MINERALOGY. 709 



Tetradymite. Composition discussed, P. A. Genth, Am. Phil. Soc. Philad.j Oct. 2. 

 Tetrahedrite. Crystals from Colorado, Liweh, Zs. Kr., X, 488. 



Lake City, Colo., analysis, Guntb, Am. Phil. Soc. Pliilad., Oct. 2. 

 TiEMANNiTE. Froni Utah, in tetrahedral crystals (like sphalerite), also analysis, S. L. 



Peufield, Am. J. Sc, xxix, 449. 

 Tin, NATIVE. From New South Wales, with platinum, etc., F. A. Gonth, Am. Phil. 



Soc. Philad., Oct. 2. 

 TiTANiTE. From Lewis County, New York, apparent cleavage due to twinning, G. 

 H. Williams, Am. J. Sc, xxix, 486. 

 Occurrence (and analysis) with other minerals in the District of Columbia, G. P. 



Merrill, Proc. U. S. Nat. Mus., 351, 1885. 

 Lehigh County, Pennsylvania, analysis, Knerr and E. F. Smith, Am. Ch. J., vi, 



412. 

 Statesville, N. C, analysis, Genth, Am. Phil. Soc. Philad., Oct. 2. 

 Topaz. Ci"ystal from Alabaschka in the Ural, Griinhut, Zs. Kr.,x, 263. 



Discussion of paper by Griinhut (Zs, Kr.,ix, 113), with additional lists of angles, 



V. Kokscharow, Min. Russlands, ix, 97. 

 Urals, crystals with vicinal planes, etc., F. J. Wiik, Oefv. Fiusk. Vet. Soc, xxvii. 

 Pyro-electricity, Friedel and Curie, Bull. Soc. Min., vin, 16. 



Stoneham, Me., examination, also of alteration products, F. W. Clarke and J. S. 

 Diller, Am. J. Sc, xxix, 378; analysis, Genth, Am. Phil. Soc. Philad., Oct. 2. 

 Tourmaline. Investigation of Pyro-electricity, Eiecke, Nachr. k, Ges. Wiss. Gottiu- 



gen, Dec. 30, p. 405. 

 Tridymite. Crystals from Krakatau, G. vom Rath, Zs. Kr.,x, 174. 

 TURQUOIS. General description, von Kokscharow, Min. Russlands, ix, 83. 



Pseudomoi'ph after apatite, G. E. Moore and V. von Zepharovich, Zs. Kr., x, 240. 



UiNTAHiTE. A variety of asphaltum from the Uintah Mountains, Utah, W. P. Blake, 



Eng. & Mining J., Dec 26. 

 Uraninite. Found in Black Hills, Dakota, L. W. Stillwell, Am. J. Sc, xxx, 82. 



Vanadinite. Crystals from New Mexico, analyzed and described, F. A. Genth and G. 



vom Rath, Zs. Kr., X, 460 ; Am. Phil. Soc. Phila., April 17. 

 Wanlockhead, Scotland, Analysis, Genth, Am. Phil. Soc, Phila., Oct. 2. 

 Vesuvianite. Discussion of measurements by himself, Zepharovich, and others, with 



lists of calculated angles, N. Kokscharow, Miss Russlands, ix, 150. 



Wad. From Wester Silfberg, Sweden, analysis, Weibull, Min. petr. Mitth,, vii. 



Xenotime. Crystals from El Paso County, Colorado, W. E, Hidden, Am. J. Sc, xxix, 

 249. 



Zeolites. Discussion of the optical properties, pyrognostics, &c., of the various 

 species of the group with a view to developing the methods of distinguishing 

 between them, Lacroix, Bull. Soc. Minn., viii, 321. 

 Zircon. Crystal with iP from Burgess, Canada, W. E. Hidden, Am. J. Sc xxix, 250. 

 Chemical examination, Linneniann, Ch. News, Liii, 220,2.33,240. 



EXPLANATIONS OF ABBREVIATIONS EMPLOYED. 



Am. Ch. J. — American Chemical Jcurnal, Baltimore. 

 Ann. Ch. Phya. — Annales de Chimio et de Physique, Paris. 

 Am. J. Sc. — American Journal of Science, New Haven. 

 Ann. Mill. — Annales des Mines, Paris. 



Am. Phil. Soc. Philad. — American Philosophical Society of Philadelphia. Proceedings. 

 Per. Ak. Berlin. — Sitzungsberichte der kais. preuss. Akadcmje lU'.r Wissenschafteu, 

 Perlin. 



