1S13 -J Scientific Intelligence. . 46/ 



Article XII. 



SCIENTIFIC INTELLIGENCE; AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Pyrodmalite. 

 _ Some years ago a mineral was discovered in the mine of Bjelke 

 in Verme land, a province of Sweden, situated or. the north side 

 or the lake Venner. This mineral was observed to have the 

 property of giving out the odour of muriatic acid when heated 

 On that account it was distinguished by the name of pyrodma- 

 lite. The following description of it, which was drawn up by 

 Assessor 1.6. Gahn, of Fahlun, is translated from HmameA 

 bam mg till en Mineralogisk Geografi bfver Sverige, p. 1 75 



Ihe colour of pyrodmalite is commonly yellowish-brown, 

 passing into greenish ; internally, it is light greenish-yellow It 

 occurs crystallized in regular six-sided prisms without any ter- 

 minating pyramids. It is composed of plates lying upon each 

 other in a direction perpendicular to the axis of the prism 

 Principal fracture, splendent; cross fracture, uneven, and with- 

 out lustre ; opaque ; semihard ; it is scratched by steel The 

 crystals are often several inches long. Specific gravity 3-081 

 Before, the blow-pipe it becomes dark reddish-brown, and emits 

 the odour ot muriatic acid. It then melts into a black slag and 

 at last a small bead is obtained, more or less attracted by the 

 magnet. It dissolves readily, and in considerable quantity in 

 glass of borax, and gives a colour indicating the presence of 

 manganese and iron. In phosphate of ammonia-and-soda it 

 dissolves with great difficulty. Its constituents are silica lime 

 iron manganese, and muriatic acid. It occurs in the mine o! 

 Bjelke mixed with iron ore, calcareous spar, and black crvstal- 

 Iized malacohte. 



Pyrodmalite was analyzed last summer by Mr. HisilHref He 

 found its constituents as follows :— 



Sk •;•• 35-4 



Oxide of iron 32*6 



Oxide of manganese 23*1 



Alumina q.q 



Muriatic acid q.$ 



Loss 1 ,q 



100-0 

 It would be difficult to form a conception of the composition 

 of this mineral if it be a chemical compound. The muriatic 

 •CM can neither be united with the iron nor the manganese,, as 



2 2 



