August 12, 1910] 



SCIENCE 



217 



very diverse chemical formulae of different 

 substances, we find many forms varying more 

 or less from those of the isometric system. 

 Nevertheless, so long as molecules are exactly 

 similar to each other and are arranged in their 

 most compact form, as they will be if given 

 time to adjust themselves to their mutual at- 

 tractions, each molecule will touch its neigh- 

 bors at twelve points just as surely as in the 



case of the isometric, but the six lines pass- 

 ing through their points of contact will be no 

 longer at the constant angles of 60° and 90°, 

 but at varying angles. The angles between 

 the lines in which the molecules are arranged 

 in the mass will correspond strictly with the 

 lines joining the points of contact in each 

 molecule; hence we may limit our thought to 

 a single molecule. 



TABLE OF POSSIBLE DISTORTIONS OF THE EHOIIBIC DODECAHEDRON AND RESULTING 

 CRTSTALLOGEAPHIC SYSTEMS 



