SAMARIUM, GADOLINIUM, ETC. 359 



SAMARIUM, GADOLINIUM, ERBIUIVI, 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,t as 150.7 in maximum. The first regular series of determina- 

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



oxide. , Data as follows : 



i 



! S-m.^O^. Sm.^iSO^)^. Per cent. Sm.fl^. 



1.6735 2.8278 59.180 



r.9706 3-33ot 59- '75 



1.1122 1.8787 59.201 



1.0634 1.7966 59-190 



.8547 1.4440 59-190 



.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.fii. Sin.jj^SO ^■^. Per cent. Svi.fi ■^. 



1.0467 1.7675 59-219 



1.0555 1-7818 59.238 



I. 0195 I. 7210 59-225 



Mean, 59,227, ± .0038 

 Hence Sm = 149.328. 

 Combining the two series, we have — 



Cleve 59. 1865, = .0025 



Bettendorff 59-227, =b .0038 



General mean 59.1 99, rt .002 1 



Hence, if SO^ = 79.465, ± .00175, 



Sm =z 149.127, ± .0115. 



If = 16, Sm = 150.263. 



According to Demaryay,!] samaria contains an admixed earth whose 

 properties are yet to be described. 



* Arch. Sci. Phys. et Nat. (3), 3, 435. 18S0. 



t Journ. Chem. Soc, June, 1883. 



t Journ. Chem. Soc, Auguist, 18S3. Conipt. Rend., 97, 94. 



g Ann. Chem. Pharm., 263. 164. 1891. 



II Conipt. Rend., 122, 728. •1896. 



