Geology and Mineralogy. 319 



makes it a new mineral under the name hydi 

 been derived from the decomposition of castorite. It is in part 

 compact, in part it is made up of an aggregate of fine needh 4ike 

 crystals. Its composition is shown by the analysis: Silica 59*59, 

 alumina 21-35, lime 4-38, water 1 4-66=99-98. 



Guanajuatite. — The sulpho-selenide of bismuth from Guana- 

 juato Movie,,, partially described by Castillo, (1873), and later 

 ribed by Frenzel (Jahrb. Min., 1874, 679), was named 

 in the Second Appendix to Dana's Mineralogy (1875, p. 

 22). It seems, however, that the same mineral was at first named 

 U'«in<iju«t'itt bv Fernandez, who described it in full in the Guana- 

 juato paper, " La Republica" for July 13th, 1873. The latter 

 name should consequently be accepted instead of the name fren- 

 zelite. The description by Professor Fernandez differs from that 

 of others in that he makes the mineral solely a bismuth eelenide 

 (Bi t Si .), and attributes the presence of a small amount of sul- 

 phur, shown in his analyses, to the admixture with a little pyi-ite. 

 material analyzed by Frenzel received the formula 2Bi 2 Se 3 4- 



fc 1 



Profess* 



same locality, the Santa Catarina mine at Guanajuato. It has a 

 lead-gray color, and is compact in structure. Its hardness is a 

 Jttle less than that of calcite; its specific gravity 6-428-6-45. 

 The results of several analyses upon material more or less pure 

 Jed to the conclusion that the chemical composition is expressed 

 by the formula Bi 3 Se. E - s - D - 



12. Zeitschrift filr Kry8talloqr> ' • TO U 



No. l, 1877. — The first number of this new Journal, recently 



(See p. 162 of this volume.) It contains the following original 



ot some immense enstatite crvst: • "}", XN ■ 



U Brogger and G. vom Rath ; on the crystalline form ot I 

 b J A. Schrauf; on the regular grouping of quartz crystals ,n cab 

 .te, by E. S. Dana; on the dimorphism of hydrochinon and para- 

 nitro phenol, by O. Lehmann ; a manganese variety of tremohte, 

 b y g. A .Koenig ; on the form of crystals of barium snip hat. . . ftc., 

 byH. Baumhauer; on the schorlomite from the Kaiserstuhl, by 

 A - Knop. In addition to the above articles, a series of notices 

 and extract u in number, and covering as many 



Pages, follow. These are derived from a great a ariet; 

 and form not the least valuable part of the number I nder the 

 able editorship of Professor Groth, it cannot be doubted that the 

 ~""7 Journal will always maintain the high character it has at its 



m Ueber den inneren Zusammenhang der verschiedenen Krys- 

 fUgestallten des R Schaot : 61 pp. 4to with 



J v « Plates. Frankfort, 1876.— The memoirs previously published 

 b Y ^ Scharff upon the interior crystalline structure of several 



