A couple last comments:
(Look. I SAID it was a very narrow point, and that everyone was making
more out of it than they needed to. Now do you finally agree with me
that it is so?)
On Dec 7, 2005, at 5:01 AM, Tom Sobota wrote:
>
> 2. No discussion about the pigment not being involved in the reaction.
> Yes, you contributed
> somewhat to the confusion posting your examples of dichromated gum
> exposed without any
> pigment, but never mind, I now understand the distinction.
How else would you show the distinction?
> Also, those tests were useful to
> see the effect of stain and the several attempts to remove it.
The actual tests there weren't the point; they have to be seen in the
context of a discussion that was going on at the time. The point in
showing them in this discussion was to show that hardened gum in and of
itself doesn't have any color and is different from the color of
stained gum, and that cleared gum isn't the same color as unstained
gum. But the other stuff there, the clearing with salt and sulfite and
whatnot, it wouldn't be accurate to call those "attempts to remove
stain;" those were purely a response to remarks made here about how
salt or sulfite would or wouldn't be as effective in clearing stain as
bisulfite or metabisulfite which are generally considered to be
effective clearers of stain. I disagreed with those remarks and did
the tests to see if the person was right or not, and I have no idea
whether the tests confirmed or disconfirmed the remarks, or some of
each, because I no longer remember the remarks. Obviously there was
nothing in the tests that dissuaded me from using bisulfite or
metabisulfite as a clearing agent. What surprised me was that without
the pigment in the way, you can see that metabisulfite doesn't actually
clear the gum back to clear, it turns it blue.
Katharine
Received on Wed Dec 7 08:54:05 2005
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