E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Barrette.
Parler à la barrette (French). To give one a thump o the head. The word barrette means the cap worn by the lower orders.
1
Et moi, je pourrais bien parler à ta barrette.
Molière: LAvare.
It is also used to signify the ordinary birretta of ecclesiastics and (probably) of French lawyers. Il à reçu le chapeau or la barrette. He has been made a cardinal.
2
Le pape lui envoyait la barrette, mais elle ne servit qu à le faire mourir cardinal.Voltaire: Siècle de Louis XIV., chap. xxxix.