Re: haunted VDB
I worked as a lab tech in occupational health and safety in the 1970's and remember that selenium is very toxic. I suggest only working with it in a fume hood while wearing gloves and protective clothing like a lab coat and disposable gloves. Here is a link to a material safety data sheet for selenium: http://www.sciencestuff.com/msds/C2450.html
I'd recommend doing a google search for Material Safety Data Sheets for any element or compound whose of handling you are not certain. Just google: msds (whatever chemical your interested in) and you will get a good number of hits. Some will not have exactly the same info as others for the same chemical. My practice in this case is to err on the side of safety and use the stricter recommendations for handling.
Rodolpho Pajuaba wrote:
If I remember well from my Photographic Formulary book, a selenium toner can be done by mixing the selenium with sodium sulfite (in portuguese, sulfito de sódio, I don't know what it translates right; it's the usual one, so often used in many photographic formulas), in warm water. There is a precipitate that I never managed to get rid of, but I kept it and it never did any harm. Of course I could have filtered it, but I (naively) think that if I did I could nullify the effect ;-) . And yes, it's probably toxic (I'll let the ones that really know say something here), but if you do it in a ventilated environment I think it won't do you no harm.