Mercury Intensifier?

Hey, I've read in a couple of places now about mercury intensification of negatives. It's supposed to boost contrast up to 5 grades and is reversible. I know that mercury is toxic, but how realistic is this process today? Can we even buy mercury?

Here in Europe, mercuric chloride is a class A toxin, what means

that you have to be registered (and argumentate it's use) to obtain

the chemical.

Use potassiumdichromate (not harmless tooo) or selenium.

Nowadays, much trouble can be solved by using VC papers. You cannot

get something out a negative what is not there.

Mercuric chloride is extremely toxic and carcinogenic, and it

accumulates in the environment. Photographer's Formulary does not

stock it. However, it is available from <a

href=http://www.colba.net/~fotochem/index.htm>Fotochem</a> in Quebec.

 

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I have read that mercury is one of the easiest to use intensifiers

and gives excellent results, but these days there are strict federal

regulations on disposal of mercuric waste of any kind.

There is no good reason to use a mercury intensifier. Period. If you

need to intensify to this magnitude then you are exposing and

developing the film incorrectly to begin with. Don't use it. It is an

extreme toxin and should be banned from any but the most needed uses.

It is cumulative in the environment. Don't use it. James