KOVEMBER 10, 1911] 



SCIENCE 



643 



I Te Sb Sn In Cd Agr Rh Ru Pd 

 — Lu Yb Tm Er Ho Tb SmEu Od 

 ABC Po Bl Pb Tl Hg Au Oslr Pt ' 



ftXo Cb 2r V Sr Rb Kr 

 Nd Pr Ce La Ba Cs Xo 

 W Ta — — Tu — ,, -^ 



Periodic Table of Atomic Weights with Valence. 



which puts specific volume in the place of 

 atomic volume (at. w./sp. gr.), thus empha- 

 sizing the more important part of the atomic 

 volume graph: the compressibility graph of 

 T. W. Richards, changed to apply only to 

 solids; and the graph of the fusion of the 

 halogen compounds of Thomas Carnelley. 

 These graphs are changed in size only to 

 match the helix; and the exact agreement of 

 the four large curves with the double octaves, 

 the two small ones with the octaves, and the 

 exact space left for the haK octave is a strong 

 confirmation of the naturalness of the helix. 

 Further I have been able, by a very reasonable 

 extrapolation, to prolong backward the atomic 

 volume graph to match exactly the half and 

 quarter octaves, and to show that its natural 



culminations are in the inert gases and not in 

 the alkalis. 



The law of longitudinal condensation is 

 especially interesting. It is only in the 

 middle or K circle (the one containing po- 

 tassium and iron) that density and valence 

 agree from 1 in K to 8 in Fe, so that density 

 divided by valence (D/V) equals unity. In 

 earlier circles D/V is less than 1, so that less 

 matter is condensed into the atom that satis- 

 fies a given amount of H, and in later cir- 

 cles D/V is greater than unity and more 

 matter is condensed into the corresponding 

 atom. Thus the densities of the iron, rubi- 

 dium, samarium and platinum triads are as 

 8:12:16:22+ or D/V = 1:U:2:3, and, if we 

 omit gases and poorly determined elements, 



Nu PrF Cn H Nu 



CI Ne Na Mg AI Si 



Zn Ga Ge As Se Br Ar 



Oa Ir Pt Au 



Tl Pb Bi Po ABC 



Ca So Ti 



Eh Eu Pd Ag Cd In Sn Sb Te I Cr Rb Sr 

 Sm En Gd Tb Ha Er Tm Yb Ln — Xe Cs Ba 



Zr Cb Mo 



Ce Pr Na — 



EaEmThi Eu lo Tb Ea Ur 



