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
                   Class sphingoids
                     sphinganine [C18H39NO2; HOCH2CH(NH2)CH(OH)[CH2]14CH3]