Which preposition to use with unturned

in Occurrences 4%

" After parting with the minister, Mr. Thomas resolved, if pluck and energy were of any avail, that he would leave no stone unturned in seeking employment.

against Occurrences 1%

There would be no fear except that it might be made a party case, and no stone was likely to be left unturned against a gentleman of good loyal family.

Which preposition to use with  unturned