SIR WILLIAM CKOOKES ON SCANDIUM. 



Theory. Experiment. 



369 



2Sc . 

 3Pt . 

 12CN 

 15H 2 O 

 1H 2 



(1). 



7-05 

 42-50 



49-53 



50-45 50-47 



1363-656 100-00 lOO'OO 



Theory. 



100-00 



Sc a [Pt(CN)J 3 72-26 



15H 2 O 19-82 



1H 2 O 1-3-J 



5-94 



0-66 



100-00 



Experiment. 

 (3). 



72-26 



1975 

 1-25 



5-99 

 0-75 



100-00 



Normal scandium platinocyanide is not quite stable when its solution is heated 

 and evaporated. During re-crystallisation the solution, at first clear and colourless, 

 deposits a yellow powder and gives an odour of hydrocyanic acid. Analyses of the 

 yellow deposit have not yet given me concordant results ; roughly it contains 23'5 per 

 cent, of scandium and 6 per cent, of platinum. The analytical results with the 

 normal platinocyanide given above show an excess of scandium and a deficit of 

 platinum. This may be the result of slight decomposition during re-crystallisation, 

 with production of a trace of the yellow compound. 



SCANDIUM MONO-CHLOROACETATE, 

 (CH 2 ClCOO) 2 ScOH + 2H 2 O. 



Scandium hydroxide, ground and well shaken with a cold aqueous solution ot 

 monochloracetic acid, dissolves slowly and almost completely. The clear filtered 

 solution, evaporated in the cold over sulphuric acid, deposits a crystalline crust, 

 appearing under the microscope as flower-like groups of stellate crystals, and showing 

 good colour when examined by polarised light. These crystals are permanent in dry 

 air, and lose no water at 100. On being heated they decompose quietly, and at a 

 red heat leave a white residue of scandia. 



VOL. ccx. A, 3 B 



