Origin of feck?

[SteveB]

In his 1881 short story Thrawn Janet, Robert Louis Stevenson invokes the second sense of feck as cited above:

"He had a feck o' books wi' him—mair than had ever been seen before in a' that presbytery..."
Robert Burns uses the third sense of feck in the final stanza of his 1792 poem "Kellyburn Braes":

I hae been a Devil the feck o' my life,
Hey, and the rue grows bonie wi' thyme;
"But ne'er was in hell till I met wi' a wife,"
And the thyme it is wither'd, and rue is in prime

So has been around since 1792

This a Scottish meaning that is a completely different meaning from the Irish one.
Feck is a Scottish variant of effect, as in personal effects or belongings.