BARRANDE, FOSSILS FROM BOHEMIA. HAUER, ALUMINA. 15 



300° C. ; and it burns with a bright and yellow flame, with a large 

 proportion of soot. [Count M.] 



On Silurian Fossils /rom Wossek, Bohemia. 

 By M. J. Barrande. 



[Proceedings of the Imp. Geol. Institute of Vienna, January 8, 1856.] 



An interesting collection of fossils was made, chiefly during the sum- 

 mer of 1855, by the Austrian Geological Surveyors in the environs 

 of Rokitzan in the Silurian basin of Bohemia. These are of the 

 more interest as M. Barrande' s search for fossils in this locality had 

 been hitherto unsuccessful. The fossils were found at Wossek,*N.E. 

 of Rokitzan, in M. Barrande' s *' Quartzite stage D," and may be 

 regarded as belonging to the commencement of the Second Bohemian 

 Fauna. They are in a rather imperfect state of preservation and oc- 

 cur in very hard quartzose nodules, remaining on the surface of the 

 ground after the decomposition of the schists in which they were 

 originally imbedded. 



M. Barrande recognized altogether 37 species among these organic 

 remains from" Wossek, trilobites (13 species) being prevalent; and 

 only 5 of these 1 3 species have previously been found with stage D. 

 Cephalopods are very scarce ; there are only 4 species, and the spe- 

 cimens are generally badly preserved. The Gasteropods are repre- 

 sented by 5 species, including the Ribeiria phodadrformiSi Sharpe, 

 which occurs also in the Silurian rocks of Portugal. There are 

 3 species of Acephala ; one of them, RedoniUy being also represented 

 in the Second Silurian Fauna of France. 



The fossil fauna of Wossek also includes 4 species of Brachiopods 

 and 2 of Echinoderms. [Count M.] 



On a method of procuring Alumina. By Chev. von Hauer. 



[Proceedings of the Imp. Geol. Institute of Vienna, January 15, 1856.] 



Pure alumina is best obtained from ammoniacal-alum, or from sul- 

 phate of alumina, wherever, as in England, those salts are produced 

 on a large scale. At Vienna, however, where they are still scarce 

 objects of commercial transaction, chemists are obliged to operate on 

 potash- alum or on kaolin. The alumina extracted from the first of these 

 materials, even in quantities of a few pounds, requires long-continued 

 washing with hot water, sometimes during several weeks, to get rid 

 of the potash adhering to it. The kaolin requires hot concentrated 

 sulphuric acid for its decomposition, so that operations on a large 

 scale are very troublesome and difficult. The Imperial Geological 

 Institute received some time ago specimens of a very pure kaolin, 

 which forms abed of about 6 joch (345*342 acres) between Znaim and 

 Brenditz, in Moravia. The quantity yearly raised is between 6000 

 and 8000 zentners (740,400 to 987,200 pounds avoirdup.), but may 

 be easily augmented, if required, to 20,000 zentners (2,468,000 



