SIR WILLIAM CROOKES ON SCANDIUM. 



(2) 17 - 9 5 6 gr. of 18 -hydrate were heated carefully until the temperature rose to 

 250. At this point the white salt became slightly brown. It weighed 

 1T265 gr., showing a loss of 6'691 gr. of water. 



Theory. Experiment. 



} 



(1). (2)- 



5141 



L 6274 



94-86J 



37-26 



893-15 100-00 100-00 lOO'OO 



Scandium iodate loses three molecules of water when kept for some time in a 

 desiccator, and leaves a hydrate containing 1 5 molecules of water, 



Sc(I0 3 ) 3 , + 15H 2 0. 



15 - 415 gr. of 18 -hydrate scandium iodate were dried for some time over sulphuric 

 acid. The 15-hydrate into which it had changed was dissolved in hydrochloric 

 acid and precipitated with ammonia. After ignition the scandia weighed 

 1'2G1 gr., = 0'8166 gr. of scandium. 



Theory. Experiment. 



839-10 100-00 100-00 



When the 18-hydrate scandium iodate is dried for several hours in a vacuum 

 desiccator over sulphuric acid, it loses five molecules of water and leaves a 13-hydrate, 



Sc(I0 3 ) 3 , + 13H 2 0. 



(1) 7 "6 8 4 gr. of 13-hydrate scandium iodate, prepared as described, were fused 



with excess of potassium bisulphate ; iodine was evolved, and when the whole 

 was in quiet fusion it was allowed to cool. The melt was boiled out with 

 water, an excess of ammonia added, and the resulting scandia separated. It 

 weighed 0'643 gr., = 0'4164 gr. of scandium. 



(2) 5-537 gr. of 13-hydrate scandium iodate were dissolved in acid, precipitated by 



ammonia as already described, and the resulting scandia collected. It weighed 

 0-463 gr., = 0-2998 gr. of scandium. 



(3) 18-104 gr. of 13-hydrate scandium iodate, dried at 250, lost 5'205 gr. of 



water. 



