Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             reactive intermediates
               Class anions [X‾]
                 1 acetate [[CH3COO]‾]
                 2.1 nitrate [[NO3]‾]
                 2.2 nitrite [[NO2]‾]
                 2.3 Class aminoxides [R2NO‾]
                 3 sulfate [[SO4]2‾]