From The Ancient Crosses of Lancashire by Henry Taylor:
Mr. Cox writes (in 1888): “The base of the churchyard cross still lies opposite the site of the old south porch.” There is, however, some doubt whether this stone is the base of the cross, or the base of a column of the nave arcade of an older church, but Mr. Cox’s notes, which I give below, are of much interest: “Now, this hollowing at the top of the shaft . . . must have had another purpose. At Derby and many other places, the stump of the cross was so hollowed in order that in time of pestilence money might be placed in vinegar and disinfected before it was exchanged for the goods brought there. The seller left his goods and the buyer his money at the stone, but did not meet, for fear of infection. A stone closely resembling this was found by Dr. Kendrick at Warrington, and is now, I believe, in the museum. Is this old Garston Cross a plague stone? That churchyards were used as markets in the middle ages is a well-established fact.”