Although mercury has not, there are some substances which have, the power of exciting the flow of bile, just as there are substances which excite the flow of saliva. Among these the mineral acids, and soluble alkalies, hold the first rank. It may seem strange that acids, and alkalies, should be here placed in juxta-position; but the reason of this arrangement will immediately appear.
According to a physiological law, acid substances have the power of exciting alkaline secretions, and alkaline substances of stimulating acid secretions.
Bile being an alkaline secretion, we can therefore have no difficulty in understanding how the mineral acids act in cases of jaundice from suppression, induced, for example, by enervation. They simply stimulate the secretion of bile.
It is not so easy, however, to comprehend the action of alkalies in similar cases. My explanation of their action is as follows:—When taken after food, and when taken on an empty stomach, the action of an alkali is entirely different. After food, and during digestion, the stomach contains a quantity of acid gastric juice, and an alkali taken then, only neutralizes the acid. On the other hand, when an alkaline substance is introduced into an empty stomach, it acts according to the general law of exciting an acid secretion; consequently, an immediate flow of gastric juice takes place. And I believe it is the excess of this acid gastric juice, which, on reaching the duodenum, stimulates the secretion, and excites the flow from the gall-bladder of the alkaline bile, just as the mineral acids do under similar circumstances. One remark further is, however, necessary. The quantity of alkali employed for the purpose of stimulating the secretion, or of exciting the flow of the already secreted bile must be small, for if much be used, the greater part of the gastric juice will be rendered useless, in consequence of its being neutralized as fast as it is secreted. It may be laid down as a general rule, that when we desire to increase the flow of bile by means of a mineral acid, the acid must be given after food. When, on the other hand, an alkali is selected for that purpose, the alkali must be administered before food.
For obvious reasons, both alkalies and acids are counter-indicated in cases of jaundice resulting from active congestion of the liver; and it is equally evident that they can be of no direct service in jaundice arising from occlusion of the bile-duct, where our object would be rather to diminish than to increase the secretion of bile.
Alkalies, or at least some alkalies, possess certain other properties besides those to which allusion has just been made, which may be usefully turned to account in the treatment of hepatic diseases. For example, we have been long told that alkaline carbonates are valuable remedies in cases of gall-stones, in consequence of their possessing the power of dissolving biliary calculi. Now, although I am not sufficiently enthusiastic to believe that alkalies can have much effect in dissolving gall-stones when once formed, I nevertheless believe that they are of the utmost advantage in preventing and arresting their deposition. The alkali to which I give preference is the carbonate of soda, and the reason why I prefer it to the carbonate of potash, is in consequence of my believing that the advantages derived from administering alkalies in cases of incipient gall-stones are entirely due to our being able thereby to increase the amount of glycocholate, and taurocholate of soda present in the bile; both of which substances, separately or combined, retain cholesterine in a soluble form; and, as is well known, by far the greater number of biliary calculi are composed almost entirely of pure cholesterine.
The carbonate of soda has yet another advantage. It was long ago observed by Dr. Prout that gall-stones are very common in persons of a gouty, and rheumatic tendency of body, a fact which I have myself been able to confirm on several occasions, by making a quantitative analysis of the uric acid in the twenty-four hours' urine, as recommended at [page 56]. In such cases the carbonated alkali is of double service, for while increasing the solvent in the bile, it at the same time counteracts the uric acid diathesis. In a case of gall-stones, in a woman aged 36, where there was an almost daily deposit of fine crystalline uric acid in the urine, it was found necessary to continue the administration of ten grains of soda, with five of rhubarb, three times a-day during two months, before this tendency to lithic acid deposit was entirely overcome.
Recently I have prescribed lithia water to persons of the uric acid diathesis in whom I had reason to suspect the existence of a predisposition to gall-stones; and when it was necessary to combine it with stimulants, sherry has been the wine selected. For some further remarks on the treatment of gall-stones, see pages [114], [119], and [123].
There is a remedy to which I wish to call special attention, namely, benzoic acid. This substance was first recommended as a remedy in jaundice by a German physician, about six years ago. Since then, I have tried it several times, and found it of benefit in jaundice arising from suppression. In those cases of obstruction, on the other hand, in which I tried it, it appeared to be anything but beneficial. I give it in the form of pill, three times a day. Dr. Green, one of my former pupils, who has just returned from India, tells me that he acted on my suggestion, and tried it in a case of well-marked jaundice, following an attack of delirium tremens; and that by the end of eight days it would have required an experienced eye to detect the tinging of the conjunctivæ.
The following may be cited as a tolerably good example of the value of benzoic acid in cases of jaundice from enervation:—