Natura - nature actualia - actual entities Mundus Plinius - physical world naturalia - natural bodies "crystal-kingdom" chemical substances chemical compounds Class hydroximic acids [RkE(=O)l(OH)m (l≠0; ≥1 (=O):=(=NOR))] 1 Class carbohydroximic acids [RC(=NOH)OH] 2 Class sulfonohydroximic acids [RS(=O)(=NOH)OH]