ICINEBALOGr. 239 



and also — axis of rotation the normal to the basis. The macrodiagonal 

 law holds also in anorthite. Concludes, from the character of twin- 

 striation on ooPx , that certain crystals from Bamle, in Norway, are 

 oligoclase and not anorthite. Finds typical labradorite twinned ac- 

 cording to the macrodiagonal law. Shows the value of the direction of 

 twin-strisB as a means of diagnosing the triclinic felspars. F. W. R. 



Rath, G. vom. [Crystallization of Leucite.] N. Jahrb. Heft iii. 

 pp. 281-285. 



Reply to objections of Dr. Hirschwald against the view that leucite 

 crystallizes in the quadratic system. Dwells on his opponent's miscon- 

 ception of poly symmetry ; and holds that as poly symmetry is only a 

 special case of dimorphism, it follows that if leucite is polysymmetric it 

 must be dimorphous, and that Hirschwald is wrong in recognizing only 

 one species — the regular. F. W. R. 



[Mineralogical Notes.] N. Jahrb, Heft iv. pp. 386-405 ; 



plate. 



Occupied chiefly with crystallographic details referring to — (1) small 

 cr}^stals(R . oR) of iron-glance seated on largo octahedra of magno-ferrite, 

 from Vesuvius ; (2) parallel growth of small crystals of biotite on older 

 and larger crystals of augite, from the eruption of Vesuvius of April 

 1872, and of crystals of hornblende and of augite similarly placed ; (3) 

 twin-crystals of turnerite from Tavetsch and the Binnenthal ; (4) 

 crystals of scorodite from Dernbach, Nassau ; (5) paramorphs of rutile 

 after Arkansite from Magnet Cove. Also discusses the priority of 

 description of the regular growth of calcite and quartz at Schneeberg, 

 and carries on the discussion as to the crystallization of leucite. F. W. R. 



Raid, W. C. Mineral Phosphates and Superphosphate of Lime. 

 Chem. News^ vol. xxxiv. no. 871, pp. 48-50 ; no. 872, pp. 55, 56. 



1. Contains analyses of Cambridge, Suffolk, and Boulogne nodules; 

 of S. Carolina and Bordeaux phosphates. 2. Contains analyses of 

 phosphate of lime from Nassau, Spain, Norway, and Canada ; and of 

 guano from Sombrero and Navassa in the Caribbean Sea. F. W. R. 



Reusch, E. Note zur Laspeyres's Abhandlung : Krystallographische 

 Bemerkungen zum Gyps. [Laspeyres's Crystallographic Remarks 

 on Gypsum.] Min, Mitth. Heft i. pp. 67, 68. 



Roscoe, Prof. [H. E.] Recent Discoveries about Vanadium. Proc. 



R. last. vol. viii. pp. 221-230. 

 Two new vanadium minerals are mentioned, viz. Mottramite 



(CuPb)3VA + 2(CuPb)(0H),; 

 and Roscoelite 



4ArVO,4-K,Si,0^ + H,0; 



the latter is a greenish talc-like substance, occurring in cavities in 

 schistose porphyry. R. B. N. 



