[2503.] Hardening. A vocalic i or u is sometimes made consonantal before another vowel: as, abi͡ete, ari͡ete (Verg.); cōnsili͡um (Hor.); omni͡a (Lucr.). See [117] and [83].
This usage is sometimes included under Synizesis ([2499]), while some grammarians term it Synaeresis ([2500]).
[2504.] Softening. Conversely, a consonantal i or u sometimes becomes vocalized before a vowel, thus giving an additional syllable: as, silüae for silvae (Hor.); ēvolüisse for ēvolvisse (Ov.). See [52].
This usage is sometimes included under the name Dialysis ([2501]).
[2505.] Diastolé (Greek διαστολή, a drawing asunder). A syllable which in verse of the classical period is generally short is sometimes used as long for metrical convenience. The syllable so employed generally falls under the verse-ictus, and in most cases is immediately followed by the principal caesura, or by a pause in the sense. Examples are:
terga fatīgāmūs hastā, nec tarda senectus, V. 9, 610.
tum sīc Mercurium adloquitūr ac tālia mandat, V. 4, 222.
caeca timēt aliunde fāta, H. 2, 13, 16.
In many such cases this lengthening is not arbitrary, but the “lengthened” syllable is one that was originally long (see [132]).
[2506.] The enclitic -que is sometimes lengthened under the ictus when another -que precedes or follows in the arsis: as, cālōnēs famulīque metallīquḗ caculaeque (Accius).