ἐν ᾧ φησι συντεταχέναι καὶ περι διαθηκῶν πρῶτον καὶ δεύτερον. Nearly all the mss., followed by some of the editors, read πρώτης καὶ δευτέρας, instead of πρῶτον καὶ δεύτερον, thus making Eusebius mention a work “On the first and second covenants,” instead of a first and second book “On the covenants.” It is plain from Philo’s own reference to the work (on p. 586 in Mangey’s ed.) that he wrote two books “On covenants,” and not a work “On the two covenants.” I have therefore felt warranted in reading with Heinichen and some other editors πρῶτον καὶ δεύτερον, a reading which is more natural in view of the absence of an article with διαθηκῶν, and which is confirmed by Nicephorus Callistus. This reading must be correct unless we are to suppose that Eusebius misread Philo. Fabricius suggests that Eusebius probably wrote ὰ καὶ β', which the copyists wrongly referred to the “covenants” instead of to the number of the books, and hence gave the feminine instead of the neuter form. This work “On covenants,” or “On the whole discussion concerning covenants” (as Philo gives it), is now lost, as it was already in the time of Eusebius; at least he knew of it only from Philo’s reference to it. See Schürer, p. 845.