Whistling
It is considered unlucky for sailors to whistle aboard ship. This is of the nature of sympathetic magic, as it might possibly raise a whistling wind.
White Daughter of the Philosophers: (See Philosopher's Stone.)
From Abracadabra to the Zohar: the classic 1920 reference to every occult science, seance trick, demon, alchemist and secret society — 2,000+ entries, all here.
It is considered unlucky for sailors to whistle aboard ship. This is of the nature of sympathetic magic, as it might possibly raise a whistling wind.
White Daughter of the Philosophers: (See Philosopher's Stone.)