3B26 MispellaneouB Intelligence. 



12. Brown Oxide of Chromium. — This compound, first formed by 

 Vauquelin, is considered by M. ]\Iaiis as a combination of the prot^ 

 oxide of chrome and chromic acid ; it may be formed by mixing a 

 Bolution of chromate of potash with protochloride of chromium, or 

 by boiUng chromic acid with protoxide of chrome ; when the sub- 

 stance in question is digested with acetate of lead, chromate of lead 

 and acetate of the protoxide of chrome is formed. Potash also 

 changes it into chromic acid and green oxide of chrome. Arsenic 

 acid carefully added produces arseniate of chrome and chromic acid. 



The brown precipitate produced by mixing chromate of potash 

 and chloride of chromium, is decomposed by being repeatedly 

 washed with water, especially if hot ; chromic acid is removed and 

 green oxide of chrome remains. Chromate of chromium is decom- 

 posed also in a similar manner, water removing each time more 

 acid than oxide. Hence a great uncertainty about the composition 

 of these substances. 



If the chromate of ammonia be heated gradually to the point of 

 decomposition, the salt is decomposed suddenly, pure deutoxide 

 remains, which dissolves readily in concentrated acid. This oxide 

 has been mistaken for the combination of protoxide and chromic 

 acid If, at the moment of decomposition, the temperature be 

 suddenly raised, a luminous appearance is produced. 



Chromic acid dissolves the hydrate or the carbonate of chrome 

 readily, producing a dark brown solution, which, when evaporated, 

 leaves a brittle resinous-looking mass; it is deliquescent and dis- 

 solves in alchohol. 



A solution of the deutoxide may also be effected in chromic 

 acid, which being analyzed, gave 



Chromic acid, 72.21 or 1 atom. 

 Oxide, 27 79 or 2 atoms. 



Peroxide of iron behaves in the same manner, and produces a 

 similar compound with chromic acid, as the deutoxide of chromium. 

 The compound consists of Peroxide of iron, 25,06 

 Chromic acid, 74.94 



or one atom base, two atoms of acid. — Ann.de Chimie, xxxvi. 216. 



13. A ccension of Arsenical Cobalt Ore — M. Boullay has had 

 occasion to observe that, having pulverised a large quantity of 

 arsenical cobalt ore, the mass of powder heated of itself, without any 

 application, and ultimately took fire. 



14. Artificial Ultramarine. — M. Guy-Lussac stated to the Aca- 

 demy of Sciences, at Paris, that ultramarine had been composed and 

 manufactured for sale by M. Tunel, at a price less than half that 

 previously paid for this pigment. M. Tunel keeps his process a 

 secret at present, but is said to have been led to the discovery by 

 the analysis of M. CUment. — Le Glohe. 



15. Ancient Cannon raised from the Sea. — ^A fisherman of 



