Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
I cannot do better than quote the words of Cicero [*](Or. xxiii. 77. ) on this subject. Hiatus, he says, and the meeting of vowels produce a certain softness of effect, such as to suggest a not unpleasing carelessness on the part of the orator, as though he were more anxious about his matter than his words. But consonants also are liable to conflict at the juncture of words, more especially those letters which are comparatively harsh in sound; as for instance when the final s of one word clashes with x at the opening of the next. Still more unpleasing is the hissing sound produced by the collision between a pair of these consonants, as in the phrase ars studiorum.
This was the reason why Servius, as he