1) The gallon could be a dry measure for corn, bread, and the like but it was more commonly a vessel for holding liquids.
1519 Item that the brewsters sell a gallon of her best hale for jd ob the gallon, Selby. It was listed in inventories along with churns and tubs: 1575 ij wodd gallons, iiijd, West Burton
1598 One greate skeile One little gallon, Knaresborough
1698 2 gallons & a piggon, 2s
1 flascitt, Salterforth. In Grassington, in 1675, a constable who was searching for a stolen sheep reported that he had found mutton salted in a kitt or gallon in the house of Robert Smith. This was probably a wooden vessel, but the examples quoted in the OED are evidence that gallons used on more important occasions had ‘gilt verges’ or were ‘half gylte’: in 1443 a Nottinghamshire gentleman possessed a galonpott of silver that weighed more than four pounds.