176 THE ANATOMY OF SCIENCE 



shall we find a better illustration of a level 

 chance. Therefore when a process forms billions 

 of such molecules it would seem like an extraor- 

 dinary fluctuation from the average if we 

 should ever find a discernible excess of the right- 

 hand or left-hand molecules. Never, in fact, has 



FiGUEE 27 



Right- and Left-handed Molecules 



such an excess been found in reactions which 

 start wdth substances which are not themselves 

 predominantly right- or left-handed, and which 

 are not subjected to some pecuHarly asymmetri- 

 cal environment. If the reaction produces right- 

 and left-handed molecules it produces them in 

 equal quantities. By crystallizing the product 

 crystals are formed which are themselves right- 

 or left-handed, but the two varieties occur in 

 equal amounts. 



