After the paroxysm has passed, if severe, the liver will be swollen, more or less tenderness will be developed by pressure, and in some instances, a local peritonitis coming on, there will occur the usual symptoms of that condition.

Although all the symptoms produced by the passage of biliary calculi may be present, some uncertainty will always be felt unless the body causing the disturbance is recovered from the feces. A properly-conducted search is therefore necessary. As this is so often done inefficiently and the calculus not found, an error of diagnosis may seem to have occurred. Every stool should be examined in the mode hereinafter described for a number of days after the attack until the calculus is found. It should be remembered that only air-dried calculi float on water. The stool, as soon as passed, should be slowly stirred up in water sufficient to make a thin mixture, and all solid particles removed for further examination, the thinner portion poured off, and more water added from time to time until only solids remain at last. It should not be forgotten that masses of inspissated bile, biliary sand, may produce symptoms not unlike those due to gall-stones proper, and hence all particles having the appearance of this material should be examined chemically. Place some of the supposed bile on a white plate and pour over it some drops of strong sulphuric acid, when the biliverdin will take on a brilliant scarlet color.

The discharge of particles of inspissated bile causes symptoms not unlike those due to the migration of biliary calculi, but there are points of difference. A strongly-marked case diagnosticated biliary calculi, and in which masses of inspissated bile were discharged in great quantity, will furnish the symptomatology to be now described. The onset of the paroxysms of pain is less abrupt than is the case with gall-stones, and the attacks may occur at any time; the pain also subsides more gradually, and hardly ceases at any time, but revives every now and then, so that several days, even weeks, may be occupied with one seizure. Jaundice is less apt to follow, and indeed well-defined jaundice rarely occurs in this affection. There is much swelling of the liver, also considerable tenderness, and relief is most certainly afforded by free purgation, anodynes seeming rather to keep up the disturbance, probably by checking the hepatic secretions.

Attacks of hepatic colic may be expected to recur when a calculus with multiple facets migrates, but the time when its associates may be expected to move cannot be predicated on any data now available. Single attacks may happen at intervals of weeks, months, or years. The migration of one large stone may so dilate the ducts as to facilitate the passage of those that remain behind, thus ensuring a recurrence of the seizures at an early period.

IMPACTION OF CALCULI AND MIGRATION BY ARTIFICIAL ROUTES.—The point at which impaction takes place is an element of great importance. The size of the calculus is far from being decisive as to the certainty of impaction or as to the untoward results. A not unfrequent accident is the blocking of the cystic duct at its opening, thus preventing the influx or outgo of bile from the gall-bladder. If the stone does not ulcerate through, in this position it does no damage, for the gall-bladder, as has been stated, may be closed without any apparent detriment. Just at the bend of the cystic duct, near its origin, is the point where arrest of a calculus is most likely to take place. The next most likely point is the duodenal end of the common duct. When impaction occurs a local inflammation comes on, an exudation is poured out, ulceration begins, and presently the peritoneum is reached. Adhesions usually form with the neighboring organs, but now and then perforation takes place, and bile, pus, and the calculus are precipitated into the peritoneal cavity. A fatal peritonitis follows, as a rule; but rarely the inflammation is localized, and an abscess forms which pursues the usual course of such accumulations; or adhesions may take place about the site of the perforation and prevent a general inflammation of the peritoneum. In this way a very large sac may be produced, with the ultimate result of rupture into the general cavity, although a fistulous communication may be established with some neighboring organ, permitting safe discharge in this direction.

A gall-stone impacted in one of the hepatic ducts or in the main duct, ulcerating through, may form an abscess not distinguishable from other solitary hepatic abscesses except by the presence of the concretion causing the mischief and the absence of the usual conditions giving rise to these accumulations of pus. It is probable that fatal abscesses of the liver not infrequently are caused in this way in extra-tropical countries. Adhesions forming to neighboring hollow organs or to the external integument, such abscesses discharge, carrying out the calculus with them. In this way may be explained the discharge by the intestine of calculi much too large to have passed by the natural route and unattended by the usual symptoms of hepatic colic. These gastro-intestinal biliary fistulæ extend from the gall-bladder and the larger ducts to the stomach, to the duodenum, and to the transverse colon; but of these the communication with the stomach is the least common. The adhesion of the gall-bladder or common duct to the duodenum or colon may be direct, exudations uniting the two parts without the intervention of an abscess cavity, or such a sac or cavity may be interposed. In some cases the discharge of biliary calculi is effected through these routes with so little disturbance as to escape notice, or the symptoms may be only vague indications of a local inflammation in the neighborhood of the liver.

Biliary fistulæ communicating externally, caused by the migration of calculi, are comparatively common. They have the clinical history, and are usually treated as cases, of hepatic abscess. Sometimes hundreds of calculi are thus discharged. In such instances it may be assumed that communication has been established with the gall-bladder. Hepatic abscess thus due to the migration of calculi may discharge into the pelvis of the kidney, into the ascending vena cava, or through the lung, but these places of outlet are comparatively uncommon.

COURSES AND COMPLICATIONS.—Although symptoms cease for the time being when the calculus passes into the duodenum, and although in most instances no after unpleasant effects are experienced, there are cases in which the presence of the concretion in the intestine proves to be fruitful of mischief. Calculi of very large size—from a pigeon's to a hen's egg—are also found in the intestine, without the occurrence of symptoms indicative of their migration. It has been shown that this silent migration of calculi from the liver-passages to the intestinal is not uncommon. Hepatic concretions are distinguishable from the intestinal by their crystalline form and by their composition. The former are usually polyangular, and are composed of cholesterin crystallized about a nucleus of bile-pigment, inspissated bile, or mucus. After entrance into the intestine, lime salts and mucus are deposited in successive layers, so that the form of the calculus is modified and its size increased. The solitary ovoid concretion is most frequently found in the intestine, without previous symptoms of hepatic source, and, although increased in size in the intestine, it retains its original shape. A specimen of this kind now in my possession illustrates these points. It is composed of cholesterin crystallized in radiating lines and concentric rings about a central nucleus of inspissated bile. Around the hepatic concretion there have formed layers of lime and mucus since it has reached the intestine, and after drying this rind became brittle and was readily detached. The polyangular calculus is apt to form the nucleus of a scybala-like mass of feces; hence in the search for these bodies every such mass should be broken up. An example of this has recently come under my own observation. Concretions of all sizes, having reached the intestines, as a rule pass down without creating any commotion, and are silently discharged. But various disturbances occur in some instances. Obstruction of the bowels is one of the results. A great may cases have been collected by Murchison,172 as many more by Leichtenstern,173 of impaction of the intestine produced by an accumulation of feces about a biliary concretion. A calculus may be retained in a fold or diverticulum of the small intestine, and may indeed cause a loop to be formed which in turn readily twists, becoming an immovable obstruction. This mode of obstructing the bowels is less common than the simple impaction. It is affirmed by some authorities, especially by Von Schüppel, that obstruction of the bowels—impaction—is more often caused by stones that have ulcerated through into the intestines than by those that have descended by the common duct; and this conclusion must be reached if jaundice has not been present. It is not only the size of the calculus which determines impaction, as has been stated: several may be agglutinated in one mass, and reflex spasm of the muscular layer may be induced by their presence in the bowel. Nevertheless, some enormous concretions have been found in the canal, and others have been discharged without special trouble. Hilton Fagge exhibited to the Pathological Society174 of London two gall-stones passed with the stools, measuring 2½ by 11/5 inches in long and short diameter, and Fauconneau-Dufresne175 refers to concretions of the size of a hen's egg. Mention has been made of one in the writer's possession of the size of a pullet's egg, which, until its discharge, caused a train of characteristic symptoms. These immense bodies may have ulcerated through from the gall-bladder or may have grown by successive deposits of carbonate and phosphate of lime after reaching the intestine.

172 Lectures on Diseases of the Liver, p. 573.

173 Ziemssen's Cyclopædia, vol. vii.