When as a result of perforation of an intra-abdominal division of the gastro-intestinal tract a pneumoperitoneum develops, the symptoms produced by the air per se are generally of negligible clinical importance. The freedom from manifestations when a moderate quantity of air alone is introduced into the peritoneal cavity is exemplified by the innocuousness of artificial pneumoperitoneum performed for diagnostic or therapeutic purposes. The impressive clinical picture produced as a result of rupture of a gascontaining viscus, as for instance the stomach, is ordinarily one of peritonitis due practically entirely to the extravasation of liquid material. The escape of air, although possessing a high coefficient of diagnostic significance,1 is customarily of little or no importance from the standpoint of the symptomatology it evokes.
In exceptional instances the spontaneous accumulation of intraperitoneal air instead of constituting an insignificant element assumes the leading rôle in the production of clinical manifestations. Indeed, in