22 SIR WILLIAM CROOKES ON SCANDIUM. 



SCANDIUM FLUORIDE, 



Sc 2 F 6 . 



Ignited scandia is attacked by aqueous hydrofluoric acid, forming a semi-transparent 

 gum-like mass, which on boiling changes to a fine white precipitate. This is difficult 

 to filter, as it has great tendency to run through. 



When hydrofluoric acid is added to a solution of scandium nitrate or sulphate, a 

 white precipitate comes down. On boiling it becomes milky, resembling the above- 

 described precipitate. 



The. fluoride dried over sulphuric acid is anhydrous. It slightly loses weight at a 

 red heat, and at a yellow heat it frits together, fusing with difficulty before the 

 blowpipe. 



Strong sulphuric acid imperfectly decomposes scandium fluoride. It is completely 

 decomposed by fusion with potassium bisulphate. ; the melt dissolves in acidulated 

 water, and the solution mixed with ammonia deposits scandium hydroxide. 



Analysis. 



8'!). r )f> grs. of scandium fluoride, decomposed by fusion with potassnun bisulphate 

 and precipitated by ammonia, gave 0-0305 grs. of scandia, = 3'9091 grs. of 

 scandium. 



Theory. Experiment. 



So, 88-2 43-02 43'G5 



F K .... 114-0 50-38 56-35 



202-2 I ()()()() 100-00 



SCANDIUM CHLORATE. 



Aqueous chloric acid saturated with scandium hydroxide forms at first a clear 

 colourless liquid; evaporation on the water-bath decomposes it, with evolution of 

 chlorine. On further evaporation, crystals like long needles form on cooling, 

 and the mother-liquor becomes a gummy amorphous mass in which, after standing, 

 appear long needle-shaped crystals. These crystals probably are the perchlorate. 



SCANDIUM PERCHLORATE. 



Aqueous perchloric acid easily dissolves scandium hydroxide or carbonate, and the 

 solution evaporated over the water-bath separates into a felt-like mass of rhombic 

 needle-shaped crystals. 



