Where the biliary discharges are faulty, small doses of mercury are useful; and I prefer the hydrargyrum cum creta, on such occasions, in doses of three or four grains, and combined with two or three grains of pulvis ipecacuanhae, to every other form of combination.

363. Mr. Abernethy has justly stated that persons may be purged without having their bowels cleared of the faecal matter which may be detained in them; we should therefore endeavour to ascertain what kind or combination of purgative medicines will excite a healthy action of the bowels, without teasing them, or producing discharges from the organs themselves. The best mode of proportioning the degree of excitement to the end designed, is to take a dose of a suitable medicine at night, but short of that which may prove irritating; if it fail sufficiently to excite the organs, a similar dose may be taken in the morning: which also failing, it may be repeated at regular intervals during the day. The principle that should govern our conduct in the administration of purgatives, may be briefly stated - the excitement is to be repeated till the requisite action is induced, yet no single excitement, being such as may prove an irritant to the organ.

364. The mischief which may be produced by too active purgation seems to have been well understood by the ancients; but the modern practitioner has too frequently rejected the advice which the sages of our profession have recorded for his instruction. "He who takes a rough purge," says Plutarch, "to relieve his body from too great a load of food, may be compared to the Athenian, who finding the multitude of citizens troublesome to him, contrived to drive them out by filling the city with Scythians and wild Arabs." I do not wish to invest the Grecian historian with the attributes of a medical oracle, but we may be allowed to borrow from him a figurative allusion to illustrate the importance of a precept which cannot be too frequently or too forcibly impressed upon the mind of the medical practitioner, who, I cannot but believe, is far too indiscriminate in this practice, the idea of purgation would seem to predominate over every other, he sweeps away the meconium of the new born child, and he administers a black dose to the expiring octogenarian.

365. Where the symptoms of dyspepsia are accompanied with an evident spasmodic affection of the alimentary canal, as indicated by its inverted and convulsive movement, the malady may be inferred to exist more particularly in the muscular structure. Dr. Parry is inclined to regard such cases as distinct from those of dyspepsia, and to class them under the head of nervous irritability of the stomach; but they evidently constitute a link in the same chain, and are so intimately connected with the series that they cannot be practically separated from it. In such cases the symptoms of flatus are prominently distressing: the air which exists in the canal, and which should pass insensibly downwards, inviscating itself with the food, is thus arrested in its course, producing borborygmi and eructations from the stomach. Under these circumstances, the medicines most likely to afford relief are aloetic stimulants: I have found the decoctum aloes composition a truly valuable remedy in all affections connected with a torpid or irregular action of the muscular coats of the intestines.

On some occasions I have subjoined the infusion armoracice composition with evident advantage; and on others the oil of cajuput, in doses from three to six minims have produced much relief.

366. The administration of the white mustard seed, which has been lately revived with all the confidence which attaches to a newly discovered remedy, is certainly a useful medicine in several morbid states of the intestinal canal; but, according to my experience, it is serviceable only in such cases as are marked by alimentary, torpor. In affections attended with muscular inirrita-bility, or in those associated with a diseased state of the mucous surfaces, it is unquestionably useful. I have known it to ensure a regular alvine discharge in persons of costive habits; and I have also found it to correct that species of diarrhoea which attends a diseased condition of the mucous membrane of the intestines. These unbruised seeds were much commended by Dr. Mead in ascites, and by Bergius in intermittents, and numerous writers have extolled their virtues in stimulating the stomach and intestines. Dr. Cullen, however, observed that the seeds given in this form are never broken down or dissolved in the stomach, but pass away entire by stool; and he therefore inferred that they were incapable of producing any beneficial effect. This statement appears to have thrown so much discredit upon their value, that they fell into disuse, and they have only lately regained the confidence of the profession.

I confess myself to have been amongst those who were disposed to consider the unbruised seeds as perfectly inert; but experience has taught me that such an opinion is incorrect. The seeds consist of fecula, mucilage, an acrid volatile oil, on which their virtues depend, and which on standing deposits a quantity of sulphur, a bland fixed oil, which considerably obtunds the acrimony of the former constituent, and an ammo-niacal salt. The fixed and volatile oils may be obtained by expression, and if the mixture be submitted to the action of alcohol, the latter will be dissolved, and be thus separated from the former. It has been lately discovered, by some experiments conducted in France, that if the alcoholic solution be evaporated, a solid and crystallizable substance, distinguished by acid properties, may be obtained; and as sulphur is said to enter into its composition, it has been termed "sulphosinapic acid." If the whole seeds be macerated in boiling water, we shall at first obtain an insipid mucilage, which, like that of linseed, resides in the skin; but if the maceration be long continued, the water will become impregnated with matter yielding the odour of sulphuretted hydrogen; a proof that a portion of the volatile oil may be thus extracted; and it is probable that this process may even proceed more rapidly in the digestive canal.

In administering them, however, as a remedy, we should be cautious to prevent their accumulation in the bowels. A patient, to whom I recommended their use, informed me that his evacuations became extremely offensive, so that it is not improbable that a portion of sulphuretted hydrogen may be disengaged during their passage. Their administration evidently requires caution: if any inflammatory irritation exists, they must prove injurious: where, however, there is a sluggish or deficient secretion of the alimentary juices, I have no doubt respecting their utility.

367. The practitioner is well acquainted with the doctrines of Broussais: he maintains, that almost every disease arises from an inflammatory affection of the digestive canal; and, although the absurdity of so general a proposition must be admitted, we shall act wisely in suspecting the existence of such a state of disease in protracted dyspepsia: permanent tenderness upon pressure, and the appearance of the discharges from the bowels will generally announce such a condition: and lenient purges, the application of leeches, and a low diet, will furnish the best methods of treatment.

368. The utility of bitters, in the treatment of dyspepsia, is a very questionable and often a dangerous practice. It is, however, the popular resource of those who suffer from deficient appetite; and I am satisfied that many serious evils have arisen from its indiscriminate application. Where the disease arises from a mere want of tone, and is not complicated with intestinal irritation, such medicines are, of all others, the most effectual; a truth which will be readily deduced from the observations which I have already offered upon the operation of these agents (183).