THE LIVER. 531 



Source and Composition of the Bile. 



The liver is a solid organ of a dark reddish-brown color, measuring 

 10 or 12 inches from side to side, about 7 inches from front to back, 

 and about 3 inches in thickness at its posterior margin, its anterior 

 edge being, however, thin. Its average bulk has been differently esti- 

 mated at 88 or 100 cubic inches ; its weight varies from 50 to 60 

 ounces. It is the largest secreting gland in the body, and with the 

 exception of the lungs, occupies more space than any other organ. It 

 secretes the bile, the importance of which office is shown by the fact, 

 that the liver is found in all the Vertebrate, and in most of the non- 

 Yertebrate animals. 



The substance of the liver has a sp. gr. of 1050 to 1060. It has an 

 acid reaction ; its composition, in Man, in 100 parts, is said to be as 

 follows (Beale). The extractive matters mentioned include the amy- 

 loid substance named glycogen, a certain quantity of sugar, with traces 

 of inosite, hypoxanthin, xanthoglobulin, urea, and uric acid. 



Water, . 



Fatty matters, 



Albumen, . 



Extractive mat ers, 



Alkaline salts, 



Earthy salts, 



Vessels, &c., insoluble in water, 



3.82 

 4.67 



68.58 



Total solids, 31.42 



100. 



The liver is placed in the upper part of the abdomen, beneath the 

 diaphragm, reaching from back to front, and from the right side partly 

 over into the left. Its upper surface is smooth and convex, and is 

 adapted closely to the diaphragm. Its thick posterior border rests on 

 the pillars of the diaphragm and on the vertebral column, being hol- 

 lowed out opposite the latter, and presenting also a deep notch for the 

 ascending vena cava. The thin anterior border is concealed, in the 

 recumbent posture, by the lower ribs and their cartilages, but descends 

 a little below these parts, in standing, especially during inspiration, 

 when the diaphragm descends (see Fig. 13). This border is slightly 

 notched, a little to the left of the middle line. The right border of 

 the liver, nearly as thick as its posterior border, descends lower than 

 the left, and is in contact with the diaphragm; the left border, thinner 

 even than the anterior margin, extends upwards to the cardiac end of 

 the stomach. The under surface, Fig. 96, is concave and very uneven, 

 presenting various slight depressions, where it touches the stomach, 

 the duodenum, the bend of the ascending and transverse colon, the 

 right kidney, and its supra-renal capsule ; this surface is also marked 

 by special fossae or fissures for the lodgment of the gall-bladder, g, and 

 for the entrance and exit of bloodvessels, lymphatics, nerves, and 

 ducts. 



The greater part of the surface of the liver is covered by the peri- 

 toneum, by which its slight changes of position in the abdomen, are 



