MINERALOGY. 229 



Contaius numerous analyses of minerals, rocks, waters, and natural 

 gases, 



Gonnard, F. Mineralogie du Departement du Puy- de-Dome. [Mi- 



neralog}' of Puy-de-D6me.] Ed. 2, pp. 192. 12mo. Paris. 

 The geological position and localities of each mineral species found 

 in the district are given. 



Grattarola, Prof. Giuseppe. Note mineralogiche. Boll. R. Com. 

 geol. Ital. vii. pp. 323-345. 



Notes first minerals from fresh localities in Elba. Idrocastorite is 

 described as new, formula given =12*5 SiOj, 2-5A1203, CaO, 10 H2O. 

 Pinite pseudomorphic after andalusite by alteration, is noted, &c. 

 Passes then to Tuscany, where some new localities are noted ; among 

 these is goslarite, from near Maesa Marittima, formed from decomposi- 

 tion of blende. E. B. T. 



Groth, P. Physikalische Krj^stallographie, und EinleHung in die 

 kryst allograph ische Kenntniss der wichtigeren Substanzen. [Phy- 

 sical Crystallography, and Introduction to CrystaUographic Know- 

 ledge of the more important Substances.] Pp. 530, 557 woodcuts, 

 and 3 plates (1 coloured). 8vo. Leipzig. 

 Part i. treats of the physical characteristics of crystals in general, 

 without reference to their form, and includes their density, elasticity, 

 cohesion, hardness, and molecular vibrations, as well as their optic, 

 thermic, magnetic, and electric properties. Part ii. is devoted to geo- 

 metrical and physical crystallography. Part iii. describes and explains 

 the instruments employed and methods adopted in physico-crystallo- 

 graphical researches, and concludes with a comparative table of symbols 

 used in the crystallographic systems of Naumann, MiUer, and Levy. 

 The author's object is to supply a course of crystallographic study suffi- 

 cient for those who have not the advantage of professional or other 

 instruction. T. W. D. 



Hartley, W. N. On the presence of Liquid Carbon Dioxide in Mineral 

 Cavities. Joum. Chem. Soc. ser. 2, vol. xiv. pp. 137-143; with 

 4 figs. 

 By observing the critical point of the liquid in certain crystals of 

 quartz, shows that this liquid is condensed carbon dioxide, often asso- 

 ciated, however, with water. Contact of a carbonate with a hot solution 

 of silica would under considerable pressure yield carbon dioxide, which 

 on cooling would condense, along with water, to the state of liquid in 

 the cavities of the silica. F. W. R. 



. On Variations in the Critical Point of Carbon Dioxide in 



Minerals, and Deductions from these and other Facts. Jouim. 



Chem. Soc. ser. 2, vol. xiv. pp. 237-250 ; 3 figs. 



Gives variations in the critical point of carbon dioxide, from about 



25'''5 to 33°*7, as observed in cavities in topaz, tourmaline, sapphire, 



beryl, and rock-crystal. Contains inferences as to the formation of 



