The Collaborative International Dictionary
halomancy
Alomancy \Al"o*man`cy\, n. [Gr. ?, salt + -mancy: cf. F.
alomancie, halomancie.]
Divination by means of salt. [Spelt also halomancy.]
--Morin.
Wiktionary
halomancy
n. Divination by use of salt. This is the origin for the superstition of spilled salt.