[De epidemia et peste]

lest they help the poisonous vapor to go to the heart. Nor unctuous [substances], like lard and the like, at least in the beginning, because they would close the pores. Therefore, those who place rose oil, vinegar, oil of unripe olives, bolus armenicus, and the like on top are mistaken. However, for the sake of defense, they can be placed between the region of the heart and the abscess so that they close the pores and do not permit the poisonous vapors to come to the heart. Sixthly, let such a plaster be made according to Avicenna. Take: one handful of fresh maidenhair fern, orache, bindweed, and root of butcher's broom; let them be boiled in water and wine by half until consumption; let them be crushed strongly and add enough honey. Let a plaster be made by adding one ounce of powdered pine gum. Another plaster: Take two ounces of fat figs and cleaned raisins, three drams of saltpeter, one ounce of honey, enough oil of chamomile. Let a plaster be made. Another plaster: Take sour leaven and let it be crushed strongly and incorporated with scabious juice. Another: Take an egg yolk and incorporate it with scabious juice and salt. These plasters should be made for an abscess that does not break in the beginning, such as an anthrax. Here it is to be noted that the wish of Avicenna, and my advice, is that the abscess be pierced before it becomes living in its poisonousness. Therefore, he wants it to be opened on the fourth day with a razor or a phlebotomy lancet. I, however, have sometimes caused these abscesses to be opened and nothing came out except a little blood. In the second visit, poison came out; later, pus. Therefore, let not perfect maturation be awaited, but let it be pierced quickly. And for precaution, let a maturing plaster be placed on top, and partially a cleansing one. Some, however, extract the abscess entirely by taking it with forceps and cutting it, which I do not approve because of the great pain caused there, by which strength is prostrated. Secondly, because of the excessive flow of blood, therefore