28 INORGANIC EVOLUTION. [CHAP. II. 



" It is abundantly clear that if the so-called elements, or, more 

 properly speaking, their finest atoms those that give us line spectra 

 are really compounds, the compounds must have been formed at a 

 very high temperature. It is easy to imagine that there may be no 

 superior limit to temperature, and therefore no superior limit beyond 

 which such combinations are possible, because the atoms which have 

 the power of combining together at these transcendental stages of heat 

 do not exist as such, or rather they exist combined with other atoms, 

 like or unlike, at all lower temperatures. Hence association will be a 

 combination of more complex molecules as temperature is reduced, and 

 of dissociation, therefore, with increased temperature, there may be 

 no end." 



In 1878 I went back to the study of the changes in the line spectra 

 in relation to the changes observed when known compounds were dis- 

 sociated, and after discussing certain objections, I submitted the con- 

 clusion that the known facts with regard to the changes in line 

 spectra " are easily grouped together, and a perfect continuity of 

 phenomena established on the hypothesis of successive dissociations 

 analogous to those observed in the cases of undoubted compounds."* 



It is thus seen that the conclusions to which my spectroscopic work 

 up to the year 1880 had led me, tended in exactly the same direction 

 as that indicated by more purely chemical inquiries thus referred to by 

 Berthelot in that year : 



"L'etude approfondie des proprie'tes physiques et chimiques des 

 masses e'le'mentaires, qui , constituent nos corps simples actuels, tend 

 chaque jour d'a vantage a les assimiler, non a des atonies indivisibles, 

 homogenes et susceptibles d'eprouver seulement des mouvements 

 d'ensemble, . . . il est difficile d'imaginer un mot et une notion 

 plus contraires a 1'observation ; mais a des Edifices fort complexes,, 

 dou^s d'une architecture specifique et anime's des mouvements intestins 

 ires varies."! 



* Proc. Roy. Soc., vol. xxviii, p. 179. 

 f Comptes rendu*, 18SO, vol. xc, p. 1512. 



