as food for servants. At one time apprentices and servants stipulated that they should not be obliged to feed on salmon more than five days in a week. Salmon was one penny a pound.
“A large boiled salmon would now-a-days have indicated most liberal
housekeeping; but at that period salmon was caught in such plenty
(1679) ... that, instead of being accounted a delicacy, it was
generally applied to feed the servants, who are said sometimes to have
stipulated that they should not be required to eat food so luscious and
surfeiting ... above five times a week.” —
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894