Intelligence and 3Iiscellaneoics Articles. 517 



WI Tar.ON THE QUANTITATIVE ESTIMATION OF MANGANESE. 



To the Editors of tJie Philosophical Magazine and Journal. 



GE>fTLEMEN, 



Perhaps the following facts may facilitate the quantitative esti- 

 mation of manganese. I find, contrary to what is stated in works 

 on chemical analysis, that carbonate of manganese is not decom- 

 posable at ordinary temperatures by the oxygen of the atmosphere, 

 but remains permanently white if it have been precipitated without 

 an excess of carbonate of potash or carbonate of soda. When an 

 excess of either of these reagents is used in its precipitation, the 

 excess of the alkali decomposes a portion of the metallic carbonate, 

 and becomes a sesqui- or a bicarbonate. If a bicarbonate of the 

 alkali be used to precipitate carbonate of manganese, the precipitant 

 may be added in excess and the precipitate exposed to the air with 

 impunity. Manganese resembles the magnesian class of metals in 

 its carbonate being undecomposable by caustic ammonia ; hence 

 either of the carbonates of the volatile alkali may be used with effect 

 to precipitate a carbonate of manganese that will remain persistent in 

 the atmosphere. Carbonate of manganese, when exposed to any 

 high temperature approaching near to redness, passes at once into 

 the black oxide without apparently going through any intermediate 

 state of oxidation. 



I remain, &c. 



Richard Laming. 



ZB'tr 'bnozi^i 71.1^13 ^o bns - IT .'^ol- \o 



REMARKS UPON A RECENTLY FOUND MASS OF METEORIC ^RONi' 



^(ri'l ■cfiHi 9+» 0-t \iHlU- BY G. ROSE. 



In the spring of 1 850, during the leveling of a sandy hill for the 

 railroad on the left bank of the Blackwater near Schwetz on the 

 Vistula, a mass of iron was found about four feet beneath the surface 

 of the soil at the junction of the upj)er sand with the subjacent loam. 

 Tlie mass of iron was somewhat fissured, and a small portion could 

 be broken off without difficulty, which, to be certain that it consisted 

 of iron, was forged. The rest was cleft into pieces at Schwetz. 

 After the mass had been recognized as meteoric iron, the whole was 

 sent to Berlin. The separate portions, when rearranged, still exhibit 

 the original form of the mass, which is somewhat that of a rectan- 

 gular prism, completely rounded off at the edges. The height of 

 this prism was about 9 Prussian inches, the sides of the base 3^ and 

 4 inches, the longitudinal circumference 24 inches, and the breadth 

 17^ inches. A fissure which traversed the fragments runs nearly 

 parallel to a plane, passing through the diagonally-opposite longest 

 edges of the base. The weight of the entire mass was 43 lbs. 4 02. 

 The outer sides of tlie fragments arc rounded and coated with hy- 

 drated oxide of iron ; the internal surfaces, which formed the sur- 

 faces of old fissures, were also oxidized ; but in parts the fracture 

 was jagged. One of the surfaces of section has been polished and 

 etched, and now exhibits very beautiful Widmannstattean figures. 



