Re: clearing dichromate stain
Could someone send me a two sentence summary? hehehehe Best Wishes, Mark Nelson Precision Digital Negatives - The System PDNPrint Forum at Yahoo Groups www.MarkINelsonPhoto.com In a message dated 1/9/07 3:50:19 PM, kthayer@pacifier.com writes: On Jan 8, 2007, at 10:02 AM, Ender100@aol.com wrote: > I would think a review of the historical literature would be quite > interesting regardless of the fact that there might be inaccurate > statements. Documentation of the changes in "accepted practice" > over the years would be quite valuable, along with what caused > those changes, especially if it included an evaluation of what > turned out to be fact or myth. Chris should be applauded for > taking on such a project! Yes, it's a very good thing to try to separate fact from myth; that's been my sole project in the now nearly nine years I've been contributing to this list. And I would applaud Chris's effort, if I could see that there actually were a critical evaluation based on science and fact which clearly separates myth from fact. However, this doesn't seem to be the case; in this case misinformation from the past is continuing to be propagated on into the next century rather than weighed and corrected. Just for one rather trivial example, the statement that's attributed to Sil Horowitz, that in dichromate stain, the dichromate is "fully oxidized" and therefore inert. If Sil Horowitz said that, he's an idiot, but I'm completely comfortable saying that, because I don't think he is an idiot, I think it's much more reasonable to assume he was misquoted. The only way the first part could make sense is if he meant the yellow stain where the unreduced dichromate is trapped in the paper or the size, but in that case the second part wouldn't make sense; such a stain couldn't be considered inert. Anyone with any knowledge of the chemistry of the process would know that it's a nonsense statement as given, and would either check with Horowitz to find out what he really said, or at least drop the secondhand citation from the listing, since it's obviously a misstatement of fact. In any case, a he-said citation isn't acceptable from a scholarly standpoint; I never would have accepted such a citation in papers written for my classes. One should either get the information from the original source, or leave it out entirely, because when the original source is interpreted by a second source, there's no assurance that the second source isn't misinterpreting the information, as may have happened in this case. And of course the assertion most recently under discussion, that because potassium metabisulfite is more soluble, it washes out of paper faster than potassium or sodium bisulfite, is another example of misinformation that's simply repeated from the historical record as fact. I don't even want to do this, but I feel a responsibility when misstatements are made about the gum process, to correct those misstatements. I'm not picking on anyone particularly; I will challenge misstatements wherever they come from, and would hope for a collegial discussion to resolve the issue. That's the kind of atmosphere I come from, where it's considered rude not to correct a colleague when they're saying something wrong. I would certainly hope to be corrected if I make misstatements, and have been corrected here, and am grateful for the correction. This is how we grow as a group, this is how the knowledge of our process advances. Katharine |