Finally found it. I used it, p. 53 of my _History and Practice of Oil and
Bromoil Printing_ I published it so it would be easy for me to find it
later! For the 2 or 3 of you out there who don't have this important book
(yet:-)) here it is:
U.S. Patent 2,860,978, issued in 1958, listed the following preferred
formula for Kodak Hypo Clearing Agent:
In a liter of water, add 0.5 g of sequestrene Na-4 (EDTA), 20 g of sodium
sulfite, and 5 g of sodium bisulfite. The latter decreases the pH to avoid
excessive softening of the emulsion. The EDTA prevents buildup of scale on
equipment when hard water is used; c.f., Pierre Glafkides: _Chimie et
physique photographique_ Paris, Paul Montel, 1976, pp. 186-187; G.I.P.
Stevenson: _J. Phot. Sci._, 1967, pp. 215-219.
BTW, back around 1975 I was helping Ilford develop a paper (that eventually
became known as Galerie), and I showed the above formula to their chemists
who said that theirs was basically the same. It should be noted however
that this formula goes back to 1958 and that someone else has already
mentioned that sodium citrate(?) was listed as one of the current
ingredients.
Luis Nadeau
NADEAUL@NBNET.NB.CA