1823.] M, Rose on Titanium. 871 



upon, substances containing a known quantity of oxygen were 

 submitted to experiment. A mixture of silica and carbonate 

 of potash was heated together in a small platina crucible ; and 

 it appeared by every trial, that the quantity of oxygen in the 

 carbonic acid expelled was equal to that in the silica employed, 

 as indicated by the experiments of Berzelius, the mean of result 

 being 60-3 and the mean of M. Rose's 50-27. 



M. Rose states the results of five experiments, in which car- 

 bonate of soda and titanic acid were heated together. He has 

 not reduced them to centesimal parts, but by doing so it will 

 appear that he was less fortunate than with the experiments on 

 sihca. Supposing 100 parts of the titanic acid to have been 

 used, the quantity of oxygen of the carbonic acid expelled by it, 

 and consequently that of the titanic acid itself, would have 

 amounted in 



Exper. 1 33*639 per cent. 



2 37-019 



3 36-034 



4 35-024 



5 33-534 



It is evident that this method did not succeed ; the compound 

 obtained by heating titanic acid with carbonate of soda, M. Rose 

 considers as a neutral titanate, which is decomposed by water, it 

 taking away part of the potash. 



Compounds of Titanic Acid tvith Acids. 



All chemists who have made experiments upon titanium have 

 admitted the existence of salts, in which the oxide of titanium 

 is considered as a base. According to them the sulphates, 

 nitrates, and muriate, crystallize after evaporation. M. Rose 

 supposes, however, that what has been considered pure oxide of 

 titanium, is a compound of titanic acid with the alkalies, and he 

 imagines their titanic salts are combinations of the alkalies with 

 the acids employed. In fact, when acidulous titanate of potash 

 is dissolved in muriatic acid, cubic crystals of chloride of potassium 

 are obtained ; and the author is of opinion that no compounds 

 of titanium exist, in which the titanium can be considered as the 

 base. When indeed acidulous titanate of potash is dissolved in 

 muriatic acid, some acids throw down precipitates which con- 

 tain no potash, and do not possess the properties of salts. 

 These precipitates redden litmus paper strongly, and ihey must 

 be considered as insoluble double acids, analogous to the com- 

 pounds of tartaric acid w^ith some other acids, which have been 

 described by Berzelius. 



When acidulous titanate of potash is dissolved in muriatic 

 acid, and the solution is diluted with water, white precipitates 

 are obtained by adding the sulphuric, arsenic, phosphoric, oxahc, 

 and tartaric acids, but no precipitate is formed by the addition 



2 b2 



