Lat. Which [does or requires] nothing in vain. Which requires nothing to be done, that is, to no purpose. 2 Kent, Comm. 53. Quae non fieri debent, facta valent. Things which ought not to be done are held valid when they have been done. Tray. Lat Max. 484. Qnae non valeant singula, juncta juvant. Things which do not avail when separate, when joined avail. 3 Bulst 132; Broom, Max. 588.