I shall delay entering into an explanation of the mechanism of jaundice from obstruction, until I come to the consideration of what may be termed _Permanent Jaundice_, as in that case one explanation will do for all.
JAUNDICE AS A RESULT OF THE ACCIDENTAL OBSTRUCTION OF THE BILE-DUCTS.
The second class of cases, namely, those in which the obstruction is in the course of the ducts, are of frequent occurrence, and in them the jaundiced state is usually merely transient, for no sooner has the obstruction been removed, than the jaundice begins to disappear. The most common cases of this kind are those arising from gall-stones. As every one is familiar with their history, I may merely mention, that we may have gall-stones, and even all the most painful { 43} symptoms of gall-stones, without the slightest trace of jaundice. This, I believe, arises in the following manner:--
Firstly,--The majority of gall-stones are formed in the gall-bladder; their formation being due to the accidental deposition of the less soluble parts of the bile, either as a consequence of these ingredients being present in excess, or in consequence of the solvent, whose duty it is to retain them in solution, being in reduced quantity. The deposition or formation of gall-stones follows exactly the same law as the deposition or formation of stone in the bladder.
Secondly,--In some cases the gall-stone, or stones--for there may be many, even hundreds, remain in the gall-bladder during the whole life of the individual, without giving rise to any disagreeable results, either as regards pain, or jaundice. In other cases, the gall-stones--and this usually happens when they are small--get into the cystic duct, and become lodged there; and in such a case, although the patient may suffer intense pain, there is still no jaundice. Moreover, it is not until the stone or stones have passed down into the common bile-duct, that jaundice is at all likely to be induced by them. For while a stone remains in the cystic duct, although it may completely block it up, and effectually prevent the bile either { 44} entering into or escaping from the gall-bladder, yet, as in this situation it cannot offer any obstacle to the direct flow of the biliary secretion from the hepatic tissue into the intestines, there is no retention, and consequent absorption of bile. In fact, the presence of the stone in this position, in as far as the biliary function is concerned, only reduces the patient to the state of a person in whom the gall-bladder is accidentally absent; or to that of a horse, or other animal, in which the absence of the gall-bladder is a normal condition.