We have already256 spoken of the different kinds of gum; the better sort of each kind will be found the most effective. Gum is bad for the teeth; it tends to make the blood coagulate, and is consequently good for discharges257 of blood from the mouth. It is useful for burns,258 but is bad for diseases of the trachea. It exercises a diuretic effect, and tends to neutralize all acridities, being astringent in other respects. The gum of the bitter-almond tree, which has the most259 astringent properties of them all, is calorific also in its effects. Still, however, the gum of the plum, cherry, and vine is greatly preferred: all which kinds, applied topically, are productive of astringent and desiccative effects, and, used with vinegar, heal lichens upon infants. Taken in must, in doses of four oboli, they are good for inveterate coughs.

It is generally thought that gum, taken in raisin wine, improves the complexion,260 sharpens the appetite, and is good for calculi261 in the bladder. It is particularly useful too for wounds and affections of the eyes.