In reference to this subject we may direct the reader to the preceding remarks, to the general investigation of the abnormities of serous membranes, and to subsequent paragraphs. At this place we merely allude to the presence of gas (meteorismus abdominalis) and of serous fluid (ascites) in the peritoneal cavity. The former occurs in rare cases as a joint product of the inflammatory process, or as the result of decomposition affecting an exudation of low vitality, and in extremely rare cases as the product of a deranged secretion; but it is more frequently a mere extravasation of intestinal gas, resulting from rupture, gangrene, ulceration, or softening of the stomach or intestine.

Extensive accumulation of serous fluid gives rise to ascites. It is very often the result of an hydropic cachexia, dependent upon a variety of causes, and is then commonly associated with other dropsies. In the first instance, the predominant hydropic symptom is mostly the consequence of granular liver, heart-affections, frequently of Bright's disease of the kidneys; it accompanies carcinomatous formations on the peritoneum, etc.