The phrase δι' ἐκκοπέων ἀντιθέτων, which Paul uses in describing the treatment of a fistula leading to carious bone, is translated by Briau--'à l'aide de tenailles tranchantes'. It does seem here, and occasionally in other passages, as if the phrase might suggest 'cutting forceps', but we have no knowledge of such an instrument being used by surgeons in classical times, and the passages from Paul and Galen show that only two chisels are meant. We may compare the passage on extraction of the foetus in Paul (VI. lxxiv), where he directs a second hook to be fixed on opposite the first (καὶ ἀντίθετον τούτῳ δεύτερον). _Gouge._ Greek, κυκλίσκος, κοιλισκωτὸς ἐκκοπεύς, κυκλισκωτὸς ἐκκοπεύς, σκυλισκωτὸς ἐκκοπεύς; Latin, _scalper excisorius_. The Greek writers frequently refer to the gouge. Celsus never does so by any special name, although it is evident that many of the manipulations he describes as being performed by the 'scalper', his general term for chisels of all kinds, could only be performed with gouges and not with flat chisels. The gouge was a favourite instrument of Galen's, especially in injury to the skull. With it he removed pieces of fractured bone from the skull. He also used it to groove a path for the vertical cutting instrument called the lenticular (q. v.). He calls it a 'hollow chisel' (τῶν κοίλων ἐκκοπέων οὓς καὶ κυκλίσκους ὀνομάζουσιν, x. 445). Paul (VI. xc) says: 'And if the bone be weak, naturally, or from the fracture, we cut it out with gouges (σκυλισκωτοῖς), beginning first with the broader ones, and changing to the narrower, and then using those which are probe-like, striking gently with the mallet to prevent concussion of the head.' The gouge is still familiar to us. _Lenticular._ Greek, φακωτός. The lenticular of the ancients was a vertical chisel cutting on one edge and struck on the other by a hammer, while the end carried a rounded button, which being smooth did not injure the brain (Pl. XL, fig. 4). It takes its name from the lentil-like (φακωτός) shape of the button. Galen had a high appreciation of it, and gives a full description of its principle (x. 445), which is transcribed by Paul (VI. xc): 'The method of operating with a sort of incisor called lenticular is greatly praised by Galen, being performed without drilling after the part has been grooved all round with gouges.' Wherefore he says: