1911 Encyclopædia Britannica/Coulisse

COULISSE (French for “groove,” from couler, to slide), a term for a groove in which a gate of a sluice, or the side-scenes in a theatre, slide up and down, hence applied to the space on the stage between the wings, and generally to that part of the theatre “behind the scenes” and out of view of the public. It is also a term of the Paris Bourse, derived from a coulisse, or passage in which transactions were carried on without the authorized agents de change. The name coulissier was thus given to unauthorized agents de change, or “outside brokers” who, after many attempts at suppression, were finally given a recognized status in 1901. They bring business to the agents de change, and act as intermediaries between them and other parties. (See Stock Exchange: Paris.)