Odd this day

3 min readApr 1, 2023

Ooh, it’s 1 April, which can only mean one thing. YES, THAT’S RIGHT! It’s the 164th anniversary of the birth of Sir Mansfield George Smith-Cumming, first head (or ‘C’) of the Secret Intelligence Service, and the man who once announced:

the best invisible ink is semen.

Incredibly, despite the date, and him having that surname, this is entirely true. The story pops up in Keith Jeffery’s MI6, The History of the Secret Intelligence Service 1909–1949.

Keith Jeffery’s book MI6, The History of the Secret Intelligence Service 1909–1949, lying on a shelf in front of a lot of other books. It’s a large, red tome

Apparently, C told Walter Kirke, deputy head of military intelligence at GHQ France, the joyful news in October 1915, having been looking for some time for a secret ink

from a natural source of supply.

We don’t know who exactly made the fateful discovery, but after months of investigation, one of Deputy Chief Censor F. V. Worthington’s staff found that — while one could write invisibly in semen — it didn’t react to iodine vapour, the traditional way of revealing secret messages.

We don’t know the sequence of events that led them to test this particular substance, but Worthington

had to remove the discoverer from the office immediately as his colleagues were making life intolerable by accusations of masturbation.

Frank Stagg, who worked for C, wrote: “We thought we had solved a great problem”, but there were difficulties:

our man in Copenhagen evidently stocked it in a bottle — for his letters stank to high heaven and we had to tell him a fresh operation was necessary for each letter.

Yes, this is entirely disgusting. Sorry. Still, on a happier note, the history of spying also tells us that that bit in Goldfinger where Sean Connery takes off a wetsuit to reveal a dinner jacket underneath is based on a real life incident…

Sean Connery as James Bond in Goldfinger, removing a diving suit to reveal a perfectly pressed ivory dinner jacket underneath

According to the Times:

In summer 1940 SIS slipped agents into the Netherlands, including one in full evening dress under a rubber oversuit to keep him dry while landing, so that he could ‘mingle with the crowd on the front’

…and this paragraph is pretty unimprovable, too:

Even more unusual attire was worn by Lieutenant-Colonel Dudley Wrangel Clarke, whose behaviour threatened to disturb SIS’s position in Spain. Using cover as a war correspondent for The Times (he wasn’t) Clarke was arrested in Madrid “dressed, down to a brassière, as a woman”. He said that he was taking the clothes to a lady in Gibraltar and tried them on for a prank. “This,” added the British Embassy in a report to London, “hardly squares with the fact that the garments and shoes fitted him.” He returned to Cairo and went on to have a brilliant career in deception.




Purveyor of niche drivel; marker of odd anniversaries