SIR WILLIAM CROOKES ON SCANDIUM. 377 



desiccator over sulphuric acid it contains one molecule of water. Dried in the air it 

 contains two molecules of water. 



Analysis. 



(1) 6'252 gr. of scandium laevo- tart rate, dried in a desiccator for twenty-four hours, 



left on ignition 1'785 gr. of scandia, = 1'1564 gr. of scandium. 



(2) 7'912 gr. of scandium Isevo-tartrate, dried in a desiccator, left on ignition 



2 '2 50 gr. of scandia, = T4570 gr. of scandium. 



Theory. Experiment. 



(1)- (2). 



Sc. . . . 44-100 17-99 18-50 18'42 



C 4 H 5 O 7 . . 165-040 67-31 



81-50 81-58 



2H 2 O . . 36-032 14-70 



245-172 100-00 lOO'OO lOO'OO 



SCANDIUM MESO-TARTRATE. 



CH(OH)COO. 



I >Sc(OH),H,O. 



CH(OH)COO / 



Scandium meso-tartrate is prepared by gently warming a slight excess of scandium 

 hydroxide with aqueous meso-tartaric acid, and then boiling the filtered solution. 

 The meso-tartrate comes down as a white granular precipitate. It is well washed 

 with boiling water and dried over sulphuric acid in a desiccator for twenty-four hours. 

 In this state it contains one molecule of water. 



Analysis. 



4'899 gr. of scandium meso-tartrate yielded on ignition 1"460 gr. of scandia, 



= 0"9455 gr. of scandium. 



Theory. Experiment. 



227-156 100-00 lOO'OO 



The analysis of the compounds of scandium with tartaric acid and its isomers has 

 been complicated by the tendency to form basic salts admitting of no simple formulae. 

 Thus, both the tartrate and laevo-tartrate occasionally form salts containing 



VOL. OCX. A. 3 C 



