maintained, the valve may leak. A second source of error is that the water may escape through the coronary arteries, branches of which have been cut in opening the ventricle. In testing the mitral valve the left auricle is first opened and the clots removed, so as to expose the upper surface of the valve. Then the nozzle of a syringe is introduced through the aortic valve and water forced in so as to float the mitral curtains up. The test, however, is very unreliable, because the parts cannot be placed under natural conditions. The pulmonary and tricuspid valves can, of course, be tested by methods similar to those already described. Increase or diminution in the size of the heart is best determined by weighing the organ after the removal of the clots. In certain cases, however, and in special investigations measurements of different parts of the heart are desirable. Roughly, the heart is the size of the individual's fist. The following weights and measurements are taken from Nauwerck's Sectionstechnik: 300 gr. Orth. women, 250 " Krause gives the average weight of the heart as 292 gr. 1-169 Krause. Circumference of heart at base of ventricles, 28.8 cm. (Sappey). Krause. 66 0.5-0.7 Thickness of wall of left ventricle (without trabecula), 7-10 mm. } Orth. 12.0 (W.), 12.7 (M.) Krause. 7.7 (W.), 8.0 (M.) pulmonary orifice, 8.9 (W.), 9.2 (M.) 66 ascending aorta, 7.4 cm. The directions given for the removal and opening of the heart apply only when the organ is normal or contains lesions within itself which are not in continuity with any of the vessels entering into it. In aneurysm of the ascending aorta, in thrombosis of a vena cava, and in a number of different lesions connected with the heart or with the vessels given off from it, it is important to examine these vessels and to open them while they are still in continuity with the heart. For this purpose it is often necessary or advantageous to remove the thoracic organs in one piece, so as to be able to examine the central circulatory apparatus in continuity from the front and back before disturbing any of its relations. This is done by cutting across the trachea and adjoining tissues as high in the neck as necessary or possible, and dissecting them free from the cervical vertebræ and the first ribs. Then by drawing the trachea and surrounding tissues forcibly forward the aorta and overlying organs can be easily stripped from the vertebral column as low as the diaphragm. The left hand is now placed around the lower end of the pericardial sac, the aorta, and the esophagus just above the diaphragm, and the vessels are severed by cutting between the hand and the diaphragm. More space for the examination in situ of the vessels at the base of the neck can be obtained by freeing the clavicles from all attachments above and to the first ribs and drawing them forcibly outward; this operation will be found especially useful in following up the subclavian vessels. Removal of the Lungs.-Pleural adhesions have already been spoken of. If the base of the lung is adherent to the diaphragm, it is usually advisable to remove the latter with the lung by cutting through its insertion into the ribs. According to Orth, there is less, danger of wounding the abdominal organs if scissors be used for the performance of the operation. After the lung is free it is drawn forward out of the pleural cavity, and the root of it is grasped from above downward between the separated fingers (first and second or second and third) of the left hand. The lung, thus resting in the palm of the left hand, is first drawn downward toward the pubes until the primary bronchus is divided by a nearly vertical incision above and behind the left hand. Then the lung is lifted vertically upward, and the rest of its attachments cut in the same direction from above downward by the knife held transverse and flat, so as to avoid injuring the esophagus and aorta. The procedure is the same for both lungs. Once in a great while the apex of a lung will be found so firmly adherent by dense scar-tissue that it can be freed only by using the knife. The primary or main incision into a lung is a long, deep FIG. 7.-Method of incising the lung (Nauwerck). cut from the apex to the base and from the convex surface to the root, slitting the primary bronchus, and thus not cutting it off from its branches to the upper and lower lobes (Fig. 7). To incise the left lung, place it with its inner or median surface and root downward on a board and with its base toward the operator. The left thumb steadies the lower lobe; the first finger reaches between the two lobes almost to the primary bronchus; and the rest of the fingers should hold the upper lobe. The right lung is most easily incised by placing it in the same position, but with the apex toward the operator; in other words, always place the anterior edge of a lung beneath the palm of the hand. Some prefer to place each lung on its lower or diaphragmatic surface for incision. The right middle lobe is incised separately by a cut extending transversely in its greatest diameter. The bronchi and blood-vessels should be opened up for some distance with small probe-pointed scissors—as a rule from the surface of the section-cutting through the overlying lung-tissue. In some cases, however, it is best to open up both the blood-vessels and the bronchi from the outside of the lung before incising it. The order to follow is vein first, then artery, and finally the bronchus. Secondary cuts into the lung are to be made parallel to the main incision. The bronchial lymph-glands should be incised from the outside of the lung. Organs of the Neck.-The operation of the removal of the organs of the neck is greatly facilitated if it is possible to continue the primary skin-incision up to the chin. In other cases dissect the skin from the larynx and muscles of the neck as far up as possible. In like manner free the muscles, esophagus, and trachea from their attachments laterally and posteriorly. Then allow the head to drop well back over the end of the table, and pass a long, slender-bladed knife up between the skin and the larynx, just behind the symphysis of the lower jaw, until the point of the knife appears beneath the tip of the tongue. From this point the knife is carried with a sawing motion down first one ramus of the jaw and then the other, dividing laterally the glossal muscles as far back as the posterior pharynx. The knife is next carried up behind the esophagus, and the posterior wall of the pharynx divided as high as possible. Pass the left hand up inside of the neck and draw down the tongue. Then cut the attachments of the soft to the hard palate, carrying the knife well out so as not to injure the tonsils. Any remaining attachments are usually easily severed by pressing the tongue first to one side and then to the other, and cutting close to the roof of the pharynx. Each lobe of the thyroid gland is to be incised in its greatest diameter. Next cut through the middle of the uvula and examine all of the pharynx removed. Incise the tonsils vertically. The esophagus is to be slit in the median line posteriorly, and the larynx and trachea anteriorly. The Abdominal Cavity.-The order of removal of the abdominal organs varies with different operators, and under varying circumstances with the same operator. The gastro-intestinal tract, including the liver and pancreas, may be removed before or after the genito-urinary tract. The spleen as an organ by itself is often the first to be removed. The early removal of the liver is occasionally advantageous for the sake of the additional space obtained for the examination of the other organs. It is well to practise the different methods of procedure, so that in a difficult case the best may be selected, because the examination of the abdominal cavity, especially in cases of extensive disease with numerous adhesions, is often one of the hardest tasks in postmortem technique. As a rule, it is best to follow the usual order as long as possible, gradually removing the more or less normal or uninvolved organs. Occasionally it may be advisable to remove the organs en bloc, so as to be able to approach the problem from all sides. In all cases of acute peritonitis it is best before removing any organ to search for the source of the infection, paying particular attention to the vermiform appendix, to the gastrointestinal tract, and, in females, to the pelvic organs. The order of removal of the abdominal organs adopted in this book for the majority of cases is that which seems the simplest and most natural-namely, to remove first the spleen as an organ essentially by itself; secondly, the gastrointestinal tract, including the pancreas and liver, which forms the upper layer; thirdly, the genito-urinary tract or middle layer, leaving the circulatory tract, the lowest layer, to be opened and inspected in situ. If, however, it proves neces |