1902.] 



The Classification of the Elements. 



93 





171 



172 



173 Yb 



174 

 175 

 176 

 177 

 178 

 179 

 180 



181 



182 



]83 Ta 



184 W 





202 



203 



204 Tl 



205 

 206 



207 Pb 



208 Bi 



209 



210 



211 





229 



230 



231 



232 Th 



233 

 234 

 235 

 236 



237 



238 



239 



210 TJ 



from that of bromine by only a single unit, the change does not appear 

 to be an unjustifiable one. 



The same argument applies to tellurium in the following period. 

 Personally, I entertain no doubt that the atomic weight of this 

 element will ultimately prove to be considerably lower than that of 

 iodine. 



It is unnecessary to go into further details — the table is self-explana- 

 tory ; but it may not be superfluous to point out that the characteristic 



