This one's for anyone out there involved in the world of publishing who has had to grapple with a slush pile (either from being in it, or having to read it).
Slush is a greasy substance obtained by boiling or scraping the fat from empty salted meat storage barrels, or the scummy fat that floata on top of the kettle when boiling the crew's meal. Yummy. This stuff belonged to the cook, who could sell or exchange it, either to the crew, who would use it to crease parts of the ship's running rigging, or ashore. Money obtained by the cook for his slush was called a slush fund.