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) other, and to their left on an altar is a small female figure, usually interpreted as a statue of a female divinity. She holds a sphere, variously interpreted as an egg or pomegranate. The group is 161 cm high and is now accepted as portraying Castor and Pollux. The lefthand figure was originally headless but was restored in the 17th century, the heyday of interpretive restorations, by Ippolito Buzzi, when the sculpture was in the collection of Cardinal Ludovico Ludovisi, using a Hadrianic-era (ca. 130) bust of Antinous of the Apollo-Antinous type from another statue. The identification of the figures