Eretria takes its name from the territory[1] which produces it. Nicomachus[2] and Parrhasius made use of it. In a medicinal point of view, it is cooling and emollient. In a calcined state, it promotes the cicatrization of wounds, is very useful as a desiccative, and is particularly good for pains in the head, and for the detection of internal suppurations. If the earth, when applied[3] with water, does not dry with rapidity, the presence of purulent matter is apprehended.