https://www.bbc.com/news/world-asia-49996166
"A Japanese student of ninja history who handed in a blank paper was
given top marks - after her professor realised the essay was written in
invisible ink.
Eimi Haga followed the ninja technique of "aburidashi", spending hours
soaking and crushing soybeans to make the ink.
The words appeared when her professor heated the paper over his gas stove."
Via Jennifer Freeman.
Share and enjoy,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://www.xanadu.com.au/ Chief Scientist, Xanadu
http://www.glasswings.com.au/ Partner, Glass Wings
http://www.sericyb.com.au/ Manager, Serious Cybernetics
