Quote Originally Posted by sanking

Daguerreotypes are made on a silver plated copper plate. The silver plating is made light sensitive by fuming with iodide and then bromine. After final fuming the plate is placed in a light sensitive holder and exposed in the camera. After exposure, the plate is developed in a fuming hood by heating mercury.

Someone has to be really nuts to mess with mercury vapor (methyl-mercury) which is highly neurotoxic, poisonous and if it gets in your system, it'll never get out... Do a google search on "mercury intoxication" and you'll see...