The most remarkable are those entirely abnormal contents of the biliary passages, which are either the product of textural changes and morbid processes in their coats, or which after being generated externally, are conveyed into the cavity by various passages. We allude to the sero-albuminous fluid of dropsy of the bladder, to mucus, to pus that has been formed in the biliary passages, or in hepatic abscessed, to blood derived from cancerous growths, to acephalocysts from the liver, lumbrici from the intestine, etc.

The bile itself presents great varieties as to quantity, but more still as to quality; in the majority of instances the anomaly has its origin not so much in disease of the liver, as in morbid conditions of other organs, especially of the intestine and of the portal blood.

As regards quantity, the bile is found accumulated to a large amount in the biliary passages and intestine, or it is remarkably scanty. It is to be observed that in the latter case the deficiency is sometimes compensated by the saturated condition of the fluid.

The qualitative anomalies of the bile are more numerous and important, and affect both its physical and its chemical constitution.

The color of the bile varies extremely: it may be pale yellow, ochrey, orange-colored, yellowish-brown, blackish-brown, black, or of all the different shades and tints of green. The consistency of the bile generally increases in a ratio with the increased depth of color, varying from the fluidity of water to the density of tar and of calculous concretions. In taste it varies as to the amount of bitterness, but it may also be more or less, or entirely, saccharine, saline, sour, alkaline, acrid, or insipid.

In reference to its chemical constitution, the bile presents, as might be inferred from its physical qualities, numerous deviations from the correct standard; the chief constituents vary in their relative proportions, or they are replaced by new anomalous substances.

The biliary calculi are of considerable importance. They originate in a morbid constitution of the bile, which may be abnormal when secreted, or subsequently become so from stagnation and retention. They occur in the biliary passages external to and within the liver, but more especially in the gall-bladder.

Here too we find numerous variations with regard both to physical qualities and to chemical composition.

They vary in size from a millet-seed to a hen's egg, and more. We generally find the largest to be formed by several materials disposed in layers, with a preponderance of fatty matter. The larger they are, the less numerous will they be; sometimes several hundreds of small calculi are discovered in the gall-bladder.

Their form and surface vary much. Single calculi are commonly round, oval, or cylindrical; when very large, so as to occupy the entire cavity of the gall-bladder, they are frequently slightly curved; if several are present at the same time, they mutually prevent their enlargement, and in consequence of the friction and pressure they exert upon one another, they assume cubical, tetrahedric, prismatic, or irregularly poly-hedric shapes, with convex or concave surfaces.

The calculi found in the ducts are generally cylindrical, occasionally branched, or entirely amorphous. Their surface may be smooth and unctuous to the touch, or rough, racemose, uneven, of a mulberry appearance, crystalline, or branched.

The texture of the calculi may be uniform or varied, in proportion as they consist of one substance, or of several layers. Many show no distinct arrangement; some have an earthy pulverulent fracture, or a fibrous, striated, laminated, micaceous texture, presenting a glassy, silky, or asbest-like gloss on fracture, as is particularly observed in calculi consisting of cholesterine.

Generally speaking, they are not very hard, and may, when first removed from the body, be easily compressed between the fingers. On drying, they crack and fall to pieces, andj at last become pulverulent, which is particularly the case with those concretions which consist of inspissated bile or biliary resin.

In color they vary considerably; they may be milk-white, bluish, chalky, light or dark-yellow, brown, black, or colorless, or transparent, with a slight yellow or green tinge. Those of an ochrey, red, green, and blue (bronzed) color are unusual. Sometimes we find them spotted, and either of a uniform color throughout, or varying in layers, or at least containing a differently colored nucleus.

Chemical analysis shows the biliary calculi to consist mainly of inspissated bile, biliary resin, coloring and fatty matter, and the calculus may be either formed of one of these substances or of a mixture of several. In the latter instance they either interpenetrate one another, or are disposed in distinct layers, which are distinguishable by their color or texture.

Large biliary calculi generally contain but a small portion of inspissated bile; the latter often forms small irregular concretions in the gall-bladder, or larger cylindrical and branched concretions in the gall-ducts, or it serves as a nucleus to the various calculi of the gall-bladder. The resin and pigmentary matter of the bile enter into the composition of the majority of gall-stones, and that frequently to a considerable extent.

Cholesterine almost always preponderates; it frequently occurs in a pure state as a white, mother-of-pearl like, shining, or opaque fatty investment, or in distinct layers of a striated texture, which are separated by colored resinous layers; it may also exist in an isolated form, deposited round a colored nucleus, and give rise to translucent calculi of a striated and distinctly crystalline texture. In the latter case we generally find that small solitary calculi, in the former very large calculi result.

Picromel commonly occurs but in minute quantities, in biliary calculi; the various salts they contain form but a small proportion compared to the amount of the above-named constituents. Those concretions in the gall-ducts which are found to consist of carbonate of lime, are not products of the bile, but of the blennorrhoic mucus and pus of the gallbladder.

The calculi found in the same gall-bladder generally resemble one another in composition, shape, and size; although we meet with occasional exceptions from this rule. Thus in dropsy of the gall-bladder, we often find, beside the calculus which closes up the cystic duct, and which is of an old date, and of complicated structure, a second crystalline calculus, of more recent formation, which consists of pure cholesterine.

The calculi are either unattached or sessile. In the latter case they may be grasped and retained by a portion of the bladder, or be agglutinated to its internal surface by exudation, or they may be included in compartments, formed by an inspissated albuminous product of the gallbladder, on by organized lymph which has been converted into fibrous tissue. Small calculi are also occasionally formed within small saccular dilatations of the biliary mucous membrane, and may appear to lie external to the cavity of the bladder.

Biliary calculi frequently cause irritation, inflammation, and subsequent suppuration of the coats of the gall-bladder, which may terminate in various ways. Cicatrices are often left, which more or less diminish the cavity. They may induce complete occlusion of the biliary passages, followed by dilatation and retention of bile. We must, however, observe that sometimes, owing to the extreme distension which the biliary passages are capable of, calculi of the size of a hen's egg are enabled to pass.

Biliary calculi are of common occurrence. We have observed that their formation is peculiarly coincident with excessive deposit of adipose tissue and with carcinoma.

The entozoa occurring in the human gall-bladder are the endogenous acephalocyst of the hepatic parenchyma and the distoma hepaticum.