I went to the library to pick up Brambly Hedge and never got past the entry. There was a book sale: 50 cents an inch! Oh the raptures of a library sale! It was torture trying to confine my purchase to the 3 dollars in my purse.
I found Poets of the English Language (1950) Langland to Spencer, Studies in Grammar (1924), Old English Handbook (1935), and The Best Behavior--The course of good manners from antiquity to the present (1970).
This last book explained in the introduction why it is good manners to break your bread rather than bite into it.
Boke of Curtasye (c.1340) Bite not thy bread and lay it down, This is not
curtesy to use in town; But break as much as you will eat, The remnant to
the poor you shall lete (leave).