1838. The qualities and durability of pots and saucers depend on the sort of clay and degree of burning, in which a knowledge can only be acquired by observation and experience. Pots too much burned crack and fall in pieces; and those which are not burned enough splinter or scale off with the frost and continued moisture. Porous earthenware is most congenial to the plants; but, by admitting transpiration by the sides, dries the earth within sooner. Pots made of washed clay are less porous than those of common earthenware, and, having the advantage of being more easily moulded, they are consequently more beautiful in their forms, and more exact in their proportions. Glazed or stoneware pots are not congenial to plants, but they retain moisture a long time.