.
.
...
9a
What
happens to black felt pen colours in paper?
(
Makrochemie: Chemie heute S1, 2001, S.15)
In experiment
7 a black line of a felt pen was drawn to the lower part of a wick.
The line was separated into different colours by methylated spirit climbing
up the wick.
In
the following experiment you will draw circles on filter papers to be placed
on the top of wicks.
As
Stabilo is water-soluble you can also replace methylated spirit by water.
Material:
Black
felt pens (Edding, Pentel, Stabilo, Rotring). Micro burner inside infusion
bottles 50 mL, 5 small round filter papers, pencil, coin.
Experiments:
1. Draw circles on filter
papers with different black felt pens using a coin.
2. Use a pencil to write
the type of pen on the backside of the paper.
Left: 3. Draw a half
circle using a Stabilo pen. Complete the name "Stabilo" by a pencil
4. Pull the wicks out of
each Liquemin bottle as much as needed to touch the filters placed on the
infusion bottles around them.
5. Place the filter papers
on the wicks: Starting from their centers liquid will spread in the papers.
Observation?
Explanation? A detctive could use
this method to convict a forger?
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modificationg: 31.10.2002