Changes in Color of Hair and Feathers

In the late 19th century, pilocarpin was studied for its potential to induce hair growth and change hair color. One individual with general baldness saw complete hair regrowth after twenty pilocarpin injections, but others did not respond, and Landesberg of Philadelphia reported no hair growth effects in over a hundred eye-disease patients treated with pilocarpin. Experiments on rabbits by Julius Pohlman in 1882 showed that pilocarpin injections could deepen and spread a brown spot on party-colored rabbits, but had no effect on pure white rabbits, and some rabbits experienced enlarged spleens and altered suprarenal capsules post-mortem. Additionally, a fatal case of mussel poisoning in Dublin was linked to a leucomaine that might be the same as Brieger's mytilotoxine.