W. O. BAKER 



Thus these theories provide a kind of continuum for the 

 advance of science, so utterly different from the situation 

 implied by the current term "breakthrough." That term is both 

 blasphemy and barbarism applied to science, for the continuum 

 is the important quality in the nurturing of basic research and 

 in living with the paradox or choice. 



Another powerful way to harmonize the freedom of the 

 individual scholar in science with the achievement of useful 

 and desired products is to be sure that everybody speaks the 

 same language. This is a simple convenience which is often 

 overlooked. It means that basic expressions of scientific concepts 

 ought to contain common units and, hopefully, common mean- 

 ings. Again, unifying physical theories, which early helped to 

 define parameters in basic terms, are of great importance. For 

 instance, nearly everyone would agree that a system of "elec- 

 tronics" has been the most vital feature of growth in chemical 

 science and understanding in the past century. One of the first 

 successes in identifying the versatility of bonding in carbon 

 compounds was Kekule's concept of aromatic or benzenoid 

 hydrocarbons. This appeared in 1866. For nearly ninety years 

 after that, elaborate extensions of his concept accepted electrons 

 as synonymous with electric charges. The ingenious modern 

 notions of resonance, by Pauling, and mesomerism, by Ingold 

 and co-workers, were linked in most minds with the distribu- 

 tion of the old-time electrons. Only now is arising clear realiza- 

 tion of the relative functions of positive and negative distribu- 

 tions of charge. Largely brought out by the semi-conductor 

 theories referred to above, we see that such charge distributions 

 may govern the structures and reactions of vast classes of chem- 

 ical compounds, but are not properly represented dynamically 

 by the circulation of electrons. The circulation of positive and 

 negative charges, with proper wave mechanics and with the 

 positive holes playing a prominent role, is much more illuminat- 



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