[Footnote 43: From Leo I. (A.D. 470) the Imperial ink, which
is still visible on some original acts, was a mixture of
vermilion and cinnabar, or purple. The emperor's guardians,
who shared in this prerogative, always marked in green ink
the indiction and the month. See the Dictionnaire
Diplomatique, (tom. i. p. 511 - 513) a valuable abridgment.]