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At 04:00 PM 12/10/2009, David Bradbury wrote:
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James Enterline wrote:
At 04:50 PM 12/9/2009, David Bradbury wrote:
Assuming that the McCrone and Brown/Clark analyses did not
mysteriously select freakishly anomalous sampling locations, I'd
have to ask why, despite the wide variety of analytical techniques
used, there have been no reports of the significant quantities of
tannic acid you would expect to find in the Vinland Map ink if Jim
Enterline's theory is correct.
The answer may simply be that nobody has done a determinative test
for tannic acid.
Both FTIR and Raman spectroscopy, which have been used on the
Vinland Map ink, are theoretically able to do the job, but neither
of the analysts responsible reported relevant peaks.
This may be simply because neither were looking for such peaks. This
is the whole reason I keep saying that someone should do my
experiment with a more open mind. Farther on this right below.
Ever since the McCrones announced that the binder looked like early
titanium paint, everyone has assumed that it is.
That's slightly unfair. In 1974 they merely announced that the ink
contained a high concentration of anatase particles in an unknown
organic binder. Although they speculated that it seemed similar to
alkyd resin, which is indeed a 20th century paint binder, it was not
until Walter McCrone applied FTIR in the 1990s that he was able to
make a fairly confident statement, namely that the binder appeared
to be based on gelatin made from skin.
Indeed, McCrone's confidence in that statement seems more justified
by spectroscopy than some other grandstanding of his. However, his
allusion to it as "the binder" is an assumption for which Olin
provides an alternative, that ii results from hydrolysis of the
parchment collagen in situ. Furthermore it is still not determinative
between tannin and gelatin for the following reason: His published
spectrum (Fig. 3 in his 1999 paper) is cut off at the left just
before one would expect the peaks (dips) for tannin at 0.254 and
0.280 microns. It would be interesting to know if his unpublished
raw data includes any points in that neighboring region. The Brown &
Clark graph has a corresponding vacuum at its right edge where tannin
might appear.
...
The problem for Jacqueline Olin's theory is the genuinely freakish
ratio of titanium to iron (resulting from both a surplus of
titanium and a shortage of iron, relative to known iron gall inks)
in the Vinland Map ink in situ.
The relative shortage of iron is obviously explained by the
Enterline scenario. And the surplus of titanium is explainable by
my (or other) transfer scenarios
No it isn't. There's too much titanium underneath the surviving
parts of the black layer of the ink.
Who's to say how much is too much? The bleaching / transfer I
suggested would leave the temporarily re-fluidized ink vulnerable to
lateral transfer of anatase under any black film from mechanical
action of the applying brush (as well as diffusion). Furthermore,
this episode could introduce a new plausibility for Olin's
and Cahill's ink-separation hypothesis. Carbon in the original ink,
now fluidized in an alkaline environment, might ball up toward the
center of the line. The rare examples of mis-registration of the
black layer could have been caused by shear forces when the bleach
brush swept a bubble aside. When everything dries out, any anatase
deposited on the plain parchment could fall off and the carbon could
begin flaking away.
In any case, McCrone's tale of a forger sitting down and painfully
retracing, almost perfectly, a map he had just painfully fabricated
is too much to swallow. It is too circular in motivation. The
conclusion of forgery surely came before the hypothesis of
retracing. And even before he could have lifted a pen, the forger
had to sit down and dope out the Latin cryptograms he was going to
incorporate into the inscriptions, an art not practiced since the
middle ages. And to what end nowadays?
Jim Enterline
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