Nazi death camp prisoners ‚used urine as invisible ink for letters‘

Letters written in urine written by female Polish prisoners at Ravensbrueck camp
Their ‚Invisible‘ messages appeared when recipients heated up the paper notes
They document horrific treatment at the hands of concentration camp doctors
Shocking experiments included being injected with gangrene to test new drugs

Kommentar von Honestly Concerned
Unvorstellbar... 🙁

Nazi death camp prisoners ‚used urine as invisible ink for letters‘ | Mail Online