Beaumont's famous experiments showed that the gastric juice, even outside the body, had an active solvent action on food, and this led Müller to suspect the presence in it of a substance acting like diastase on starch flour. Eberle, in 1834, found this principle to be present in the acid gastric mucus. Müller and Schwann found that this was true of acid extracts of the mucous membrane, but that neither acid nor extract alone had any activity. Subsequent research showed that this was a property of the gastric mucus or secretion and not of mucus in general, as was originally surmised. Pepsin has since that time been exhaustively studied, and many remarkable facts have been demonstrated, the most interesting of which is Schütz's law, so-called, which is that the quantity of pepsin varies according to the square of the amount of albumin digested. In spite of all the effort that