This is why accurate citations are important:
I decided I should go back and read the Eder paper for myself, Eder
1878, and see the famous paragraph in context. So I looked in Kosar for
the reference, and found British Journal of Photography, 25: 150-151. I
put in the order at the library and waited three weeks and yesterday in
my mailbox I got the article. But wait! The famous paragraph is not in
these pages, and at the bottom there is a note: To Be Continued.
So does anyone have the reference to the continuation of the article?
BTW, If anyone in my class had made a sloppy citation like this, that
person would have flunked too, just like anyone who wrote a bad
abstract. Off with their heads! ;-) Yes, I know I sound like an
impossible old battleaxe, but just the same it's a fact that I got
standing ovations at the end of the term more than once. And I know that
there are people out there writing better research reports, and having
the ability to read and evaluate research reports with a critical mind,
because of me. So think what you like.
But back to Eder: The article that I got says almost nothing about
dichromated colloids, but what it does say is interesting:
"The second group of photographic processes in which chromates are used
is of far greater importance [the first group, that took up most of the
article, was pictures made only of irradiated dichromate]. These are
based upon the property of chromates of rendering certain organic
substances insoluble through the action of light, or of wholly
transforming them, so that it is no longer the chromous oxide [obviously
this was a mistaken idea, as it's pretty clear by now that if there is
an oxide involved, it's not chromous but chromic oxide, probably Cr2O3]
but the organic substance changed by the light, that forms the image.
"We have now to find out in what way the action of the chromates
proceeds, of what the organic substances changed by the light consist,
and how far the chromous oxide produced contributes to the formation of
the photographic image. The prevailing idea, which can be traced back to
Swan, is that the picture-producing organic substance contains chromous
oxide as an integral component, and that the picture is first produced
by the chromous oxide in a secondary reaction. Whether this view, which
is supported by some experiments of Swan's, be correct, or whether the
other idea -- that the chromate light picture is formed by the oxidised
organic substances, as is pronounced by Lemling and Liesgang to be the
case, was not decided and upon the basis of existing observations cannot
be stated with certainty."
Seems to me we're not a lot farther toward sorting that out now than
Eder was in 1878.
Received on Fri May 14 09:07:28 2004
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