18 92.] Mineralogy and Petrography. 515 



Texas, Pa., and is the same as that examined by Cooke 1 in 1867. 

 Three new forms were observed on it, viz. : oo P2, JP2 and iP. The 

 prism JP2 is very characteristic and is seldom wanting. The author 

 also corrects the axial ratio for mordenite to a : b : c = .401 : 1 : .4279. 

 /3 = 88° 29' 46", and briefly describes skeleton crystals of hematite 

 from Durango, Mex., filled with cassiterite and pseudomorphs of the 

 latter mineral after the former. 



Mineralogical News.— Dr. Hoffman* mentions a quartzite from 

 the North shore of St. Joseph Island, in Lake Huron, whose joint 

 planes are coated with limonite containing numerous tiny spherules 

 composed of a nucleus of silica, coated with a humus-like substance, 

 which in turn ia overlain by a layer of metallic iron. The spherules 

 form 58.85% of the mixture. They have a density of 6.8612 and the 

 following composition: Fe - 88.00 ; Mn = .51 ; Ni = .10;Co = 

 .21 ; Cu = .09 ; S = .12 ; P = .96 ; C = ? ; insoL res. = 9.76. The 

 insoluble residue consisted of little concentric bodies with the composi- 

 tion : Si0 2 = 93.95 ; A1 2 3 = 1.13 ; Fe 2 3 = 1.02 ; CaO = .62 ; Mg 

 == .31 ; Loss = 2.97. 



Analyses of uraninite from two new localities are given in a 

 recent paper by Hillebrand 3 . The first is that of a specimen obtained 

 from Marietta, Greenville Co., S. C, and the other that of one from 

 the Villeneuve Mine, Ottawa, Quebec. Neither of the two was pure. 



UO UO. Th0 2 Zr0 2 Ce0 2 (La. etc.) Yt. etc. CaO PbO H,0 

 2.05 6.16 .41 3.58 und. 

 1.11 2.57 .39 11.27 1.47 



Results of the analyses of the same mineral from Llano Co., Texas, 

 and from Johann-georgenstadt, Sax., show the presence of nitrogen in 



Williams 4 has discovered anatase crystals in a jointed slate from five 

 miles South of Bremo Bluffs, Buckingham Co., Va. The crystals are 

 small and are associated with pyrite and quartz, which cover the faces 



