great goo o' his performance; so he sits thinkin' to
himsel': 'This maun be a deil's get, Auld Waughorn himsel' may come to
rock his son's cradle, and play me some foul prank;' so he catches the
bairn by the cuff o' the neck, and whupt him into the fire, bagpipes and
a'!"[79]

In Nithsdale the elf-child displays a superhuman power of work. The
mother left it on one occasion in the charge of a servant-girl, who sat
bemoaning herself. "Wer't nae for thy girning face I would knock the
big, winnow the corn, and grun the meal!" "Lowse the cradle band," cried
the child, "and tent the neighbours, an' I'll work yere wark." With that
he started up, the wind arose, the corn was winnowed, the outlyers were
foddered, the hand-mill moved around as by instinct, and the knocking
mell did its work with amazing rapidity. The lass and the elf meanwhile
took their ease, until, on the mistress's return, he was restored to the
cradle and began to yell anew.[80]

Most of the stories of changelings, in fact, assume that, though the
outward characteristics might justify vehement suspicion, yet they were
not absolutely decisive, and that to arrive at certainty the elf must be
brought to betray himself. No great subtlety, however, was needful; for
the stratagem employed varies but little, as the following examples will
show. The child of a married couple in Mecklenburg at two years of age
was no longer than a shoe, but had a mighty big head, and, withal, was
unable to learn to speak. Its parents were led by an old man to suspect
that it had been changed, and their adviser told them: "If you wish to
become certain, take an empty egg-shell, and in the child's presence
pour in new beer and cause it to ferment by means of yeast. If then the
child speak, my conjecture is right." His counsel was followed, and
scarcely had the beer fermented when the child cried out from the
cradle:

"I am as old
As Bohemian gold,
Yet for the first time now I see
Beer in an egg-shell brew'd to be."

The parents determined to fling the babe into the river the following
night; but when at midnight they rose for the purpose they found in the
cradle a strong, blooming child. In a Welsh tale from Radnorshire the
egg-shell is boiled full of pottage in the children's sight (there are
twins in this case) and taken out as a dinner for the reapers who
happened to be cutting the rye and oats. In Glamorganshire the woman
declares she is mixing a pasty for th