_aggens_, _agguilla_, _iggerunt_. In ejusmodi Graeci et Accius noster
bina G scribunt, alii N et G, quod in hoc veritatem videre facile non
est.

This custom did not, however, prevail among the Romans, and Marius
Victorinus gives it as his opinion that it is better to use N than G, as
more correct to the ear, and avoiding ambiguity (the GG being then left
for the natural expression of double G).

[Mar. Vict. I. iii. 70.] Familiarior est auribus nostris N potius quam
G, ut _anceps_ et _ancilla_ et _anguia_ et _angustum_ et _anquirit_ et
_ancora_, et similia, per N potius quam per G scribite: sicut per duo G
quotiens duorum G sonum aures exigent, ut _aggerem_, _suggillat_,
_suggerendum_, _suggestion_, et similia.

N before F or S seems to have become a mere nasal, lengthening the
preceding vowel.

Cicero speaks of this as justified by the ear and by custom, rather than
by reason:

[Cic. Or. XLVIII.] Quid vero hoc elegantius, quod non fit natura, sed
quodam instituto? _indoctus_ dicimus brevi prima littera, _insanis_
producta: _inhumanus_ brevi, _infelix_ longa: et, ne multis, quibus in
verbis eae primae litterae sunt quae in _sapiente_ atque _felice_,
producte dicitur; in ceteris omnibus breviter: itemque _composuit_,
_consuevit_, _concrepit_, _confecit_. Consule veritatem, reprehendet;
refer ad aures, probabunt. Quaere, cur? Ita se dicent juvari. Voluptati
autem aurium morigerari debet oratio.