He identified them as mallet bottles, which refers to the shape, and explained that, in the decades around 1750 they changed from shorter and squatter to taller and thinner - and we have some of both in the well, as well as some more unusual shapes. Typically, they would have contained French claret.
After 1745, when Bonnie Prince Charlie landed at Glenfinnan, Mingary was occupied by Donald Campbell of Auchindoun, the local factor for the Duke of Argyll. By 1746 the garrison had risen to fifty-nine officers and men who, after Culloden, occupied themselves by harrying the properties of local Jacobite landowners. It seems very possibly therefore that this material belonged to the officers who would have lived in the north range and, apparently, used the well as both a toilet and a rubbish dump.