From: edzachary (edzachary@my-Deja.com)
Date: 06/27/00-10:32:48 AM Z
Ahh! Please excuse the misunderstanding. I thought we WERE talking about reagent grade. I guess if you're using the homemade stuff, you have to expect a difference.
As for the journals, what I said was "No, I'm not a chemist, but I have read my share of the literature, and I don't ever recall research journals identifying the particular BRAND of chemicals used. ". You know, Jeffrey, photographers aren't the ONLY people using chemicals. These other guys, called "chemists" use them, too. And sometimes they publish their results. Not sure, though, if they specify that the silver that Fischer used for the Silver Nitrate came from Uganda or Idaho.
--On Tue, 27 Jun 2000 11:33:11 Jeffrey D. Mathias wrote: >edzachary wrote: >> ... But its a real stretch when you start to attribute differences >> to BRANDS of chemicals. ... > >Unless the chemicals are manufactured and tested to a certain purity >(such as ACS reagent grade), there can be tremendous differences. The >differences are due to the impurities, whatever they may be. This may >vary batch to batch as well as brand to brand. The certified chemicals >do cost more, but one knows what they are getting. > > >> ... and I don't ever recall research journals identifying the >> particular BRAND of chemicals used. > >Please let us know of ANY research journals writing about alt-photo >processes. I know of only one, the Post Factory Journal (not really a >research journal of the scientific community, but the closest known). > > >> Certainly the difference between Brand A chemical and Brand B chemical, >> if it is so obvious to us, should be observed in the laboratory as well. > >It is! And that is why standard grades are tested and certified. > >> The claim that silver obtained from different mines is somehow a "different" >> silver, well, if that be the case, > >Well then, explain why some find an advantage to using platinum with >trace amounts of iridium or other heavy metals. Modern day platinum has >had all the expensive iridium removed, where as the old timers did not. >Before modern refinement, one could make a case for which mine the >platinum came from (differing amounts and types of impurities). > >-- >Jeffrey D. Mathias >http://home.att.net/~jeffrey.d.mathias/ >
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