U of S | Mailing List Archive | alt-photo-process-l | Re: white precipitate in VDB

Re: white precipitate in VDB

Silver nitrate should be dissolved in deionized or triple
distilled or some high grade pure water if precipitation of
silver chloride, etc., is to be avoided. In silver gelatin
emulsion making, this is essential. (The other extreme would
be the silver to be added to "hypo alum toner", in which case
it doesn't matter at all.)

Bottled water you buy from grocery stores typically have a few
counts of bacteria (such as E coli) per liter. Most municipal
tap water (at least in Cambridge, Massachusetts, anyway)
bacterial count is usually zero per liter. Not that a few
counts of E. coli in water is more dangerous than biting your
nail, or having a lunch at an office desk, but the question is
whether the grocery stores should be selling scientific lab
quality water that won't taste good and may contain more
bacteria... or something that's purer than tap water but not
quite lab quality water.

Ryuji Suzuki
"Make something religious and people don't have to deal with it, they
can say it's irrelevant." (Bob Dylan, Biograph booklet, 1985)