Dr. Wollaston on Metallic Titanhtm. 19 



Having bi'okcn out some of these crystals for expei'imcnt, 

 I found them all apparently attracted by a magnet ; but ob- 

 serving that they had still small portions of slag adherent to 

 them, they wei'e next digested in muriatic acid, which, by dis- 

 solving the iron from their surfaces, soon freed them from 

 their deceptive appearance of magnetism. 



The cubes thus purified are not acted upon by muriatic 

 acid. 



Nitric acid has no action upon them. 



Nitro-muriatic acid does not dissolve them. 



Boiling sulphuric acid does not affect them. 



Before the blow-pipe they are utterly infusible. A con- 

 tinued heat oxidates them, and they become purple or red at 

 the surface, according to the degree of oxidation, or depth to 

 which it penetrates. 



Borax has no action upon them, but only cleans the sur- 

 face from an}' oxide that may be formed. Neither does the 

 addition of subcarbonate of soda produce more effect than 

 borax alone. 



Nitre, aided by a strong heat, oxidates them rapidly : but 

 unless the heat be long continued, the effect is only super- 

 ficial. 



The combined action of nitre and borax together soon ef- 

 fects their solution, as the latter dissolves the oxide as fast as 

 it is formed, and presents a clean surface for fresh oxidation. 

 But as these salts do not unite by fusion, the addition of soda, 

 as a medium of union, considerably shortens the process. The 

 fused mass becomes opake in cooling, by the deposit of a 

 white oxide, which may either be previously freed of the salts 

 by boiling water and then dissolved in muriatic acid, or the 

 whole mass may be at once dissolved together. 



In either case alkalies precipitate from the solution a white 

 oxide, which is not soluble by excess of alkali, either pure, or 

 in the state of carbonate. By evaporating the muriatic solu- 

 tion of the oxide to dryness, at the heat of boiling water, it is 

 freed of any redundant acid, and the muriate which remains 

 is perfectly soluble in water, and in a state most favourable 

 for exhibiting the characteristic properties of the metal. 



Inliision of galls gives the well known colour of gallate of ti- 

 tanium. The colour occasioned by adding triple prussiate of 

 potash is red, as observed by Laugier, and so nearly resembling 

 that of the gallate, that I do not think any difference that I can 

 discern is to be depended upon as constant. It differs from 

 prussiate of cojiper by inclining to orange instead of purple, 

 while the colour of prussiate of uranium is rather brown than 

 red. 



C 2 Since 



