A form of divination practiced with a sieve and a pair of
tongs or shears, which are supported on the thumbnails (or the
nails of the middle fingers) of two persons facing each other.
In his book Archaeologia Graeca; or the Antiquities of Greece
(169799), Bishop John Potter writes
It was generally used to discover thieves, or others suspected
of any crime, in this manner they tied a thread to the
sieve by which it was upheld, or else placed a pair of shears,
which they held up by two fingers, then prayed to the gods to
direct and assist them; after that they repeated the names of the
persons under suspicion, and he, at whose name the sieve
whirled round or moved, was thought guilty.
In the Athenian Oracle it is called the trick of the sieve and
scissors, the cosciomancy of the ancients, as old as Theocritus,
the writer having mentioned in his third idyll a woman who was
very skillful in it. Richard Saunders, in his Physiognomie and Chiromancy
(1653), and Agrippa gives certain mystic words to be
pronounced before the sieve will turn.
Coscinomancy was also used to discover love secrets as well
as to identify unknown persons.