NON-MATHEMATICAL SCIENCES 181 



stances precisely conform to it? May there not 

 be, as I suggested before, some missing link 

 between living and non-living things? Having 

 examined the reproduction of crystals we may 

 next view another analogous phenomenon, 

 which in most cases is still mysterious. It has 

 long been known that chemical processes are 

 sometimes enormously accelerated by minute 

 traces of foreign substances. Such remarkable 

 action is named catalysis, but this, as Poincare 

 would say, "is not to solve the difficulty but 

 only to baptize it." Nevertheless, giving a name 

 to a phenomenon does indicate that we have 

 recognized its existence and its generality, and 

 when we state a problem clearly we are already 

 part way toward its solution. 



Now one of the most interesting kinds of 

 catalysis is the one in which a reaction is accel- 

 erated by one of its own products, so that a long 

 time may elapse before anything happens, but 

 if that product begins to form, or is introduced 

 from without, the reaction goes faster and 

 faster. This autocatalysis has not long been 

 known, but we already realize that it is of ex- 

 tremely frequent occurrence, and doubtless we 

 shall know much more about it in the near 



