23. The public and secret negotiations between Constantius
and Julian must be extracted, with some caution, from Julian
himself (Orat. ad S. P. Q. Athen. p. 286), Libanius (Orat.
Parent. c. 51, p. 276), Ammianus (xx. 9), Zosimus (1. iii.
[c. g] p. 154), and even Zonaras (tom. ii. 1. xiii. [c. so]
p. 20, 21, 22), who, on this occasion, appears to have
possessed and used some valuable materials.