Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class azines [R2C=NN=CR2]
                 1 Class aldazines [RCH=NN=CHR]
                 2 Class ketazines [R2C=NN=CR2]