PETR0L06Y. 211 



rocks indicated by names based on the horizons of the beds cut through, 

 as : — carbophyre, kohlophyre, triaphyre, juraphyre, etc. G. A. L. 



Eck, Andre. Analyses of Chalk. Rev. Geol. t. xi. p. 46. 

 Gives the composition of hard chalk from Rilly and Verzy, and of 

 soft chalk from llheims. The last contains the least carbonate of lime. 



Egleston, Prof. T. Analysis of Rocks. Trans. Amer. Inst. Mm. Eng, 

 vol. iii. pp. 94-98. 



Alludes to Cordier's mechanical analysis of rocks, and to Fouque's 

 partly mechanical and partly chemical process. The latter consists in 

 reducing the rock to powder, separating the coarser parts from the fine 

 powder by means of graduated sieves, and then separating those parts 

 which contain iron by means of an electro-magnet. R. B. N. 



Fellenberg, L. von. Analysen zweier Porphyre aus dem Maroggia- 

 Tunnel im Tessin. [Analyses of two Porphyries from Maroggia Tun- 

 nel, Canton Tessin.] Zeitsch. deutsch. geol. Ges. Heft ii. pp. 422-429. 



Fouque, F. Depots salins des Laves de la derniere eruption de 

 Santorin. [Saline Deposits in the Lavas of the last eruption at 

 Santorin.] Oompt. Rend. t. Ixxx, pp. 832-834, with remarks by 

 Ch. Sainte-Claire Deville, pp. 834-836. 



Analyses are given ; and each writer offers a theory as to the forma- 

 tion of the deposits. 



Frazer, Prof. P. On Thin Sections of the Traps of the Mesozoic 

 Basin. Proc. Ac. Nat. Sci. Philadel. pt. i. p. 72. 



. Notes on the character of the Lower Silurian Slate at their 



Outcrops. Ibid. p. 76. 



On the Traps of the Mesozoic Sandstone in York and Adams 



Cos. Proc. Amer. Phil. Sac. vol. xiv. pp. 402-429. 

 — . Description of some Microscopic sections of Trap dykes in 

 the Mesozoic Red Sandstone of Pennsylvania and Connecticut. 

 Ibid. pp. 430-447. 



On some thin Sections of the Lower Palecozoic and Mesozoic 



Rocks of Pennsylvania. Trans. Amer. Inst. Min. Eng. vol. iii. 



pp. 327, 328. 



Allusion made to the rare occurrence of syenite in the Red Sandstone. 



Frickhinger, Hermann. Wenneberg-Lava aus dem Ries. [Lava 



from the Wenneberg.] Verh. Wurzb.phys.-med. Ges. n. F., Bd. viii. 



Noticed in K JaJirh. Heft iv. pp. 429-431. 



Describes a stony lava from the Wenneberg, near Alerheim in the Ries, 



which has been variously named. It consists principally of a green 



fibrous mineral, believed to be hornblende, and contains granules of 



quartz with fluid-enclosures. An analysis is given. * F. W. R. 



Gtimbel, Dr. C. W. [Wenneberg Lava.] N. Jahrh. Heft iv. 



pp. 391-393. 

 The rock described as Wenneberg lava is a basalt, rich in plagioolaso, 

 and much decomposed. Microscopic description given. 



p 2 



