sock

Half a sock which has traces for invisible ink and was believed to belong to George Vaux Bacon. Bacon, an American, was recruited into the German Secret Service in New York and was arrested in 1916 while travelling to Britain.

Half of a black sock which has been cut, leaving just the toe end of the sock remaining. The end of the sock is brown with irregular black lines on.

Espionage material taken from German spies arrested in the United Kingdom (left to right): Shirt collars impregnated with invisible ink ; Fragments of sock and bootlaces impregnated with invisible ink ; Pen nib bearing traces of invisible ink ; Cake of soap mixed with invisible ink ; Sponge containing invisible ink ; Pack of cards examined for traces of secret writing ; Harrington and Richardson .32 calibre pistol ; Boot, sock and tie examined for invisible ink ; Pills concealed in a magazine taken from a captured German spy ; Sheet of numbers used as a code by a German spy ; Paper envelope stained with ink.

George Vaux Bacon was an American journalist. He was recruited into The German Secret Service in New York. There, an agent called Davis (real name Charles Winnenberg) applied a think brown liquid to a pair of socks that Bacon had purchased, and said, "There, that is a secret ink which the English will never discover. When you write a letter to Holland with your reports, soak the top of these socks in water and use the fluid as ink." The ink, known as 'P' ink, contained a small concentration of silver proteinate. Bacon travelled from Britain to Holland on around 25 September 1916, where he met more German agents. When he returned to Britain, an agent named Schultz warned him not to take his socks with him, but Bacon took them nonetheless. Shortly after Bacon was arrested in early December 1916, the socks were examined by Britain's foremost secret-ink chemist S.W. Collins. At first the ink defied his attempts to identify it but after using spectroscopic analysis, Collins confirmed the presence of silver. Collins's testimony at the court martial was directly responsible for the sentence of death which was given on 17 March 1917. However, Bacon was returned to the United States where he served a one year prison sentence. This sock is believed to be one of those carried by Bacon for the purpose of making invisible ink.