There remains a consideration of some weight. Until this century it was
common to bind together several books (not merely pamphlets) in one
volume. What books have been found in the same binding with the “1468”
volume? Four copies of the Jerome are, or are known to have been, bound
with several other treatises (see p. 252). One is bound with (and
before) the Aretinus of 1479, and it is interesting that though a few
leaves of modern paper now separate them there is an offset of the first
page of the Aretinus on the last page of the Jerome, showing that the
Aretinus was bound with the Jerome before the former was entirely dry.
No conclusion however about the date of the Jerome can be drawn from
this and whatever presumption of synchronism might be raised is removed
by the fact that the well defined stains at the end of the Jerome and
beginning of the Aretinus do _not_ run from the one to the other. A
second copy was bound with seven others, only two of which are dated,
1478 and (the Oxford Aegidius) 1479: one of the undated is about 1485
(Perottus). A third copy was bound with four preceding treatises, of
which the only dated one was the first, the Oxford Aegidius of 1479. A
fourth has five pieces with it, the first two of which are of about
1480, the Jerome is third, the fourth is of 1485, the fifth is undated,
and the last is of 1486 or 1487.
Clearly we are on very unsafe ground when we base any conclusion on
these companion treatises, and our hesitation is not lessened when we
notice that the only copy of the ©Vulgaria Terentii© (Oxf., not later
than 1483) which is bound with other treatises, occurs after books dated
1488 and 1486, the rest being without a date.