Dippel's oil

Dippel's Oil (sometimes known as Bone Oil) is a nitrogenous by-product of the destructive distillation manufacture of bone char. This liquid is dark colored and highly viscous with an unpleasant smell. It is named after its inventor, Johann Conrad Dippel, the oil contains the organic base pyrrol.

Dippel's oil had a number of uses which are now mostly obsolete. These included medicinal uses, use as an alcohol denaturant, as an ingredient in sheep dips, as an animal repellent and as an insecticide.