A special instrument for perforating the foetal cranium is mentioned by Soranus (II. viii. p. 366):
Εἰ δὲ μείζονος τοῦ κεφαλίου ὑπάρχοντος ἡ σφήνωσις ἀποτελοῖτο, διὰ τοῦ ἐμβρυοτόμου ἢ τοῦ πολυπικοῦ σπαθίου κρυπτομένου μεταξὺ λιχανοῦ καὶ τοῦ μακροῦ δακτύλου κατὰ τὴν ἔνθεσιν.
‘If the head be too big, the obstruction may be removed by the embryotome, or the polypus knife, concealed between the index finger and the thumb during its introduction.’
The other authors who recommend this unpleasant operation use mostly the polypus-scalpel or the phlebotome, and hence we may conjecture that a straight two-edged blade was considered the most suitable. The embryotome figured by Albucasis is of this shape ([Pl. VIII, fig. 7]), as is also the cutting part of the perforators of more modern times—fortunately now obsolete.
Probe pointed blade with two cutting edges.
There is in the Orfila Museum, Paris, a fine little two-edged bistoury of bronze with a probe point ([Pl. VIII, fig. 2]). It is a relic of the Roman occupation of Egypt. Its use must remain a matter of conjecture as we have no written description of such an instrument. It is perhaps a fistula knife.
II A. (a) Curved bistoury—‘Crow Bill.’
Greek, ὀξυκόρακον σμίλιον.
In extirpating warts Paul (VI. lxxxvii) says we put them on the stretch with a vulsella and extirpate them radically with a scalpel shaped like a crow’s beak or a phlebotome (ὀξυκοράκῳ σμιλίῳ ἢ φλεβοτόμῳ ἐκ ιζῶν ἐξελεῖν). This undoubtedly refers to a curved scalpel, for the grappling hook was called κόραξ.
In Celsus the instrument appears under the term corvus. In describing the opening of the scrotal sac in the operation for the radical cure of hernia he says: