Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class amines [RNH2, R2NH, R3N]
                 Class catecholamines
                 1 primary amines [RNH2]
                 2 secondary amines [R2NH]
                 3 tertiary amines [R3N]