SIR WILLIAM CROOKES ON SCANDIUM. 21 



Analysis. 



(1) 4*235 grs. on ignition left 1*620 grs. of scandia, = T049 grs. of scandium. 



(2) 4'124 grs. were dissolved in water and the scandia precipitated by ammonia. 



The scandia obtained weighed 1*592 grs., = 1*031 grs. of scandium. 



Theory. Experiment. 



(1). (2). ' 



2477 25-00 



75-23 75-00 



354-948 100-00 lOO'OO lOO'OO 



HYDRATED SCANDIUM BROMIDE, 

 Sc 2 Br 6 ,12H 2 0. 



Scandium hydroxide or carbonate dissolves easily in hydrobromic acid, and the acid 

 solution evaporated on the water-bath deposits small rhombic crystals, coloured 

 slightly brown by free bromine and very deliquescent. These crystals were collected 

 on filter-paper and dried by pressure between folds of paper frequently renewed. 

 They were then put into a silica weighing bottle, and dried in a desiccator over 

 sulphuric acid. 



Analysis. 



(1) 29-753 grs. of the hydrated bromide gave on ignition 5'068 grs. of scandia. 



(2) 29-753 grs. of the hydrated bromide lost at 120 6'207 grs. of water. 



784-152 100-00 lOO'OO 



When the hydrated bromide is heated in an air-bath to 120 it loses 9 molecules of 



water and becomes 



Sc 2 Br e ,3H 2 = ScA,6HBr. 



Analysis. 



23'546 grs. of the dried bromide left on ignition 5'068 grs. of scandia. 



Theory. Experiment. 



622-008 100-00 lOO'OO 



