Salicylaldehyde be prepared from the corresponding phenol by the Duff reaction, or by treatment with paraformaldehyde in the presence of magnesium chloride and a base. Salicylaldehyde was identified as a characteristic aroma component of buckwheat. It is also one of the components of castoreum, the exudate from the castor sacs of the mature North American beaver ("Castor canadensis") and the European beaver ("Castor fiber"), used in perfumery. Furthermore, salicylaldehyde occurs in the larval defensive secretions of several leaf beetle species that belong the subtribe Chrysomelina. An example for a leaf beetle species that produces salicylaldehyde is the red poplar leaf beetle
Castor and Pollux (Prado) Castor and Pollux (Prado) The Castor and Pollux group (also known as the San Ildefonso Group, after San Ildefonso in Segovia, Spain, the location of the palace of La Granja at which it was kept until 1839) is an ancient Roman sculptural group of the 1st century AD, now in the Museo del Prado, Madrid. Drawing on 5th- and 4th-century BC Greek sculptures in the Praxitelean tradition, such as the Apollo Sauroctonos and the "Westmacott Ephebe", and without copying any single known Greek sculpture, it shows two idealised nude youths, both wearing laurel wreaths. The young men lean against each