Manchester Memoirs, Vol. li. (1907), No. 6. 



Elements. 



Atomic Group j Calculated 

 Weights. Position. ! At. Wt. 



Difference. 



Group IV r 



Mean (firsl 



) positio 



n, 3'i7- 





Carbon 



Zirconium 



Cerium 



C 

 Ti 

 Zr 

 Ce 



Th 



I2'00 

 48-IO 

 90-60 



140-25 



232-50 



3' 2 4 

 4-08 

 3-11 

 4*94 



5-62 



11-84 



46-49 



90-77 



i37*S 2 



225-92 



+ o - i6 

 4-2'6i 



- 0*17 



4-2-73 



4-6-58 



Thorium 



Group IV„. 



Mean (second) position, 4-09. 



Carbon ... 

 Titanium 

 Zirconium 

 Cerium ... 



Thorium 



C 

 Ti 

 Zr 

 Ce 



Th 



48-10 



90-60 



140-25 



232-50 



3' 2 4 

 4-08 

 3-11 

 4-09 



5-62 



1379 



48-11 



93-22 



140-24 



228-44 



-179 



- O'OI 



— 2*62 

 + o - oo 



4-4-06 



Group V. 





Mean position, 



4"3 2 - 





Nitrogen 



N 



14-04 



4'22 



14-24 



- 0'20 



Vanadium 



V 



51-20 



5-15 



48-78 



4-2-42 



Niobium 



Nb 



94-00 



4-39 



93^3 



4-0-I7 



Praseodymium 



Pr 



140-50 



4-l8 



140-92 



-0*42 



Tantalum 



Ta 



183-00 



3"67 



184-83 



-I-8 3 



