obrussa — Lewis & Short
obrussa, ae (pure Gr. collat. form = xrusi/on o)/bruzon, obrȳzum aurum, f., = o)/bruzon,
Vulg. 2 Par. 3, 5; Isid. 16, 18, 2),I the testing or assaying of gold by fire in a cupel (class.).
I Lit.:
auri experimentum ignis est: id ipsum obrussam vocant,Plin. 33, 3, 19, § 59:
aurum ad obrussam,refined, pure gold, Suet. Ner. 44.—
II Trop., a test, touchstone, proof:
adhibenda tamquam obrussa ratio,Cic. Brut. 74, 258:
sic verus ille animus probatur: haec ejus obrussa est,this is its touchstone, its test, Sen. Ep. 13, 1:
si omnia argumenta ad obrussam coeperimus exigere,to put to the proof, test accurately, id. Q. N. 4, 5, 1.