206 



PETROLOGY. 



AcMardi, Ant. d'. Sulla cordierite nel granite normale delF Elba e 

 sulle correlazioni delle rocce graniticlie con le trachitiche. [The 

 Cordierite of the normal granite of Elba and the Correlation of 

 the granitic and trachytic rocks.] Atti Soc. tosc. Sci. Nat. 



AUport, S. On the Classification and Nomenclature of Rocks. Geol. 



Mag. dec. ii. vol. ii. pp. 583-587. 

 Criticises certain names suggested by Mr. Kinahan, and other points 

 connected with nomenclatures often in use. 



Anger, F. Arno. Mikroskopische Studien iiber klastische Gesteine. 

 [Microscopic studies of clastic rocks.] Min. Mitt. Heft iii. pp. 

 153-174. 



Zirkel and Credner have already worked at this subject [see Geo- 

 logical Hecoed for 1874, pp. 199, 200]. Anger has extended his 

 observations to sandstones, slates, and tuft's, and finds that these clastic 

 rocks contain both sedimentary and crystalline constituents. Quartz 

 and mica are the most frequent clastic materials ; calcite is the most 

 common crystalline element. Iron-glance is commonly present, and 

 microscopic crystals of tourmaline (hemimorphic) are frequent in sedi- 

 mentary rocks. Glauconite is not amorphous, but exhibits double 

 refraction. Certain felsite-tuff's are not purely clastic ; the basalt-tuffs 

 of Gleichenberg in Styria are quartziferous palagonite-tufts. The 

 principal constituent of the trass of the Laacher See is leucite. E. W. R. 



Anon. The Phoenix Eire-Brick Works, Tavistock, Devon. Iron, 



vol. vi. n. 8. pp. 104, 105. 

 Analysis of the fire-clay by Dr. Noad. Analyses of other clays (by 

 Prof. Abel) reprinted for comparison. 



. [Argillaceous limestone.] Rev. Geol. t. xii. p. 49. 



Analyses of argillaceous limestone from the commune of Briotij 

 Canton of Levroux (Indre), made at the Ecole des Mines laboratory. 

 The rock is Jurassic. G. A. L. 



. [Cement-stones.] Rev. Geol. t. xii. pp. 50, 51. 



Six analyses of cement-stones from Chapareillan (Isere), Saint- 

 Bauzille-de-Putois (Herault), and Raincy (Seine-et-Oise). 



. . [Analysis of brick-earth from Broin near Seurre (Cote d'Or)j] 



Rev. Geol. t. xii. pp. 57. 



. [Erench fire-clays and earths.] Rev. Geol. t. xii. p. 59* 



Eive analyses of earths from Briou near Yierzon (Cher) and 

 Buzangais (Indre), and of clays from near Amiens (Somme) and 

 Sermaize (Mame). All refractory. ^ G. A. L. 



