VII.

THE LIVER AND ITS DISEASES.

THE importance of the liver in the animal economy is great. It is present in all classes of living creatures except the very lowest in the scale. Few people are aware that the large soft portion of that delicious and now costly edible, the oyster, is nothing more or less than a liver. In the higher animals, its dimensions, although much less in proportion to the entire bulk of the creature, are still considerable. In man the liver is the largest gland, and weighs about four pounds, or about of the weight of the body. It is formed by an aggregation of very small masses, called lobules, each provided with blood-vessels, together with little tubes for carrying off the bile when extracted from the blood by the minute cells of which the lobules mainly consist. These tubes or bile-ducts, by their union, gradually go to form larger tubes, until the contents of all are poured into a single tube which passes to the gall-bladder or reservoir in which the bile is stored up for use. The gall-bladder is capable of containing about four ounces of fluid; it lies under the right lobe

VOL. II.

of the liver, corresponding to a point a little to the right of the middle line of the body, and just below the ribs. This storing up of bile seems to be a convenience rather than a necessity, for the gall-bladder has sometimes been found, after death, to be quite obliterated, or else the entrance to it has been so blocked up as to render it practically useless. In certain kinds of animals too, such as in the horse and the deer tribe, no gall-bladder exists.

One of the uses of the organ is to separate bile from the blood. Certain carbonaceous substances are thus got rid of, and this is necessary for the purity of the vital fluid. But in the wonderful economy of nature, this otherwise waste material becomes subservient to the wants of the system. The bile is discharged from the gall-bladder by a duct which enters the small intestine at its upper part, just below its junction with the stomach. The secretion thus becomes mixed with the contents of the intestines, through their entire extent, and seems to be the natural purgative which prevents undue accumulation in the intestinal tube. Bile also prevents the contents of the intestines from fermenting. The operation of diverting the flow of bile outward through fistulous openings has been performed on dogs, and the animals have lived afterwards for years. The chief effects of such an operation are

voracity, flatulence, and a putrescent tendency in the contents of the intestines.

Human bile is a viscid, greenish-yellow coloured fluid, having an intensely bitter taste. It is alkaline, and it is to the alkalies which it contains that the bile of animals owes its cleansing properties. Bile would seem to be concerned in the digestion of fat, but how it effects this is not understood. The quantity of bile secreted in twenty-four hours is estimated at between three and four pounds.

The liver is subject to several diseases in common with other parts of the body, as, for instance, inflammation, cancer, and abscess, but the results are modified by the peculiar structure of the organ. It is subject also to particular affections which are due to the operation of special causes. There are two things which happen in most such affections-either the organ enlarges, sometimes to an enormous degree beyond its proper size, or it contracts below it.

No cause is so productive of chronic enlargement of the liver as heat. The hot climate of India is so frequent a cause of this disorder, that to come home with a big liver and a heavy purse was a current joke in the palmy days of moneymaking in that country. By the slow influence of climate the organ becomes engorged with blood and its functions sluggishly performed. The

result is seen in the muddy or even lemon tint of skin so characteristic of Indian residents, which is due to the imperfect elimination of bile from the system.

A preparation of liver (pâté de fois gras) is well known to epicures. But it is not equally well known that this delicacy is really the product of disease. At Strasbourg, where it is chiefly made, the geese from which the livers are obtained are subjected to the prolonged action of heat. It is alleged, on good authority, that the unhappy birds are nailed by the feet to boards, so as to enforce the necessary quietude during this inhuman process. But if the pleasures of the palate are the cause of so much heedless suffering, the unoffending creatures are not without some revenge. These diseased livers are far from being wholesome food.

The small or contracted liver in the human subject is usually the result of intemperance. The surface of the liver is covered by a stout membrane, called its capsule, and from this certain fine bands, or septa, pass through it between the lobules, so as to preserve the form and consistency of the organ. The effect of alcohol, absorbed from the stomach, upon these fine membranes is to induce in them a slowly-acting inflammation, by which contraction is induced. It results from this that the secreting cells of the liver are compressed and spoiled, and its surface, instead of being smooth and

regular, becomes elevated into nodules, not inaptly compared to "hobnails" in appearance. This is also well known to anatomists as the "gin-drinker's liver."

In order to make it clear how it is that spirit-drinking is so injurious to the liver, it will be well to explain here the peculiarity of the circulation through the organ. Instead of being supplied with arterial blood, like other parts of the body, the blood which goes to the liver is collected from certain abdominal viscera, chiefly, the stomach, the intestines, and the spleen, into a large trunk, called the portal vein, by which it is conveyed to the liver, and then disseminated through it by means of the small vessels already spoken of. After having supplied the liver cells with the elements to form bile, this blood is again collected by the minute branches of the hepatic veins, which go to form two large trunks-the vena cava-by which the blood is returned into the general circulation. Now when fluids are taken into the stomach, they are absorbed directly through their coats by the veins which are so freely distributed over the inner surface of the organ. In way alcohol passes at once into the liver, and it is for this reason that the free use of simulants, when the stomach is empty of food, is so pernicious. It is a matter of common observation, that spirit drinking, after dinner is less injurious than drinking before dinner.

this