4 i2 SCIENCE PROGRESS 



Kelvin speaks of at all — the numerical expression of experimental 

 results — but numbers deduced from these on what may be 

 entirely false assumptions. We must not forget that, as has so 

 often been said, we cannot get out of the mathematical mill more 

 than we put into it. If we put in doubtful assumptions we can 

 get out only doubtful conclusions. When we look at the palatial 

 mathematical edifices erected out of chemical facts by Arrhenius, 

 Ostwald and Nernst on this side of the Atlantic and by their 

 disciples Stiegiitz, Acree, Noyes and Jones on the other side, 

 we shudder to think of the terrific downfall should the founda- 

 tions give way — such an occurrence is not impossible. 



Consider our theories of solution. Almost all chemists regard 

 electrolytes in solution as consisting of a number of units, some 

 of which are active, others inactive — that the active ones have 

 a fixed, unalterable activity while active and that change of 

 activity of the solution, from whatever cause, is occasioned by 

 a change in the mere number oi active units. This is the assump- 

 tion underlying almost the whole of the work that has been 

 done on solutions of electrolytes and yet the assumption may 

 be fundamentally wrong. We may find some day that all the 

 units of the solute are potentially active and that change of 

 condition changes not their number but their potential activity. 

 Such a discovery would relegate to the rubbish-heap hundreds 

 of tons of published matter. 



