TABLE OF SOME DATA, RELATING TO THE ETHYLSULPHATES OF THE RARE EARTH-METALS. 



Yttrium 

 Lanthanium 



Samarium 

 Europium 

 Gadolinium 



Qysprosium 

 Erbium 



: 0.5058 

 : 0.5063 

 : 0.5072 



1 : 0.5050 

 1:0.5053 



12 Neqytterbium') I : 0.5079 



Observed Forms. 



Specific 

 Weight 

 (at 25° C.) 



1.876 



Parameters. 



Refractive Indices. 



1.764 ■ 309.80 ' 6.4737:6.5190 'n(i=1.493;n^= 1.480 Almost coloufless 

 1.845 733.27 6.5279: 6.6231 , n„= 1.482;n ,= 1 .473 Colourless crystals 



722.86 

 724.10 

 1.904 I 722.52 

 1 .909 I 722.31 

 1.919 724.07 



702.27 6.4337:6 5303 n„= 1.482;n|, = 1 .474 



6.5033:6.5787 nii= 1.486 

 6.5026:6.5911 'n,= 1.487 

 6.4961:6.5897 .no =1.490 

 6.5016 6.5770 U,= 1.494 

 6.5103:6.5753 nu=l. 490 



= 1.481 

 : 1.484 

 : 1.482 



1.942 720.85 i 6.5007 : 6.5657 %= 1.4S5;n^ = 1 .482 



1.907 I 739.6 6.5553:6,6247 no= 1 .490in^ = 1.480 



2.001 \ 705.59 I 6.4494:6.5293 ]nii=1492;n^^ 1.466 



2.019 I 702.76 i 6.4407:6.5207 no = 1.497:n^= 1.483 j Colourless 



Colourless crystals I 3 



Emeraldgreen cryst. | 4 



Pink crystals I 5 

 Pale yellow crystals 6 

 Colourless 7 



Colourless crystals 8 



Colourless crystals i 9 



Pale rosa crystals ' 10: 



sub 12 however, are all determined with the pure neo-ylterbiumsalt. Finally i 

 James; the measurements gave the same results, as they arc reproduced here in the table. 

 A remarkable fact is the anomalous value of rfj with the c^rjumsalt; however in 

 substance, the same abnormality was every time recorded. 



' well developped crystals also from the oxnie of M. 

 repeated determinations with the often recrystallised 



