 The durability of sense in entities and in the air in latent forms—as if asleep, waiting to be reawakened on specific occasions—explains facts that are only apparently miraculous, such as the bleeding of a corpse in the presence of the murder: the victim, if alerted through the air to the proximity of his killer, is again agitated by anger and fear, discharging blood. Also linked to the durability of affects and sense is the efficacy of the weapon salve, attributed to Paracelsus, by means of which a wound can be healed by putting ointment on the weapon that caused it, as if the spiritus enclosed in the wound acquires confidence by feeling the cure via the air and experiences “almost the joy of revenge”. It is also possible to explain a celebrated example found in every book on magic: a drum made of sheep skin falls to pieces when a drum made of wolf skin is sounded, reawakening its former fear (Del senso delle cose, pp. 253–59).