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
Cybernetics: Or Control and Communication in the Animal and the Machine derived from Maltz's work. "Cybernetics" became a surprise bestseller and was widely read beyond the technical audience that Wiener had expected. In response he wrote "The Human Use of Human Beings" in which he further explored the social and psychological implications in a format more suited to the non-technical reader. In 1954, Marie Neurath produced a children's book "Machines which seem to Think" , which introduced the concepts of "Cybernetics", control systems and negative feedback in an accessible format. Cybernetics: Or Control and Communication in the Animal and the Machine Cybernetics: Or Control and Communication in the Animal and the