Prompted by the news of Turing’s “pardun”, here are some facts about the circumstances surrounding his death, from my book Computing with Quantum Cats.
Early in 1952 he had a brief homosexual relationship with a nineteen-year-
old boy who was then involved in a burglary of Turing’s
house in Manchester. Turing reported the burglary to the
police, naively expecting them to help him; when they found
out about the relationship they arrested Turing,22 who was
charged and convicted of the offence that ‘being a male
person [he had] committed an act of gross indecency with . . .
a male person’. His burglarious ‘friend’ was convicted of the
same offence, but seen as Turing’s victim and discharged.
Turing was put on probation, on condition he took a course
of hormone treatment. The court probably thought it was
being lenient, but the ‘treatment’, with the female hormone
oestrogen, made him impotent and fat, and, worst of all,
affected his ability to think clearly and concentrate.
These events are often linked to his untimely death in
1954, officially determined to be suicide. The situation is in
fact rather more complicated than the coroner’s verdict
suggests. At the time of his death the hormone treatment had
been over for a year, and friends describe him as being happy.
Work was going well. He had left a ‘to do’ list for himself at
work before going home for the weekend, and rather than a
suicide note he left behind ready to post a letter accepting an
invitation to a forthcoming event at the Royal Society.
Nothing suggests a suicidal frame of mind. So why the
verdict? Well, he did die of cyanide poisoning, and there was
a partly eaten apple by his bedside, recalling the couplet from
Dip the apple in the brew,
Let the Sleeping Death seep through.
Bizarrely, though, the apple was never tested to see if it
contained cyanide, and Turing had a home laboratory (little
more than a glorified cupboard) where, just as in his childhood,
he dabbled with chemistry experiments. Some of these
involved electroplating using potassium cyanide solution, and
police called to the scene reported a strong smell of cyanide
(the famous ‘bitter almonds’ smell) in the room. A jam jar
containing cyanide solution was standing, uncovered, on the
table in Turing’s ‘lab’. Perhaps significantly, the ability to
smell cyanide diminishes over time, as the concentration of
the gas increases, and the post-mortem examination showed
that Turing’s liver had a low concentration of the poison, not
consistent with its having been swallowed.
The simplest explanation is that Turing accidentally
inhaled a lethal dose of cyanide just before going to bed. At
the other extreme, conspiracy theorists have suggested that as
a homosexual who knew too many secrets he was murdered
on ‘official’ orders. Somewhere in between there is the
coroner’s verdict of suicide. But it is useless to speculate.
What matters is that on the night of 7 June 1954, at the age
of just forty-one, Alan Turing, the founder of modern
computing, died as a result of ingesting cyanide.