in both 

 cases with Ag.Sb. P.W. K. 



[Triplite from the Argentine Pepublic] N. Jahrh. Heft ii. 



pp. 171, 172. 



Discusses Siewert's analyses of Stelzner's Triplite from the Sierra 

 of Cordoba, and deduces for the paler variety the formula PF* 

 ■f 2(3PO . P'O^), and for the darker variety RP'-H3P0 . P'O^ 



P. W. R. 

 [Twin-crystals of Celestine.] N. Jahrh. Heft iii. pp. 293, 294. 



Announces the discovery of twin-crystals of celestine among Sicilian 

 specimens in the Polytechnic at Ziirich. Crystals are twinned parallel 

 to the pinacoid go Poo . P. W. R. 



Kern, Sergius. Analysis of Graphite from Siberia. Chem. News^ 



vol. xxxii. p. 229. 

 Analyses of 2 samples of graphite from the Stepanovsky mine. 



Kitten, J. On Silicious Substances found in Portland Stone. (Nor- 

 wich Geol. Soc.) Norwich Mercury., March 13, p. 3 ; and Science 

 Gossijj, vol. xi. pp. 112, 113. 

 Microscopic examination showed no trace of organic remains, so 

 common in flints. 



Klein, Dr. Carl. Mineralogische Mittheilungen No. V. JST. Jahrh. 

 Heft iv. pp. 337-370. 



Describes types of crystals of Anatase from the Binnenthal in 

 Switzerland : — 1. Type of acute pyramid, from predominance of P ; 

 2. Of obtuse pyramid from |P ; 3. Prismatic type from ocPoo ; 4. 

 Pyramidal type, from f P. Most of the crystals of anatase from this 

 locality have been mistaken for wiserin (xenotime). Describes a small 

 lioney-yeUow crystal from the Binnenthal, exhibiting combination of 

 P . ooP . 3P3, which he regards as true xenotime. F. W. R. 



