80 URANIUM, ANTIMONY, CHROMIUM, c. 



columbic acid, and my determination of its ato- 

 mic weight,, correspond exceedingly well. 



There is no reason, therefore, to doubt that 

 the atomic weight of columbium is 18 ; and that 

 columbic acid is a compound of 1 atom colum- 

 bium and 1 atom oxygen. 



SECT. VII. 



OF THE ATOMIC WEIGHT OF TITANIUM. 



Discovery TITANIUM, in the metallic state, was discovered 

 titanium, by Dr. Wollaston, in 1822, in the slag at the 

 bottom of the iron smelting furnace at Merthyr 

 Tydvil, in South Wales ; and he determined and 

 described its properties with his usual sagacity 

 and precision.* It has the form of small smooth 

 cubes, having a red colour, exceedingly similar 

 to that of copper. The cubes are hard enough 

 to scratch rock crystal, and cannot be fused by 

 the highest temperature which can be raised by 

 the blow pipe. Its specific gravity, as deter- 

 mined by Dr. Wollaston, is 5 '3. It is brittle 

 conducts electricity. From the situation in 

 which it occurs, we may infer that it does not 

 combine with iron, and Dr. Wollaston tried in 

 vain to unite it with lead, tin, silver, and copper. 



* Phil. Trans. 1823, p. 17. 



y 



