castoreum

The bitter exudate of the castor sacs of mature beavers, used as a scent mark, and as a tincture in some perfumes.

One of the substances tried was castoreum.[…]If I were to judge from my own experience, I would say castoreum has very little therapeutic power, for I have not seen much benefit from its employment in those cases to which this remedy is said to be adapted.

While the role of castoreum as a means of territorial advertisement has been extensively investigated and supported, the possibility of coding for sex information has not yet been excluded.

A hat made from beaver fur.