Quote Originally Posted by clayne View Post
Amusingly I was recently thinking about this lately (who knows why) - but based on some earlier discussion in this thread, can one use urine as a developer for silver-based films or is it just a non-possibility due to the lack of developing agents?
The latter, I think, for most of us. But there's a disorder called alkaptonuria that causes a developing agent related to hydroquinone to be excreted in the urine: see http://www.cmaj.ca/cgi/content/full/172/8/1002, a case study that includes a portrait of the patient developed in his urine.

-NT