Although inflammation of the liver may not be a very rare affection, it is certain that the intense degrees, which terminate in suppuration and abscess, do not occur very frequently with us. We may remark that the most various diseases of the hepatic tissues are at the bedside taken for hepatitis.

If we sum up the observations of solitary instances of well-marked hepatitis, taken in connection with the condition of the hepatic tissue surrounding wounds and recent abscesses of the liver, we find the following to be the anatomical signs of hepatitis previous to its termination in suppuration:

Inflammation never attacks the entire organ, but occurs in one or more patches. Commonly there is but one spot, but it may vary in extent, and the process is here found developed in various degrees. The viscus is swollen in proportion to the number and size of the inflammatory patches, and this tumefaction is particularly perceptible when a section is made, the turgid tissue rising above the edges of the incision and the peritoneal sheath. The parenchyma is loosened and lacerable, and the structure becomes more apparent from the enlargement of the acini, which gives the broken surface a granular appearance; the acini become altered in shape, and assume an oval form; their circumference becomes transparent, so that each acinus seems imbedded in a gray or grayish-red layer of gelatinous matter, with which it is however intimately blended. In the advanced stage of inflammation, the granulated structure disappears, the tissue seems perfectly uniform, and the broken surface has a laminated appearance. The organ has a paler color, and it is almost uniformly brown, or grayish-red in some parts, or yellowish-red or pale-yellow in others. The capillary vessels are filled with albuminous and fibrinous coagula.

If the process extend to the circumference, the peritoneal investment becomes opaque, thickened, and is easily detached; in many cases it is inflamed, and covered by an exudation of varying thickness.

Acute inflammation frequently leads to suppuration of the parenchyma and to hepatic phthisis. We then find small spots of pus occurring here and there in the infiltrated tissue, which gradually increase, coalesce, and form an hepatic abscess. The large abscesses found in the dead subject may almost always be proved to have resulted from a union of several smaller spots, by the remains of the fistulous passages that connected them, by the sinuous shape of their circumference, or by the debris of the former partitions.

The size of hepatic abscesses varies. They are often of the size of a fist, or a child's head, and may even occupy an entire lobe.

The seat of the abscess corresponds with the seat of the previous inflammation; it therefore most commonly occupies the right lobe, is generally found in the deeper parenchyma, and is often accompanied by an abscess in the left lobe, or extends into the latter.

The recent abscess represents an irregular cavity with uneven parietes, which are infiltrated with pus and consequently very friable; prolongations of the same tissue project into the cavity.

The abscess increases by fusion of the adjoining tissue, and thus assumes a round form, which becomes sinuous if a communication is established with other abscesses.

When the suppurative process has reached the boundary of the original inflammation, it meets, if no further inflammatory reaction is established in the vicinity, with infiltrated, tumid, and discolored parenchyma. In this manner the abscess may remain passive for a considerable period, retaining the shape and other characters above described. It is commonly lined by a suppurating and loosely-attached membrane. In reference to its contents, the hepatic abscess presents considerable differences at different periods, depending in part upon the communication established with the biliary vessels. The pus contained in the recent abscess is mixed with little or no bile, as the acini and the capillary gall-ducts have become obliterated by the inflammation; the bile contained in them at the commencement of the inflammatory attack, is at most found in combination with the pus. A large abscess of long standing, invariably contains pus mixed with a considerable amount of bile, which arises from the communication established between the cavity and larger gall-ducts. These are, like the bronchi, affected by a continuation of the suppurative process, and are generally eaten across in a transverse or slanting direction; and in exceptional cases only, and in very large abscesses, are they attacked and opened laterally. The pus contained in old abscesses is always discolored, generally greenish, and possessing a strong ammoniacal odor: we must undoubtedly attribute to it the extensive discoloration of the surrounding parenchyma. The bloodvessels opening into the abscess are blocked up, so that hemorrhage very rarely occurs.

Before a fatal issue takes place, the hepatic abscess may discharge its contents in different directions, and with various results. The discharge is very rarely effected into the peritoneal sac. as from the peritoneal investment having been either primarily or secondarily involved in the inflammatory process, adhesions will have been formed, which prevent this occurrence. We have to notice the. following modes of discharge: a. The hepatic abscess induces suppuration in and between the thoracic and abdominal parietes, and after a communication has been established between the former and the superficial abscess, it discharges externally by straight or sinuous, narrow or wide passages; and by this means a cure is sometimes brought about.

/B. The diaphragm may be perforated, and a discharge be effected into the right pleura, where, sooner or later, fatal inflammation is set up; or if the lung had previously been agglutinated to the diaphragm, suppuration of the pulmonary lamina of the pleura follows, and an opening being effected into the bronchi, pneumonia and pulmonary abscess supervene.

y. The hepatic pus may be eliminated by the bronchi.

d. The contents of the abscess may be discharged into the stomach, the duodenum, and the colon; and in these cases the hepatic abscess is reported to have healed.

e. A discharge may take place into the gall-bladder, or more frequently into one of the larger branches of the hepatic duct, the hepatic pus is conveyed to the intestine by a longer passage, and thus escapes.

C. Cases in which the central aponeurosis of the diaphragm is perforated, and the pus discharged by longer or shorter sinuses into the pericardium, inducing pericarditis, are very rare. They have been observed by Smith and Graves, and once by ourselves.

rj. Finally, very rare cases have occurred in which the hepatic abscess has discharged itself into large vessels, such as the vena cava; we have observed a case in which a communication was established between an hepatic abscess and the vena portae and duodenum.

A cure of the hepatic abscess is effected after the pus has been discharged by one of the above-described methods, or it may result without this occurrence from more or less complete absorption of the pus by the cellulo-vascular membrane investing the sides of the abscess; for, as soon as that portion of the parenchyma which has undergone purulent infiltration is entirely broken down, the abscess conies in contact with a surface of tissue which is in a less inflamed state, or which does not put on any reaction till now. This, however, gives rise to an exudation, which invests the smoothed surfaces of the abscess, and after being repeatedly redissolved, at last forms a permanent coating. The subjacent layer in the interim has been converted into fibro-cellular tissue, and the cellulo-vascular investment becoming incorporated with the former, induces a gradual absorption of the enclosed pus, the walls of the abscess gradually approach one another, and at last unite to form a callous cicatrix. Not unfrequently a remnant of pus, which is converted into a cheesy concretion, and gradually becomes cretified, may still be found locked up in the tissue of the cicatrix; the parenchyma, lying above the situation of the original abscess, is found collapsed; and if the abscess extended to the circumference, the hepatic peritoneal lamina forms a cicatrized, dense, shrivelled covering.

The true glandular tissue of the acini, and the interlobular tissue, are undoubtedly to be considered as the seat of the inflammation we have just examined; it must be carefully distinguished from inflammation of the capillary gall-ducts, as well as from abscess resulting from suppuration in the latter, which is characterized by its large admixture of bile. We shall advert to this form in connection with diseases of the gall-ducts.

In the same manner we have to distinguish between the hepatic abscess above described, and secondary or metastatic purulent deposits.

Induration and obliteration of the hepatic parenchyma are the more frequent result of slight and chronic inflammatory attacks. The product of inflammation solidifies, and the hepatic parenchyma becoming obliterated, is converted into a cellulo-fibrous callosity, which gradually contracts, and induces a collapse at the surface of the liver proportionate to its vicinity to the surface. If this occurs simultaneously at several points, the surface of the organ obtains an uneven, undulated, and slightly lobulated appearance. These accumulations of cartilaginous tissue are to be distinguished from the obliterations and atrophy which affect the hepatic tissue, as a result of obliteration of the portal ramifications consequent upon phlebitis.

The investigation of true chronic inflammation of the liver offers still greater difficulty, inasmuch as, in the dead subject, we generally have to deal with its products only, in various degrees of development; many cases of the so-called granular liver are probably referable to this head. At the bedside, the most heterogeneous conditions when accompanied by tedious and oppressive morbid sensations and by painful symptoms, especially by enlargement, are diagnosed as chronic inflammation of the liver.