77. =Liver.=--The liver lies under the right hypochondrium, and passes across the middle line over the stomach into the left hypochondrium, generally speaking, as far as the left mammary line. The extent to which it can be felt below the edges of the ribs depends upon whether it is enlarged or not, as well as upon its texture, and also upon the amount of flatus in the stomach and intestines. As a rule, in health its lower thin border projects about half an inch below the costal cartilages, and can be felt moving up and down with the action of the diaphragm; but it requires an educated hand to feel it. An uneducated hand would miss it altogether. That part of it, however, which crosses the middle line below the ensiform cartilage is much more accessible to the feel; here it lies immediately behind the linea alba, and in front of the stomach, nearly half-way down to the umbilicus. Here, therefore, is the best place to feel whether the liver be enlarged or pushed down lower than it ought to be. If it be much enlarged and much lower, even the most untutored hand could detect its edge. Even if the edge of the liver be felt very much lower than is normal below the ribs, it does not necessarily follow that the liver is enlarged, since it may be pressed down by other causes--for instance, the habit of wearing tight stays. To what height does the liver ascend? This can only be ascertained by careful percussion of the chest-wall. The highest part of its convexity on the right side is about one inch below the nipple, or nearly on a level with the external and inferior angle of the pectoralis major. Posteriorly the liver comes to the surface below the base of the right lung, about the level of the tenth dorsal spine. Roughly speaking, the upper border of the liver corresponds with the level of the tendinous centre of the diaphragm; that is, the level of the lower end of the sternum. Thus a needle thrust into the right side, between the sixth and seventh ribs, would traverse the lung, and then go through the diaphragm into the liver. 78. =Gall bladder.=--The gall bladder, or rather the fundus of it, is situated, but cannot be felt, just below the edge of the liver about the ninth costal cartilage, outside the edge of the right rectus muscle. 79. =Stomach.=--The stomach varies in size more than any organ in the body. When empty and contracted (63) it lies at the back of the abdomen, overlapped by the left lobe of the liver, and in front of the pancreas. When very full, it turns on its axis and swells up towards the front, coming close behind the wall of the abdomen, occupying most of the left hypochondrium and epigastrium, displacing the other contiguous organs, pushing in every direction, and often interfering with the action of the heart and left lung. Hence the palpitation and distressing heart-symptoms in indigestion and flatulence.