242 MINERALOGr. 



Smith, J. L. Gas Wells in Pennsylvania. Ann. Chim. Phys. t. viii. 



p. 56(3 ; Abstract in Proc. Inst. Civ. Eng. vol. xlvi. pp. 355, 356. 

 Analyses of natural gases. 



. Aragonite on the surface of a meteoric iron, and a new 



mineral (Daubreelite) in the concretions of the interior of the 



same. Amer. Journ. ser. 3, vol. xii. pp. 107-110 ; Chem. Neius, 



vol. xxxiv. no. 875, pp. 87, 88. 



The first mineral is shown by physical characters and analysis to be 



aragonite ; and the author regards it as formed subsequently to the fall 



of the meteorite. The second is a black lustrous crystalline mineral of 



the composition — sulphur 37'62, chromium 62*38. T. G. B. 



Sohncke, Dr. Leonhard. Die unbegrenzten regelmtissigen Punkt- 

 systeme als Grundlage einer Theorie der Krystallstruktur, [The 

 unlimited regular Dot-system as a Foundation of a Theory of 

 Crystal-structure.] Verh. nat. Ver. Karlsruhe, Heft vii. pp. 83 ; 

 2 pis. 



Sorby, H. C. On some hitherto undescribed Optical Properties of 



Doubly Eefracting Crystals. Proc. R. Soc. vol. xxvi. pp. 384- 



386. 



Preliminary notice of a new refractometer, as described by Dr. 



Roystou-Pigott in vol. xxiv. p. 393, the principle of which the author 



considers might, with advantage, be applied to the determination of 



the index of refraction of minerals. R. B. N. 



Sorby, H. C, and P. J. Butler. On the Microscopical Structure of 

 Amber. Micr. Journ. vol. xvi. pp. 235-231, pi. clviii. 



Very thin sections of this substance exhibit many cavities from 

 TTkTo ^^ "3"¥oTro ^^ ^^ ^^^^^ ^^ diameter. Por convenience these are 

 divided into three kinds : — 1, filled with fluid; 2, containing both liquid 

 and gas ; 3, filled with gas. The probable mode in which these cavities 

 have been formed is investigated, and also the behaviour of the various 

 parts of the section under polarized light. The important bearing of 

 this examination upon the study of the minute cavities in minerals is 

 noticed. * E. T. N. 



Soret, J. L., and E. Sarasin. Sur la Polarisation rotatoire du 



Quartz. [Rotary Polarization of Quartz.] ArcJi. Sci. Phys. Nat. 



t. liv. pp. 253-264, [Prom Abstract in Phil. Mag. ser. 5, vol. ii. 



pp. 475, 476.] 



Describes the results of experiments on the light of sodium, and 



tabulates the measurements for the solar lines D^ and D^, by Pizeau 



and Poucault's method. T. G. B. 



Spiller, John. On the occurrence of native Calcium Chloride at 

 Guy's Cliffe, Warwickshire. Journ. Chem. Soc. ser. 2, vol. xiv. 

 pp. 154-159. 



