From: Judy Seigel (jseigel@panix.com)
Date: 06/30/03-02:00:18 PM Z
On Mon, 30 Jun 2003, Christina Z. Anderson wrote:
> P.S. Ohhh, Sandy; I just thought of a variable I am forgetting, after you
> mentioned below the three at the same strength, and this is why I MUST
> retest it like that: sodium dichromate is thick and syrupy and brilliant
> deep yellow at full strength; is it possible I am getting a faster speed
> read on am di by virtue of sodium's greater density?? When all three are
> painted side by side, pot is a thinner yellow, am is deeper yet, and sodium
> the deepest, and also, I assume, the thickest as it is more viscous than the
> am di solution. Could that really hold back a full stop (and maybe 1 1/2) of
> exposure?
> I need to find my packed Kosar.
So I survived Gay Pride day which brings the revelling hordes to my
doorstep, I survived leak in the shower week, which undid some serious
renovations, I survived daughter moving to LA for the month month, which
brought numerous high bore crises into simultaneous play, and I survived
countless vicissitudes inbetween including the SUDDEN switch from 50
degrees F to 95. It's my finding that the body needs time to adjust --
once the blood thins in the heat, risk of sudden death diminishes. But
back on the list with nearly 100 alt-list e-mails waiting is also dire.
Chris, you weren't testing the 3 dichromates, as you apparently believed.
You were testing the 3 dichromates at their saturated solutions. Which
hardly permits the generalizations you offer.
You cannot assume that qualities you find in, for instance, a 30 %
solution of ammonium dichromate would be the same in a 10% solution of
ammonium dichromate, and so forth. Your generalizations about what is
"faster," "sharper," "contrastier" or "stains" more... can only be
attached to those DILUTIONS, not to those chemicals.
Which essentially was my finding about 5 years ago when i tested all at
the same dilution (& as I recall mentioned several times on this list).
The differences between the dichromates USED AT THE SAME PERCENT SOLUTION
are trivial AND variable. For instance, odds are you'll find as much
variation with a change of size, paper, gum or pigment as from chemical to
chemical AT A GIVEN DILUTION.
I don't think there's any doubt that stronger solutions are stronger.
And hot usually works faster than cold, etc. But for the rest, Q non ED.
As for finding your KOSAR... that's also no use. It WILL NOT deal with the
variables you should be addressing, and if it does, only in the most
remote & general way, full of "probably", "arguably" and "presumably"
conclusions about other people's tests done for other purposes. Which is
exactly why there's so much garbage in this field. People concluding from
undefined irrelevant or mistaken premises.
Sorry,
Judy
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