Bruises

When the contusion is slight, fomentations of warm vinegar and water, frequently applied, will generally relieve it. Cataplasms of fresh cow-dung applied to bruises, occasioned by violent blows or falls, will seldom fail to have a good effect. Nothing however is more certainly efficacious than a porter plaster immediately applied to the part affected. Boil some porter in an earthen vessel over a slow fire till it be well thickened; and when cold spread it on a piece of leather to form the intended plaster.

Source: The Cook And Housekeeper’s Complete and Universal Dictionary, Mary Eaton