'If you have once exposed the place, then applying the chisel, which has at its point a blunt (rounded), smooth, lentil-shaped knob, but which longitudinally is sharp, when you apply the flat part of the lenticular to the meninges divide the cranium by striking with the small hammer. For we have all that we require in such an operation, for the membrane, even if the operator were half asleep, could not be wounded, being in contact only with the flat part of the lenticular, and if it be adherent anywhere to the calvarium the flat part of the lenticular removes its adhesion without trouble. And behind it follows the incisor or lenticular itself, dividing the skull, so that it is impossible to discover another method of operating more free from danger or more expeditious.' The earliest illustration of the lenticular I have been able to obtain is that given by Vidus Vidius (Pl. XL, fig. 2). It evidently is the same instrument as that described by Galen. _Hammer._ Greek, σφῦρα; Latin, _malleolus_. I have already quoted passages where the hammer is referred to as being used in cranial surgery. Paul says: 'When you apply the flat part of the lenticular to the meninges divide the skull by striking with a small hammer,' and again in using gouges, 'strike gently with hammer (σφῦρα) to avoid concussion of the head' (VII. xc). Paul and Celsus describe a method of extracting foreign bodies from the ear by laying the patient on a board and striking the under side with a mallet. Paré mentions a hammer made of lead, and Fabricius describes one padded with leather, but neither of these is described by the ancients. There is, however, a Roman hammer of lead from the excavation at Uriconium in the Shrewsbury Museum. _Block._ Greek, ἐπίκοπον, a butcher's block. The ancients frequently amputated parts by placing them on a block and striking them with a chisel. The mediaeval surgeons amputated parts as large as the forearm in this way, but the Greeks all describe amputation by knife and saw. We have reference to the 'block' in Greek literature, however. In describing the plastic removal of a portion of the scrotum Paul (VI. lxvii) says: 'Leonidas, laying the patient on his back, cuts off the redundant portion upon a chopping block of any kind of wood or stiff leather' (κατ' ἐπικόπου σανιδίου τινὸς ἢ σκληροῦ δέρματος). Galen uses the same word in the eighth book of his work on Practical Anatomy--apologizing somewhat for calling the article used by anatomists and surgeons by the undignified term of butcher's block: Χρώμενος ἐπικόπῳ, καλέσαι γὰρ οὕτως οὐδὲν χεῖρον ἔστιν ὁμοίως τοῖς ἀνατομικοῖς τε καὶ χειρουργοῖς τὸ στήριγμα τῶν ὑποβεβλημένων τῇ τομῇ τῶν σωμάτων (ii. 685). _Meningophylax._ Greek, μηνιγγοφύλαξ; Latin, _membranae custos_.