16 
M. Bonsdorft' on tlie AmpMholes. 
ash, or soda in excess. The titanate is separated from the car- 
bonate by cooling, and forms a crystallised stratum, partly be- 
low the melted carbonate. The capacity of saturation of the 
titanic acid is 16.97 ; that is, the base contains half as much 
oxigen as the acid, The neutral titanates are in a great degree 
decomposed by water, which produces super-titanates, but 
which M. Rose has never been able to obtain at a fixed degree 
of combination, probably because the water decomposes them 
successively. M. Ro.se has also examined the blue oxide of tita-* 
Ilium, but he has not been able to determine its composition. 
This chemist has also employed the sulphuret of carbon to 
obtain several other metals in the state of sulphurets, which have 
not been known under that form. M, Berzelius suggested to 
him to examine in that way the Tantalum^ the composition of 
which had been determined by M. Berzelius, conjointly with Messrs 
Gahn and Eggertz, by the reduction of the oxide in a crucible 
of charcoal. If the metal combines with the charcoal, the result 
cannot be exact. M. Rose has undertaken this inquiry. The 
oxide of tantalum gives a greyish sulphuret of tantalum, the 
combustion of which appeared to indicate that the oxide of tan- 
talum contains a little more oxigen than the reduction with the 
charcoal had indicated. M, Rose is at this moment occupied in 
the inquiry, 
6. Researches respecting the Amphiholes^ hy M. de Ronsdorff, 
M. Bonsdorff has particularly studied those minerals which 
crystallise in the form of the Amphibole. He found that the 
pure amphiboles are composed of 1 atom of trisilicate of lime, 
combined with S atoms of bi silicate of magnesia, 
and also, that these two bases, the lime and the magnesia, may 
be mutually replaced, and may also be replaced by other iso- 
morphbus bases, particularly the protoxides of iron and manga- 
nese. The amphiboles often contain other foreign substances. 
The fluoric acid is rarely wanting in them, and appears to be 
combined with lime, of which we then find an excess propor- 
tional to the quantity of fluoric acid. A great number of am- 
phiboles contain also alumine, and as the quantity of that earth 
increases, that of the silex diminishes; whence M, Bon^^dorff 
concludes, that the first may, in the quality of an electro-nega- 
