MINERALOGY. 245 



T[8clien]iak ?]. Biotitzwillinge von Vesuvius. [Biotite-twins from 

 Vesuvius. Min. Mitth. Heft iii. p. 187. 



Differs from Vom Rath as to certain twin-crystals. Holds that all 

 Vesuvian biotite is monoclinic, not rhombohedral. Twins are consti- 

 tuted with twin-face 331. F. W. R. 



Typke, P. G. W. On a new Nickel Mineral from New Caledonia. 

 Chem. News, vol. xxxiv. pp. 193, 194. 



This nickel-ore is not homogeneous. The separation and analysis of 

 the more important constituent, an apple-green mineral, lead to the 

 conclusion that it is a hydrated nickel disilicate of the formula 

 SijOgNiHg. The author points out wherein this differs from other 

 analyses, and concludes that the mineral probably results from the 

 action of hydrated or soluble silicic acid upon some nickel compound, 

 producing products of variable composition. F. W. R. 



Ulrich, G. H. P. Selwynite, Noumeite, Garnierite. Amer. Journ. 

 ser. 3, vol. xi. p. 235. (Note dated Nov. 3, 1875.) 



Urba, Dr. K. Krj-staUographische Tafeln. iii Aufl. [Crystallo- 



graphic Plates.] Ed. 3. 8vo. Prague. 

 18 plates of drawings of crystals, mostly with Naumaun's symbols, 

 some figures with Dana's ; no letterpress. 



Uzielli, G. Sopra lo zircone della costa tirrena. [Tuscan Zircon.] 



Atti B. Ac. Line. Pp. 18. 

 On zircon from the Tyrrhenian coast. 



. Sopra la baritina e il ferro oligisto di Calafuria ; e sulla 



pirrotina deUa miniera del Bottino. [Barytes and Specular Iron of 

 Calafuria, and Pyrrhotine of the Bottino Mine.] Atti R. Ac. Line. 

 Pp. 8. 



W[atts ?], H. M. Blowpipe-analysis of the new mineral Henwoodite. 

 Chem. News, vol. xxxiv. p. 173. 



Letter pointing out that what Major Ross has described as a " new 

 test for cupric phosphate " is an old method due to Berzelius, who used 

 metallic lead, whilst Ross uses oxide of lead. F. W. R. 



Websky, Prof. Ueber die Relation der Winkel zwischen vier Krys- 

 talltlachen in einer Zone und die der Winkel zwischen vier Kan ten 

 in einer Flache. [The Relation of the Angle between 4 Planes 

 in one Zone with that between 4 Edges in one Plane.] Monatsb, 

 Tc. preuss. AJc. Wiss. pp. 4-21. ^ 



Wholly mathematical. 



. Ueber Isomorphie und chemischo Constitution von Lievrit, 



Humit, und Chondrodit. [Isomorphism and Composition of Liev- 

 rite, Humite, and Chondrodite.] Monatsb. k. preuss. jVc. Wiss. 

 pp. 201-210. 



