2 28 Literary and Philosophical Society. 



If mathematical truth has begun out of few axioms, so 

 also have national and social laws. Let us think of the 

 enormous mass of law-books possessed by all nations, the 

 enormous number continually making and being unmade ; 

 and is it not still clear that in almost all cases ' Do as you 

 would be done by ' means enough ? So with the great 

 atomic law of Dalton ; it must expand and become more 

 complex, and other branch laws may be added, but it is 

 an amusement to see the men who labour to get over 

 the fundamental one making use of the same conclusions 

 and darkening their own counsel. We find one writer 

 calling Dalton's laws hypotheses, and Avogadro's a theory ; 

 where would Avogadro's have been without Dalton's ? 

 We find then isomorphism and isomerism thus exalted, 

 but surely they also are developments of Dalton's thoughts. 

 The forms of expression * atomic volume ' and * specific 

 heat of atoms ' would not only not have been used, but 

 probably the inquiries they indicate never would have been 

 made without the fundamental idea of 'the weight of 

 ultimate particles of bodies.' 



It has been said that the farther we go in one direction 

 the greater we prove the circle of knowledge to be, and 

 it is added that the wider its range, the greater the part 

 that is unknown ; there may be a limit to that, but we may 

 say that the farther the idea leads us the greater it 

 must be, and the great generalisation made by Dalton has 

 not only led us very far, but promises to lead us still farther 

 and probably longer than any single idea given us in 

 physical sciences. 



The simplicity of Dalton's law threw all the specula - 

 tions of the chemists to the winds and corrected their 

 analyses. He saw simply that bodies combined by adding 



