*4ff Extracts from the third Volums of 



Analysis of the Fibrous Broivn Sulphate of Barytcs. 



The fossil of Neu-Leiningen, in the Palatinate, con- 

 founded with calamine, seemed worthy of being analysed ; 

 and it now appears to be a sulphate of barytes, and not an 

 oxide of zinc. Its external characters, so difTerent from 

 those of the other species of the sulphate of barytes, ought 

 ta make it be considered as a particular species. 



The description given of it by M. Karsten is as follows : 



Fibrous sulphate of barytes is of a chestnut brown colour 

 on the fracture, when fresh. 



Its form holds a mean between that in rognons and that 

 in clusters. Its surface and lustre cannot be determined, 

 because the fossil seems to have been exposed to friction. 



Internally it is not very brilliant. It has a greasy aspect. 



Its fracture is fibrous; and the fibres diverge like thr 

 Beards of a quill. 



The fragments are irregularly angular, and the edges are 

 pellucid. 



It is soft and heavy: its specific gravity is 4080. 



Three hundred grains of this pure sulphate of barytes, 

 the lime adhering to which had been separated by acetous 

 acid, pounded, and boiled with 600 grains of the carbonate 

 of potash, decomposed and redissolvcd in muriatic acid, 

 erystallized in tablets of muriate of barytes. 



When redissolved in water and remixed with the first 

 solution of potash, which contained the sulphuric acid of 

 the decomposed fossil, and in wiiich the excess of potash 

 had been saturated by acetous acid, the sulphate of barytes 

 v.as precipitated. When washed and collected it weighed 

 297 grains. 



A solution of prussiate of potash, poured into the water 

 of the washing, gave a slight indication of iron. 



Analysis of the Manganese Ore of Slescld, in tJie Harz. 



This ore, which has for matrix a white sulphate of 

 barytes, is distinguished from other ores of n)angancse by 

 a greater metallic splendour, and bv the size of its pris- 

 matic crystals with four planes, which are sometimes more 

 thnn two inches in length. Jt was formerly believed that 

 this metallif" splendour arose U\>m a considerable quantity 

 of iron; but the analysis of M. ivhiprolh has proved that, 

 )l CQiitains none of that metal. 



A hun- 



