C for Cumming - A Spunky Idea For A Bond Film
In June 1915 Mansfield Cumming, the first chief (or C) of the SIS was "making enquiries for invisible inks at the London University".....that the best invisible ink is semen", which did not react to the main methods of detection. Furthermore it had the advantage of being readily available.
A member of staff close to "C", Frank Stagg, said that he would never forget his bosses' delight when the Deputy Chief Censor said one day that one of his staff had found out that "semen would not react to iodine vapour".
Stagg noted that "we thought we had solved a great problem".
However, the discovery also led to some further problems, with the agent who had identified the novel use having to be moved from his department after becoming the butt of jokes.
In addition, at least one agent had to be reminded to use only fresh supplies of the 'ink' when correspondents began noticing an unusual smell.
Damned awkward for female spies though, having to spit into an inkwell....