[ 7* ] 

 XII. Intelligence and Miscellaneous Articles. 



PHOSPHATE OF IRON, MANGANESE AND SODA. 

 BY M. A. DAMOUR. 



I^^HIS mineral was recently found among the pegmatites of the 

 environs of Chanteloub, near Limoges, by I\I. Mathieu, a 

 mineral-dealer. 



Wlien viewed in mass, its colour is clove-brown ; its fracture 

 lamellar and sliining ; and in some places, which appear altered, it is 

 chatoyant like diallage. It possesses three rectangular cleavages, 

 which leads to the conclusion that the mineral crystallizes in right 

 rectangular prisms. This mineral scratches fluor spar, and is scratched 

 by a steel point ; its density is 3-468. When heated by the blow- 

 pipe on platina, it melts into a non-magnetic globule. With fluxes 

 it gives the reactions of manganese, and gives water wlien heated in 

 the tube. Hydrochloric acid dissolves it readily, a little chlorine 

 being evolved. 



A qualitative analysis showed that the mineral is composed essen- 

 tially of phosphoric acid, peroxide of iron, and oxide of manganese 

 and soda, combined with a small quantity of water. 

 The mean of six analyses gave — 



Phosphoric acid 41 '25 



Peroxide of iron 25 "62 



Oxide of manganese .... 2;V08 



Soda 5'47 



Water 2-65 



Silica 0-60 



Peroxide of manganese .. T06 



99-73 

 The physical characters and chemical composition of this mineral 

 distinguish it from all previously known phosphates, and show that 

 it should be classed as a distinct species. — Comptes Rendus, No- 

 vembre 1847. 



ANALYSIS OF COLUMBITE FROM THE ENVIRONS OF LIMOGES. 

 BY M. A. DAMOUR. 



This mineral species, which has hitherto been found in a few places 

 only, has been met with in a quarry near Chanteloub. The speci- 

 men, below described, was confounded with specimens of w^olfram 

 and triplite, which M. Mathieu had collected. Its colour, hardness 

 and great density, induced M. Damour to believe that it contained 

 columbic acid. It occurs in the form of nuclei imbedded in yellow- 

 ish-white felspar. It is of a tariushed bluish-black colour on the 

 surface; the fresh fracture is shining and glossy; its powder is 

 black, approaching gray. It scratches glass, and its density is 7-651. 

 It does not fuse by the blowpipe ; but when heated on charcoal with 

 tartrate of potash, it yields globules of tin. Acids do not act upon 

 it. Analysis gave — 



