The Viking Deception (15 of 17)

The Viking Deception

In the middle ages, the most commonly used ink was called iron-gall.
Iron-gall ink was cheap and easy to make.
Galls are growths caused by the larvae of insects in oak trees.
These were crushed to a fine powder and boiled in water to make a solution that looked like tea.
Gum arabic,a kind of glue, was mixed with ferrous sulfate, a mineral containing iron.
The thing that makes ink ink is the reaction between the iron in the ferrous sulfate and the tannin from the oak tree.
These produce a rusting reaction on the page.
The tannin and the iron together are oxidizing on the page and actually burning the letter into the surface.

In fact,the english word "ink" comes from the greek enkaiein, which means "to burn in."
This burning process,over time, causes the iron-gall ink to change color.
The strokes of the pen will leave a grayish mark, and within an hour or two, that will blacken, and within the next year or two, it will blacken completely, but within the next century or two,it will start to go brown.
Many medieval manuscripts have been stained brown by iron-gall corrosion, including the tartar relation and the speculum historiale, the manuscripts that had been bound with the vinland map.
But the ink on the vinland map was not iron-gall.
Mccrone's theory was that a forger tried to simulate the browning effect of iron-gall corrosion by overlaying a black ink on a yellow pigment.
Mccrone says the yellow pigment contains anatase, a modern synthetic, which can only mean the map is a forgery.
Cahill counters that he finds almost no titanium, an essential component of anatase.
He concludes that anatase is not part of the ink, and the map may be real.