As and aside, there is a "newer" way to develop a daguerrotype plate which does not require Mercury. The plate after exposure is exposed to sunlight behind a red filter ( I think the specific color is very important to the process) and it develops the plate. I can't find the name of the process right now - but I'd think that it would be a load safer if one was interested in Daguerotypes. I had briefly considered it, since modifyling my 8x10 would be pretty easy - but then I saw the cost of copper plate and silver plating.
AgNO3 is quite costly enough, thank you very much. I'll lump that with the Cabon print process when I am retired and have both too much time AND money on my hands (God willing)