Chapter XXVII

. he gives instructions for preparing the gum for mixing with colours. This is described as follows: “Take gum which exudes from the cherry or plum tree, and, cutting it up very small, place it in an earthenware pot, and pour water upon it abundantly and place it in the sun, or in winter upon the coals, until the gum has liquefied; and mix it together with a smooth piece of wood. Then strain it through a cloth, and grind the colours with it and lay them on.”

In