in the glas trade, a name for a fine milk-white glass. There are several ways of making it, but the best of all is this: take 400 weight of crystal frit, 60 pounds of calcined tin, and two pounds and a half of prepared manganese; mix these well with the frit, and let them in a pot in a furnace melt and refine. At the end of 18 hours this will be purified; then cast it into water, purify it again afterwards in the furnace, and make a proof of it. If it be too clear, add 15 pounds more of calcined tin; mix it well with the metal, and let it stand one day to purify; it will then be of a whiteness surpassing even that of snow, and is fit to work into vessels.