498 Hackh — Modification of the Periodic Table. 



determinations are constantly added and the reference 

 recorded. In doing this work, I was surprised to find 

 how very fragmentary our knowledge is ; with the excep- 

 tion of the specific gravity and the melting point, which 

 are known of nearly every element, there are hardly any 

 data of properties in the literature for more than forty 





4 



5 6 



7 







1 



2 



3 4 







v 



IVb 



Illb 



lib 



lb 







III' 



C© Pr Nd 



H&HE EARTH METALS 

 Sm Eu Gd Tb Jfy Ho Er 



Tm' Tfo" Yb lu 



V" 



Va 

 IVa 

 Ilia 

 Ha 



la 



III' 



Sn 



Qe 



Si 



C 





ES 

 I 



Br 



CI 



F 







Ce 

 Zr 

 Ti 

 Si 

 C 



NON MfiTA 



INERT ELEMENTS 



Kr 

 At 



Ne 

 He 



LIGHT METALS 



Sb 



As 



P 



N 



Te 



Se 



S 







Cs 

 Rb 

 K 

 Na 

 Li 



Ba 



Sr 

 Ca 

 % 

 Be 



la 



Y 



Sc 



Al 



B 



H 



Ti -V Cr 



HEAVY METALS 

 Mi Fe Co Ni Cu 



In Ga Ge 



IV 



Zr Cb Md 



Hu Ph pd Ag 



Cd In Sn 



IV* 



V 



lu Ta TAT 



Os Ir Pt Au 



Hg Tl Pb 



V 



Tl Pb Bi Po 



PbRa ■* RaF 



N RaE^ 

 /PbTh\^ /ThC'\ 



(PbAc < AcC'l 



v \RaD/ VRaCV 

 /ThD\ /ThCW 



(AcD U AcCf 



\RaC7 , \RaC/ 



/ThBW /ThA\ 



RADIOACTIVE ELEMENTS 

 Nt 



/ThEm\ 



Ha Ac Th Bv U 



/ThX\ /RaTh\ /- 



'AcX ) < (RaAc - 



Ua / /r Vlo J+\$,_ 

 /MsT ff /- \ 



(Ac < (Uzf 



/ V- / * \Ux" 



[«*■- — te/ . 





VRaEmV ' 



V 



RaB/ 



k \ 



,RaA/ 







\ 



1 





\Ux' 



* — u 



Table VIII. The complete periodic system (elements and isotopes). 



elements ; most of those are limited to twenty and even 

 ten elements. There is still a great field open for physi- 

 cal determinations of element-constants. 



The isotopes of the radioactive elements are given in 

 Table VII, in which the three series of disintegration, 

 e. g., uranium, actinium, thorium, are combined into one. 

 It will be seen, that with the exception of the beginning of 

 these series, the disintegration of all three series is analo- 

 gous from the isotopes of thorium (RaTh, EaAc, Jo) to 



