Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class alcohols [ROH (R≠H)]
                 Class amino alcohols
                 ethanol [C2H6O; CH3CH2OH]
                 Class prenols [H[CH2C(CH3)=CHCH2]nOH; H[isoprene unit]nOH]
                 Class sterols