648 



high temperatures, or for H, N and in the gases H„ N„ 0„ 

 which also dissociate at very high temperatures? 



Then — and this is perhaps the most remarkable of our results, 

 which is fully contirmed by what follows presently with respect to 

 the heats of dissociation — the values of l^a rise at once to the 

 greatly increased values from 30 to 40 (instead of from 1 to 11). 

 These increased values are therefore the real valency-attractions, 

 whereas the values found in compounds represent only the so-called 

 rest-values: what still remains for action outside, after the chief 

 valencies are saturate, and have therefore become inactive towards 

 the outside. 



That for the elements of the helium group only the ordinary rest 

 values ai'e found in spite of their atomistic behaviour is of course 

 owing to this that these elements are valence-less.- 



For arsenic only a partially increased value was found, pointing 

 to a dissociation of As< at 7\- to an amount of 207o, whereas 

 phosphorus appeared to be still perfectly normal = P^ at Tk- For 

 Se and Te we found amounts of dissociation (always at Tj^ of 

 307o I'esp. 807o- ï'i the halogen group only a very slight degree 

 of dissociation (5 and JO",,,) was observed for Br, and 1,. As the 

 atoms occur more and more a,9 free atoms, the tn eta I chai'acter Sisserts 

 itself more and more in a group: As^Sb— >Bi; Se— ^Te; etc. 



Besides the rise from to 1.55 and 3.1 for carbon — according as 

 the C-atom is entirely or only paitially shadowed by surrounding 

 atoms or atom groups, to which it is bound — another rise of Y-^a 

 takes place, up to 32, the ten-fold value, when the C-atom has also 

 got released from these bindings, and can occur quite independent as 

 atomistic carbon. Hence the enormously high value of the critical 

 temperature, viz. 6500 abs., which would only have amounted to 

 120° abs. in the case of Cj, as is easy to calculate. The carbon 

 would have become comparable with N,, 0, etc., whereas it is now 

 on a line with a metal that is exceedingly difficult to melt. 



For Tellurium the peculiarity is still found that the normal rest- 

 attraction 9, which is among others found for TeCI^ '), has already 



1) That for TeCl^ the central Teatom does not exert an intercepting influence 

 like C in GCl^, Ge in GeCl^, etc. is owing to the configuration of the molecule. 

 While for GGl^ the four chlorine atoms are regularly situated in the sjoace round 

 the C-atom (in the direction of the four angular points of a tetrahedron), it should 

 be supposed that for TeGl4 the Gl atoms lie in one plane round the central Te- 

 atom. Nor do we find a complete intercepting influence for PClj and POGI3, 

 AsHs and AsCl.3, SbHs and SbGls, which for these substances is probably owing 

 to the compara'iively greater extension of the central atom. For SbClj we find 

 even again the full rest value 9 (Gf. the cited papers in these Proceedings). 



