Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class cyanides [X+[C≡N]‾, organyl-C≡N]
                 benzoyl cyanide
                 methyl cyanide
                 Class nitriles [RC≡N]
                 sodium cyanide