Woman of the Week – Mabel Elliot

Mabel Beatrice Elliot, who often went under the pseudonym Maud Phillips, saw what most couldn’t. Her discoveries helped interpret messages from German spies in World War I.

Not much is known about her early life. In fact, she was only credited with her discoveries in 2011. She was working as a deputy assistant censor for the British War Office and spent her days inspecting all the letters that came through.

One day in 1915, she came across an envelope she found suspicious. On the outside, it was a regular business letter, but she noticed invisible words had been added among the correspondence. The letter was written by a man residing in Liverpool, originally from New York City, who was writing to a friend in Holland.

Source: Royal Chemistry Society

She applied heat to the letter, causing the “invisible” words to appear which had been written in invisible ink. Those invisible words provided secret messages concerning dispositions of Royal Navy ships around the coast, as well as the deployment of forces defending London. It was found to be written by a German spy, Anton Kuepferle, a naturalized American.

The discovery led to his trial, which he didn’t see through, as he killed himself before it concluded. Before his death, he admitted to being a spy, which lead Elliot to make further secret message discoveries in the letters of two other German spies. Those men were convicted.

It’s said that the secret words were written in lemon juice. When heated, the sugars in the lemon juice react with the oxygen in the air and turn the words dark brown. Other ways, like painting over the acidic letters with a pH inhibitor will also show the writing, in that case the ink would turn pink because of a reaction between a pigment in the cabbage called flavin and the acid in the lemon juice, according to Lesley Yellowlees of the Royal Society of Chemistry.

Elliot was a member of the Royal Chemistry Society, but she mostly operated under her pseudonym. She was not credited with the discovery until 2011, when an RSC representative found out more about her.

She did earn some honor though: in 1937, the RSC conferred an honorary membership upon her and it was the first ever given to a woman.

She helped the efforts of the second World War as well. She served as an interpreter and escorted women away from internment camps. She also passed her Red Cross exams to help nurse people and eventually became Commandant of the 78th Middlesex Detachment.

She died in 1944, and an RSC obituary noted this about her life: “She would not let herself be cast down by troubles that would have made many despond. Even when it came to the last great trial, she faced an operation and a painful lingering illness, which she knew would probably prove fatal, with the same unflinching spirit that she had shown towards the German blitz.

"A favourite quotation of hers was Hugh Walpole's 'It isn't life that matters! It's the courage we bring to it.'"