To relieve the heat and irritation occasioned by riding, or any such cause, Rhases directs us to apply a cloth dipped in rose-water properly cooled, he means, perhaps, with ice. After the heat and pain have been removed, an ointment of ceruse, or litharge is to be applied. Blisters produced by walking are to be opened and then washed with rose-water; and afterwards they are to be dressed with an astringent application, containing Armenian bole, galls, pomegranate flowers, or the like. SECT. XV.—FOR MYRMECIA AND ACROCHORDON. Each of these is a small rising of the skin, of a callous nature, and for the most part circular; but the myrmecia have a broad base, and when rubbed, convey a sensation like the bites of ants. But the acrochordon has a narrow base so as to seem to hang, resembling the extremity of a cord. Wherefore, elaterium with salts, when applied, removes these swellings; and frankincense with vinegar, green figs with vinegar, flour and natron, the juice of the fig rubbed in, and in like manner, that of the spurge, the pickled head of picarel burnt, verdigris burnt with sulphur vivum, the leaves of basil with copperas; that which flows from green vine shoots when burning, sheep’s dung with vinegar, a buck-goat’s gall when rubbed in, the fruit of the large sun-flower, when applied with wine, rue with natron and pepper, natron with the urine of a youth not come to puberty, the dung of an ox of the herd in vinegar. * * * * * COMMENTARY. See Celsus (v, 28); Galen (Meth. Med. xiv); Aëtius (xiv, 4); Oribasius (Morb. Curat. iii, 55); Actuarius (Meth. Med. vi, 8); Pollux (Onomast. iv); Avicenna (iv, 3, 1, 6); Rhases (Divis i, 131, _et seq._; ad Mansor. vii, 15, 16.) Celsus defines these tumours in the following terms: “Ἀκροχορδόνα Græci vocant, ubi sub cute coit aliquid durius, et interdum paulo asperius, coloris ejusdem: infra tenue, ad cutem latius: idque modicum est quia raro fabæ magnitudinem excedunt. Vix unum tantum eodem tempore nascitur; sed fere plura, maximeque in pueris; eaque nonnunquam subito desinunt; nonnunquam mediocrem inflammationem excitant; sub quâ etiam in pus convertuntur.” He then describes the θύμιον to be about the size of an Ægyptian bean, and of the colour of thyme. He adds: “Μυρμήκια autem vocantur humiliora thymio durioraque: quæ radices altius exigunt, majoremque dolorem movent: infra lata, supra autem tenuia; minus sanguinis mittunt; magnitudine vix unquam lupini modum excedunt. Nascuntur ea quoque aut in palmis aut in inferioribus partibus pedum.” The acrochordon, he says, if cut out, leaves no roots, and does not grow again. This is not the case with the myrmecia. For it he recommends an application consisting of alum and red arsenic. Galen describes minutely the method of extracting these tumours; but that belongs more properly to the surgical part of this work.