Breaking
Turkey's chemical formula and techniques used by intelligence officers of the era to decipher secret correspondence
Turkey's National Intelligence Organization (MIT) has published a historic document from 1933 marked "to be opened personally" in its "Special Collection. The document reveals, for the first time, the chemical formula and techniques used by intelligence officers of the era to decipher secret correspondence."
It describes the method for opening and resealing envelopes and decoding hidden text. The note states: "The letter received from post box 230 and sent to the Presidency for opening was opened using the method described in the note from D Branch. As the first page of this two-page letter was used for testing, some text was lost.
The readable portion and a translation of the second page are attached. As the letter bears the signature 'Lüsi, it is believed the sender may be Lucci Vidman. If chemical treatment is needed for future letters from this box, please use the following formula.
At the bottom of the document, the formula is specified: a mixture of 10 grams of ferric chloride (perchlorür de fer) and 90 grams of distilled water. The note adds: "Place the solution in a tray and bathe the paper as if it were photographic paper. Brushing does not yield good results.
Source: TRT Haber