Treatise on the Anatomy and Physiology of the Mucous Membranes. Bichat Xavier

I have not yet been able to observe this separation going on; that is to say, the epidermis separated at one point, and still remaining adherent at others, as in erysipelas. I have tried in vain to produce this effect by the application of an epispastic to the inner surface of the intestines of a dog.

      23. This epidermis is subject, like that of the skin, to become callous by pressure. Choppart cites a case of a shepherd, "dont le canal de l'urètre présentoit cette disposition, à la suite de l'introduction fréquemment répétée d'une petite baguette pour se procurer des jouissances voluptueuses." We know the density that this envelope takes in the stomachs of the gallinacea. In certain circumstances, where the mucous membranes are protruded from the body, as in prolapsus ani, inversion of the vagina, in the artificial anus, &c., sometimes the pressure of the dress produces in this epidermis a thickness evidently more considerable than is natural to it.