SIR WILLIAM CROOKES ON SCANDIUM. 25 



Theory. Experiment. 



466-46 100-00 lOO'OO 



ANHYDROUS SCANDIUM SULPHATE, 

 Sc 2 (S0 4 ).,. 



When the hydrated sulphate is heated to 250 it loses the whole of the water and 

 becomes anhydrous. Its composition now is Sc 2 (SO,) a . 

 At a bright yellow heat all the sulphuric acid goes off. 



Analysis. 



(1) 30-716 grs. left on ignition Ll'092 grs. of scandia. 



(2) 18-907 grs. left on ignition 6'827 grs. of scandia. 



Synthesis. 



(3) C'817 grs. of ignited scandia, converted into sulphate, yielded 18 '907 grs. of 



scandium sulphate. 



Theory. Experiment. 



376-38 100-00 lOO'OO lOO'OO lOO'OO 



When the anhydrous sulphate is heated to dull redness it loses one molecule of 

 SO 3 , and becomes a basic salt of the composition 



Sc 2 0(SO,) 2 . 



Synthesis. 



4'622 grs. of ignited scandia were dissolved in strong sulphuric acid, the excess 

 of acid driven off by heat, and the dry sulphate heated to dull redness-. It 



weighed 10 '121 grs. 



Theory. Experiment. 



Sc 2 O 3 136-20 45-97 45"67 



2S0 3 160-12 54-03 54'33 



g __ _^___^__ 



296-32 100-00 100'OQ 

 VOL. CCIX. A. E 



