TITANIUM. 87 



titanic acid by the combustion. A little of it 

 may have continued in the metallic state, or 

 have been only converted into protoxide of ti- 

 tanium. 



This experiment certainly gives us a near ap- 

 proximation to the atomic weight of titanium, 

 though the want of exact agreement between the 

 parts of it shows us that it is not quite accu- 

 rate. 



(2.) It occurred to me that I might probably A 



.,.,.. * tionof ti- 



come tolerably near the truth by acidifying me- 

 tallic titanium by means of a mixture of potash 

 and nitre, and determining the increase of 

 weight. I took a quantity of metallic titanium, 

 which I had procured from the slag of the fur- 

 nace at Merthyr Tydvil, and mixing it with 

 potash and nitre, exposed it to a red heat 'in a 

 platinum crucible. The titanium was acidified, 

 but the nitre and potash had acted on the cru- 

 cible, blackened its interior [surface, and oxy- 

 dized 11 grains of the platinum which were 

 mixed with the titanic acid. I attempted to se- 

 parate this oxide of platinum from the titanic 

 acid ; but the result was not quite satisfactory. 

 I therefore repeated the experiment in a small 

 green glass retort. 4< grains of metallic titanium, 

 37 '05 grains of nitre, and 5'88 grains of caustic 

 potash, were mixed together, and kept for half an 

 hour in a dull red heat in a green glass retort, the 

 weight of which had been previously determined. 



