I entirely agree with G. K. (Vol. viii., p. 269.) respecting the original
sense of "Putting a spoke in one's wheel." It surely meant to aid him in
constructing the wheel, say of his fortune. As the true sense of this
expression seems to have been retained in America when lost in its
birthplace, so Ireland has retained that of another which has changed its
sense here. By "finding a mare's nest" is, I believe, meant, fancying you
have made a great discovery when in fact you have found nothing. I
certainly remember the late Earl Grey using it in that sense in his place
in parliament. But how does this accord with the following place in
Beaumont and Fletcher?
"Why dost thou laugh?
What mare's nest hast thou found?"--_Bonduca_, Act V. Sc. 2.
on which, rather to my surprise, Mr. Dyce has no note. Now in Ireland, when
a person is seen laughing immoderately without any apparent cause, it is
usual to say, "O, he has found a mare's nest, and he's laughing at the
eggs." This perfectly agrees with the above passage from _Bonduca_, and is
doubtless the original sense and original form of the adage.
There is another of these proverbial expressions which, I think, has also
lost its pristine sense. By "Tread on a worm and it will turn" is usually
meant that the very meekest and most helpless persons will, when harshly
used, turn on their persecutors. But the poor worm does, and can do, no
such thing. I therefore think that the adage arose at the time when _worm_
was inclusive of snake and viper, and that what was meant was, that as
those that had the power to avenge themselves when injured would use it, so
people should be cautious how they provoked them. I am confirmed in this
view by the following passage in the _Wallenstein's Tod_ of Schiller, Act
II. Sc. 6.:
"Doch einen Stachel gab Natur dem Wurm,
Dem Willkuer uebermuethig spielend tritt."