France in the 17th century was not kind to the impotent as the inability to consummate a marriage* was grounds for divorce. Women who wanted to be rid of their husbands would accuse them of not being able to maintain an erection and it was then up to the husband to prove that he could.
A hands-on testimony could be demanded by either party to a case, either to prove or to disprove accusations of sexual inability under any of the three heads of valid sexual congress, be it erection,intromission, or ejaculation
Simply achieving an erection was not enough. Instead, literally hordes of experts would poke, prod, molest, and scrutinise the penis, assessing it for size, tensile strength, hardness, and curvature, all of which were deemed to play a part in ensuring capacity for intercourse.
Furthermore, the volume, size, and pendulosity of the “cullions” or testicles was also open for debate. Given all that, it really is no surprise that even with the greatest “libidinous provocation” of the duly assigned matrons in the case, having one’s member handled by a bevy of critics, combined with the pressure of knowing that this particular stiffy was nearly all that stood between the candidate and the loss of half his worldly goods, was almost certain to render even the most hot-blooded male barely able even to present a semi.
Even where the sexual capacity of the woman was not in question, a genital examination was still carried out as a matter of course. Why? Because if the man that the unfortunate woman married was indeed impotent, then she’d still be a virgin, at least in theory. Therefore it was necessary to discern such a state, not an easy task by any token. Theories abounded. Some thought that after she were deflowered, the maiden’s nose would change from a rounded, chubby shape to a more gaunt and pointy mien. Others looked for it in the manner in which she walked. But one system which most tended to agree on was a genital examination, in order to detect a hymen or the tight, narrow character which, to the minds of the alleged experts, signified that the woman had yet to experience penetration.
Even if her privy parts were found to be too distended, this was still not a cast-iron disproof of the impotence allegation. As one trial lawyer put it, a woman’s husband might “have done more work with his ten fingers over the past year than thought possible.”