134 Chronicles of Science. [Jan., 



In external characters it resembles the Tuscan miemite, but in 

 composition it is a hydrous silicate of magnesia, iron, and alumina. 

 Its name is suggested by the decrepitating sound which the mineral 

 emits when thro\\Ti into water, especially if the hquid be warm. 



The Professor also caUs attention to a new meteorite which has 

 been ploughed up on a farm near Losttown, Cherokee County, 

 Georgia.* It weighs 6 lbs. 10 oz., contains abundance of nickel, 

 and when etched exhibits the " Widmaunstattian figures." 



Perhaps the chemist, rather than the mineralogist, wiU be inte- 

 rested in a paper by Mr. J. E. Keynolds,t in which he attempts to 

 introduce a new mode of expressing symbolically the chemical 

 constitution of the mineral silicates, — a mode which he conceives 

 to be free from the objections which may fau4y be urged against 

 the notations recently introduced by Odling, Frankland, Dana, and 

 others. 



Signor Bombicci describes, among other Italian minerals, a new 

 calcareous serpentine to be called BarettUe, after its discoverer 

 Baretti ; and an impure aUophane remarkable for containing lead, 

 and hence named Plumhoallojyhane.X 



Many analyses of the triclinic felspars, labradorite, and ohgo- 

 clase, have been published by Herr K5nig, of rreiberg.§ The 

 chemical examination of some ItaHan augites wiU be found ui a 

 recent memoir by Yom Eath.|| 



Eammelsberg has published a paper on the composition of 

 apophyllite and okenite,1f and another on the phonohte of Mont 

 Dore.** Finally, we may mention that Dr. Sandberger announces 

 the discovery of tridymite in the trachyte of the Drachenfels.tt 



New WorJcs on Mineralogy. — It has been weU said that over 

 the portals of Mineralogy might fitly be inscribed the famous 

 motto placed by Pythagoras at the entrance to his school of 

 philosophy, " Let no one enter here who is ignorant of Geometry." 

 Indeed, to master the difficulties of crystallographic science, which 

 early beset the path of the mineralogical student, a fair acquaint- 

 ance with solid geometry is unperatively demanded ; whilst the 

 study of some of the more refined systems w^ould be undertaken 

 in vain without the assistance of spherical trigonometry. Every 

 one, however, does not faU in love with 



'' The hard-graiued Muses of the Cube and Sphere ; " 



and hence it can hardly be expected that crystallography wiU 



* ' Pilliman's Journal,' Sept., 1868, p. 257. 



t ' rhil. Mag,' Oct., 18G8, p. 274. 



i ' Atli della societa ital. di scienzo nat.,' XI. 



§ Zdtsch. d. deut. Gcol GcsoU. 18GS, p. 365. || Ihid.. p. 265. 



\ Ibid., p. 441. ** Ibid., p. 258. ft ' Ncucs Jahrbuch,' 18G8, p. 723. 



