204 PETROLOGY. 



Dawson, Dr. J. W. Notes on the Phosphates of tlie Laurentian and 



Cambrian liocks of Canada. Quart. Journ. Geol. Soc. vol. xxxii. 



pp. 285-291. 



Names Lower Silurian horizons yielding phosphatic nodules of copro- 



litic origin, probably derived from animal food. Describes Laurentian 



apatite, also regarded as of coprolitic origin. W. H. D. 



Doelter, Dr. C. Die Bestimmung der petrogr aphis eh wiehtigeren 



Mineralien durch das Mikroscop, eine Anleitung zur mikrosko- 



pischen Gesteinsanalyse. [Determination of Minerals by the 



Microscope.] Pp. 36. 8vo. Vienna. 



An elementary sketch of the method of observing thin sections, e. g. 



with polarized light, and of the determination of minerals by their 



optical properties, combined with the outline of their sections, form of 



twinning, enclosures, &c. Lists of uni- and bi-axal crystals are given, 



and 5 tables of detailed application of the above means for the detection 



of the commoner mineral constituents in thin rock-slices. E. B. T. 



Doelter, Dr. C, and R. Hoernes. Osservazioni chimico-genetiche suUe 

 Dolomiti del Tirolo Meridionale. [Chemico-genetic Observations 

 on the S. Tyrol Dolomites.] Boll. li. Com. geol. Ital. vii. pp. 41- 

 51. Translation of the paper noticed in the Geological Eecoed 

 for 1875, p. 210. 



Douville, H. Les etudes lithologiques en France. [Lithologic Studies 

 in France.] Bev. Sci. x. pp. 377-381. 



Notice of recent researches on the microscopic structure of rocks in 

 France. Adopts the theory that the texture is in immediate relation 

 with the age of rocks ; thus the acid rocks in order of appearance are 

 crystalline or granitoid, compact or lithoid (porphyries, &c.), vitreous 

 or retinoid ; these are further divided. E. B. T. 



Duvillier, — . Analyse des nodules des schistes du Devonien supe- 

 rieur de Glageon (Schistes de Frasne). [Analysis of Nodules from 

 the U. Devonian Schists of Glageon (Frasne Schists).] Ann. Sac. 

 Geol. Nord, t. iii. p. 33. 



Egleston, Dr. T. Eefractory Materials. ^ Iron, n. s. vol. viii. pp. 297, 



431, 486. (Amer. Inst. Min. Eng.) 

 A description of fire-clay, gannister, &c. 



Ferretti, Ant. Considerazioni sui prodotti minerali del territorio di 

 Scandiano. [Mineral Products of Scandiano.] Boll. B. Com. geol. 

 Ital. vii. pp. 132-139, 218-223. 



Notes on hydraulic limestone, sulphur, manganese, ruin-marble, &c. 

 found in the district. 



Fouque, — . Determination des mineraux microscopiques des roches. 

 [Microscopical Analysis of Rocks.] Bev. Sci. t. xi. pp. 589-596. 



