446 DR T. THOMSON'S Analysis of some Minerals. 

 It is therefore a compound of 



4 atoms pertersilicate of iron, 

 1 atom tersilicate of manganese. 



8. Sp- Hisingrite. This mineral was discovered in the iron 

 mine of Gillinge, in Sodermanland, and was first described and 

 analyzed by HISINGER in 1810*. 



Its constituents are, 



4 atoms persilicate of iron, 

 1 atom silicate of alumina, 

 4 atoms water. 



9. Sp. Knebilite. This is a name given by DOBEREINER to 

 a mineral of unknown locality, which he described and ana- 

 lyzed f . Its constituents are, 



1 atom silicate of iron, 



1 atom silicate of manganese. 



10. Sp. Pyrosmalite. Discovered in the iron mine of Bjelke, 

 Nordmark in Wermland, Sweden, described by HAUSSMANN, and 

 analyzed by BERZELIUS and HISINGER J, is composed of, 



14 atoms sesquisilicate of iron, 

 5 atoms sesquisilicate of manganese, 

 1 atom sesquichloride of iron. 



* Afhand. iii. 304. -j- SCHWEIGGEB'S Journ. xxi. 49. 



| Afhand. iv. 317. 



