SAMARIUM, GADOLINIUM. ETC. 



SAMARIUM, GADOLINIUM, ERBIUM, AND YTTERBIUM. 



The data relative to the atomic weights of these rare elements are 

 rather scanty, and all depend upon analyses or syntheses of the sul- 

 phates. 



SAMARIUM. 



Atomic weight given by Marignac,* without details, as 149.4, and by 

 Brauner,f as 150.7 in maximum. The first regular series of determina- 

 tions was by Cleve, J who effected the synthesis of the sulphate from the 

 oxide. Data as follows : 



Sm 2 O 3 . Sm.i(SOJ 3 . Per cent. 



1.6735 2.8278 59- l8 



i.97o6 3.3301 59- '75 



I.II22 1.8787 59-201 



1.0634 1.7966 S9- 1 9 



.8547 1.4440 59.J90 



7447 1-2583 59-183 



Mean, 59.1865, .0025 



Hence Sm = 149.038. 



Another set of determinations by Bettendorff, after the same general 

 method, gave as follows: 



Sm.,O. A . Sm^SO^. Per cent. Sm. 2 O 3 . 

 1.0467 1.7675 59-219 



1.0555 1.7818 59. 2 38 



1.0195 1.7210 59.225 



Mean, 59,227, .0038 



Hence Sm = 149.328. v 



Combining the two series, we have 



Cleve .................................. 59. 1865, = .0025 



Bettendorff ............................. 59.227, .0038 



General mean 59.1 99, =h .002 r 



Hence, if S0 3 = 79.465, .00175, 



Sm = 149. 127, =b .01 15. 



If 0=16, Sm = 150.263*. 



According to Demarcay.|| samaria contains an admixed earth whose 

 properties are yet to be described. 



* Arch. Sci. Phys. et Nat. (3), 3, 435. 1880. 



t Journ. Chem. Soc., June, 1883. 



1 Journ. Chem. Soc., August, 1883. Conipt. Rend., 97, 94. 



gAnn. Chem. Pharm., 263, 164. 1891. 



j| Compt. Rend., 122, 728. 1896. 



