a capital, leading, or decisive experiment; thus termed, either on account of its being like a cross, or direction-post, placed in the meeting of several roads, guiding men to the true knowledge of the nature of that thing they are inquiring after; or, on account of its being a kind of torture, whereby the nature of the thing is as it were extorted by force.

**EXPHORESIS.** See Oratory, n° 85.