274 Professor Ossann's Chemical Examination^ ^'C. 



specific gravity than platina, and probably belong to the tessii- 

 lar system. The osmium, on the contrary, appears to belong to 

 the electro-negative metals, which possess a hexagonal crystalli- 

 zation, such as arsenic^ tellurium and antimony. 



4. Silver-white Flat Grains. — They appear to be palladium. 



Concluding Remark. — In the portion of platina-sand I exa- 

 mined, the large half was ferruginous platina, the smaller com- 

 mon or true platina. The remaining grains composed about 

 J J 5th part of the whole. 



Chemical Examination of Tourmalifie. By Prof. C. G. Gmelin. 



vJTmelin arranges the Tourmaline under three subdivisions, 

 these depending on the chemical composition. The following- 

 are the results of his analyses : 



A Tourmaline which contains Lithion. 

 Three varieties of this kind were examined : 1. Red tourma- 

 line or rubellite, from Rozna, in Moravia ; its specific gravity 

 = 2.96 to 3.02. 2. Red tourmaline, from Perm, in Siberia. 

 Specific gravity =r 3,059. 3. Celandine green tourmaline, from 

 Brazil. Specific gravity — 3.079. The following table gives 

 their constituent parts : 



B. Tourmaline xvhich contains either Potash or Soda, or bothy 

 without Lithion, and a minute portion of Magnesia. 



Of these the following were analysed: 1. Black tourmaline, 

 from Bovey, in Devonshire, which occurs along with quartz and 



» With trace of Potash. 



