The third kind is still worse. For it is both thicker and harder, and more swelled; it causes fissures in the surface of the skin, and corrodes more vehemently. This also is scaly, but black; it spreads wide(91), and does not stay long at a time; but is less uncertain as to its periods of coming and going; and is not to be entirely removed. This has the epithet of the black. There is a fourth kind absolutely incurable, very different from the rest in colour. For it is whitish, and resembling a recent cicatrix; it has scales of a pale colour, some whitish, others resembling a lentil; which being taken off, blood sometimes follows. Otherwise the humour of it is white, the skin is hard and chopped, and it spreads wider. All these kinds happen chiefly in the feet and hands; and they also infest the nails. There is no medicine more efficacious than that I mentioned for the scabies, which bears the name of Protarchus. Serapion made use of the following composition, nitre p. ii. *. sulphur p. iv. *. incorporated with plenty of resin. [Sidenote: _Of the papula._] There are two species of the papula. One is, where the skin is made rough by very small pustules, and is both red, and gently corroded; in the midst of them is a space somewhat smoother; it spreads slowly. And this disorder is of a round form in its beginning, and proceeds in the same manner circularly. The second, the Greeks call agria: which has a similar appearance, but the skin is more unequal and ulcerated, and it corrodes more vehemently, is redder, and sometimes also loosens the hairs. That which is less round, heals with greater difficulty; and unless it be cured, it turns to an impetigo. But a slight papula, if it be rubbed every day with fasting spittle, will heal. The greater kind is very well cured by feverfew rubbed over it. But for the compound medicines, that same prescription abovementioned of Protarchus is so much the more powerful here, as the distemper is less. There is another of Mico’s for the same purpose; of red nitre, frankincense, each p. i. *. cantharides cleansed p. ii. *. crude sulphur a like quantity, liquid turpentine resin p. xx. *. meal of darnel three sextantes, three cyathi of git, and one sextans of crude pitch. [Sidenote: _Of the vitiligo._]