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 Oyl prominent appearance in the series is as a member of Popeye's orchestra in the 1935 short "The Spinach Overture". In the 1980 film directed by Robert Altman, Castor is a key character, and is played by actor Donovan Scott. In the film, however, he is made Olive's younger brother and is considerably less sophisticated than his comic strip counterpart. Castor Oyl is named after castor oil, a medicine often given to children for various ailments until the mid 20th century. His mother Nana's name derives from "banana oil," an epithet similar to "baloney." His father Cole's name derives from "coal