1. =Thoracic Cavity.= Presence of gas or air (pneumothorax, infections with colon bacillus, gas-forming bacillus, proteus, etc.), relative degree of pressure, odor, etc. Measure contents of each pleural sac; note character of fluid (clear, turbid, bloody, chyliform, chylous, purulent, fibrino-purulent). Normally the pleuræ are moist-shining, smooth, grayish, transparent; only a few drops of fluid found in the cavities. In cases of slowly progressive cardiac insufficiency large amounts of clear fluid may collect in the cavities just before death. Non-inflammatory collections of fluid also occur in general œdema. In these conditions the pleuræ are not cloudy or dull, while in the case of inflammation the pleural surfaces are dry, cloudy, dull-shining, injected, rough or covered with fibrinous or purulent exudate. Examine pleural surfaces particularly for evidences of inflammation, recent and old tuberculosis, primary and secondary neoplasms (carcinoma). 2. =Position of Thoracic Organs.= Locate anterior borders of lungs, apex and borders of heart. The normal lung collapses after the removal of the sternum. How much of the pericardial sac is left uncovered by the lungs? 3. =Anterior Mediastinum.= Note character of connective-tissue, amount and color of fat-tissue, number and size of lymphnodes, occurrence of œdema or emphysema. An artificial œdema may be caused by the injection of large quantities of salt solution in the pectoral region just before death. An artificial emphysema may be produced by the removal of the sternum. The condition of the large veins in the upper portion of the mediastinum should be noted before the heart is removed. Are they lax, moderately full, or distended? Secondary tumors, hemorrhages, abscesses, œdema and emphysema are the most common pathologic conditions.