Beaver extinction in part for the production of castoreum, which was used as an analgesic, anti-inflammatory, and antipyretic. Castoreum was described in the 1911 British Pharmaceutical Codex for use in dysmenorrhea and hysterical conditions (i.e. pertaining to the womb), for raising blood pressure and increasing cardiac output. The activity of castoreum has been credited to the accumulation of salicin from willow trees in the beaver's diet, which is transformed to salicylic acid and has an action very similar to aspirin. Castoreum continues to be used in perfume production. Castoreum can be used as an enhancer of vanilla, strawberry and raspberry flavorings.
Perfume used as middle notes. Manufacturers who publish perfume notes typically do so with the fragrance components presented as a "fragrance pyramid", using imaginative and abstract terms for the components listed. Grouping perfumes can never be a completely objective or final process. Many fragrances contain aspects of different families. Even a perfume designated as "single flower", however subtle, will have undertones of other aromatics. "True" unitary scents can rarely be found in perfumes as it requires the perfume to exist only as a singular aromatic material. Classification by olfactive family is a starting point for a description of a perfume, but