“Variorum mixtura novas sæpe vires generet, in simplicibus nequaquam reperiundas longe saluberrimas.”
It is a truth universally admitted, that the arm of physic has derived much additional power and increased energy, from the resources which are furnished by the mixture and combination of medicinal bodies. I by no means intend to insinuate that the physician cannot frequently fulfil his most important indications by the administration of one simple remedy; I only contend that, in many cases, by its scientific combination with other medicines, it will not only act with greater certainty and less inconvenience, but that its sphere of influence may be thus more widely extended, and its powers so modified or changed, as to give rise to a remedy of new powers. Such a theory is amply justified by the state of combination in which certain medicinal principles are found in our more efficient vegetable remedies, while the medicinal practice founded upon it is thus, as it were, sanctioned by Nature’s own prescriptions; enter but her laboratory, and you will soon be satisfied, that many of her potent remedies do not owe their valuable powers to any one specific ingredient, but to the combined or modified energies of various, and sometimes opposite principles. This view of the subject opens an interesting and unexplored field[239] of medical and chemical research, and I shall endeavour to avail myself of the novelties its investigation may present, and of the hints it may suggest for the improvement of extemporaneous combination. By contemplating the laws by which Nature effects her wise purposes, we may learn to emulate her processes, and even in some cases to correct and assist her operations:[240] such at least has been the happy result of our labours in the other departments of natural knowledge. It is said for instance that by observing the means used by nature for preventing the diffusion of light in the eye-ball, Euler derived an important hint for the improvement of his telescope; and more lately, the structure of the crystalline humour of the eye has been successfully imitated in the invention of achromatic lenses. On the other hand, it is hardly necessary to observe to what extent these instruments of art are capable of improving and multiplying the powers of that natural organ, to the contemplation of whose structure and functions, we are, as I have just stated, so greatly indebted for their origin and perfection. So shall I endeavour to shew, in the progress of this work, that the combinations of nature, as exemplified in her more valuable remedies, are capable, if properly studied, of suggesting many important hints for improving the arrangements of art; while art in return may frequently supply the defects, or extend the advantages of natural compounds.
The objects to be attained, and the resources which are furnished, by Medicinal Combination, together with the different modes of its operation, and the laws by which it is governed, may with much practical advantage be arranged in the following order.
The utility of such a combination is obvious, whenever we desire the full and general effects of all the principles of a medicinal body in solution; thus, where the Bark is required in the cure of an intermittent fever, and the stomach will not allow the exhibition of the powder, it will be eligible to conjoin in one formula, the tincture, decoction, and extract, as exemplified by Formulæ 42, 126, 127. The necessity of such a combination may be expressed by the following canon. Whenever the chemical nature of the medicinal substance will not admit of the full solution of all its active principles in any One Solvent, and its exhibition in substance is at the same time impracticable. For farther illustrations see Form. 2, 25, 33, 38, 70, 109.
Practitoners, probably without having reasoned upon the theory, have very generally adopted the practice, of combining the different solutions of the same substance; for in the prescriptions of practical physicians we commonly find, that the decoction or infusion of a vegetable remedy is quickened by a certain portion of a corresponding tincture.
Dr. Fordyce first established the existence of the singular and important law, that a combination of similar[241] remedies will produce a more certain, speedy, and considerable effect than an equivalent dose of any single one; a fact which does not appear to have been known to any ancient physician. The earliest mention of it that I can find is by Valisnieri, the favourite pupil of Malpighi, who filled the medical chair at Padua in 1711, nearly ninety years before Fordyce published his valuable memoir on the combination of medicines, but he does not attempt any generalization[242] of the subject; he merely states, as the result of careful experiments, that twelve drachms of Cassia Pulp are about equivalent in purgative strength to four ounces of Manna; and yet, says he, if we give eight drachms of Cassia Pulp, in combination with four drachms of Manna, we obtain double the effect! How, adds the professor, can this possibly happen? Surely the very contrary ought to obtain, since four drachms of Cassia are much more than equivalent to an equal weight of Manna; the strength of the former being to that of the latter as 8 to 3.
The truth of this law of medicinal combination must be continually felt by the practitioner in the ordinary routine of his practice, viz.
Narcotics will better fulfil the intention of allaying irritation and pain, when composed of several of such medicines in combination, than when they consist of any single one, even should the dose, in this latter case, be increased. See Formulæ 3, 4, 5.
Antispasmodics acquire increased efficacy by the application of the same principle. Form. 20, 21, 22, 23, 24, 25.
Bitter Tonics are also thus exalted, see Form. 39, 40, 41. The beneficial effects, however, which arise from combinations of this kind will admit of a satisfactory explanation upon another principle; we may, for instance, consider them as medicines, differing from each other in their composition, and producing by their union an assemblage of bitter, astringent, and aromatic principles.
Aromatic and Diffusible Stimulants. There are perhaps no remedies which receive greater mutual benefit be intermixture with each other, than the individuals which compose this class; for they not only thus acquire increased force and efficacy, but at the same time they lose much of their acrimony; if, for instance, any one spice, as the dried capsule of the Capsicum, be taken into the stomach, it will excite a sense of heat and pain; in like manner will a quantity of Black Pepper; but if an equivalent quantity of these two stimulants be given in combination with each other, no such sense of pain is produced, but, on the contrary, a pleasant warmth is experienced, and a genial glow felt over the whole body; and if a greater number of spices be joined together, the chance of pain and inflammation being produced is still farther diminished. The truth of this law is also strikingly illustrated, as Dr. Fordyce has observed, by that universal maxim in cookery, never to employ one spice, if more can be procured; the object, in this case, being to make the stomach bear a large quantity of food without nausea.[243] This same principle also finds an illustration of its importance, as it regards the class of stimulants, in the following preparations of our Pharmacopœia, viz. “Pulvis Cinnamomi Compositus; Infusum Armoraciæ compositum; Infusum Aurantii Compositum; Spiritus Lavendulæ compositus; Tinctura Cinchonæ composita; Tinctura Valeriana Ammoniata; and the Confectio Opii, the elegant and scientific substitute for the celebrated Mithridate or Theriaca. The practitioner is also referred to Form. 45, 47, and to Allii Radix.”
The local action of these stimulants would appear to be placed under the dominion of the same law, and perhaps the origin of the custom, so long observed, of mixing together the varieties of snuff, may thus receive a plausible and philosophical explanation; certain it is that by such combination the harsh pungency of each ingredient will be diminished, whilst the general potency of the application, in exciting the nerves, will be increased, and rendered more grateful; the same principle will direct the formation of safe and efficient plaisters and lotions; the Emplastrum Cumini of the London, and the Emplastrum Aromaticum of the Dublin Pharmacopœia, offer examples of its judicious application.
Astringents. For illustrations see Form. 51, 58.
Emetics are certainly more efficient when composed of Ipecacuan united with Tartarized Antimony, or Sulphate of Zinc, than when they simply consist of any one of such substances in an equivalent dose. See Form. 63, 65.
Cathartics not only acquire a very great increase of power by combination with each other, but they are at the same time rendered less irritating in their operation; the Extractum Colocynthidis compositum affords an excellent example of a compound purgative mass being much more active and manageable, and less liable to irritate, than any one of its components separately taken. Additional examples of this fact are furnished by Formulæ 70, 76, 78, 79, 81, 88. In many cases, however, the fact of purgatives thus accelerating and correcting each other’s operation may be explained by considering them as substances endowed with different powers, as already demonstrated, (p. 88), and which will be more fully considered in the third division of this Essay.
Diuretics. Under this class of medicinal agents it may be observed that, whenever a medicine is liable to produce effects different from those we desire, its combination with similar remedies is particularly eligible, by which the action of the basis may be directed and fixed; thus the individuals which compose the class of Diuretics are uncertain in their operation, and disposed when exhibited singly to produce diaphoretic, and other contrary effects; it is, therefore, in such cases, highly judicious to unite several of them in one Formula, by which we increase their powers, and are more likely to ensure their operation. Formulæ 101, 103, 108, 109, 110, 111, 115, are constructed upon this principle.
Diaphoretics. Our maxim, “Vis Unita Fortior,” certainly applies with equal truth to this class of medicinal agents. Form. 122, 124.
Expectorants. More is frequently to be gained by the co-operation of these remedies than can be obtained by the exhibition of them separately, as in Form. 134, 135.
Demulcents do not appear to obtain any other benefit from combination than, occasionally, a convenience and efficacy of application arising from a suitable degree of consistence and solubility. See article “Trochisci.”
The operation of the law which has thus formed the first object of this inquiry, will be found, like every other, to have a natural and well defined limit; it is easy to perceive that by multiplying the number of ingredients too far, we shall either so increase the quantity and bulk of the medicine as to render it nauseous and cumbersome, or so reduce the dose of each constituent as to fritter away the force and energy of the combination.
The propriety of combining several stimulants, of the diffusible class, in one formula, has been questioned on different grounds. Dr. Chapman, in his work on Therapeutics, adduces some arguments on this point, which, although they fail in establishing his general position, certainly suggest an important exception to the practice in question; “by directing,” says he, “stimulating remedies, separately, we shall economise our resources in many lingering diseases.” The justness of this statement must be admitted to its fullest extent, and practitioners will, on certain occasions, do well to act in conformity with the views that suggested it; for instance, in the feeble forms of protracted fevers, where the indications are to be met with the continued action of stimulants, it will certainly be salutary to alternate the use of camphor, ammonia, and other remedies of a similar nature, in preference to presenting them all at once in combination, so that the system may not lose its susceptibility by the continued impression of the same stimulant; the same motive should induce us, on particular occasions, to employ in succession different narcotics, for each of them affects sensibility in its own peculiar manner.[244] The nervous system, as Richerand has very justly observed, may be compared to a soil, rich in different juices, and which requires the cultivator to plant the germs of a diversified vegetation to develope the whole of its fecundity; to insure a perpetual return, therefore, it will be right to sow a succession of different seeds. Hoffman also has offered us some advice upon this subject; he directs us in the treatment of chronic diseases to suspend the administration of remedies, at intervals, and afterwards to resume them, lest the system should become habituated, and ultimately insensible to their influence.
But there remains for our investigation a still more important precaution respecting this law of medicinal combination;—that, in combining substances in the manner, and for the object just related, the practitioner should be well satisfied that their medicinal virtues are in reality practically Similar, or he will fall into an error of the most fatal tendency; it has been already shewn, and I hope I shall not be considered tedious by again directing the reader’s attention to the fact, that medicines are not necessarily similar because they have been arranged in the same artificial division of remedies; in order to establish a perfect similarity their operations must be found by experience to continue similar under every condition of the human body; and that, moreover, they must owe such similarity to modes of operation which are compatible with each other, and consonant with the general mode of cure; we have only to refer to the history of Diuretics (page 92) for a full illustration of this important truth; thus Squill, Calomel, and Digitalis, are each powerful Diuretics, but nevertheless they cannot be considered similar remedies, since Digitalis will entirely fail in its effects in the very cases that Calomel and Squill succeed; and Squill will prove inert when Digitalis is capable of producing the most powerful influence; this arises from their modes of operation being dissimilar, and consequently requiring for their success such different states of the living system. Squill, it will be seen, acts primarily on the urinary organs, by stimulating the secreting vessels of the kidneys; Mercury, on the contrary, acts primarily on the absorbents, and secondarily on the kidneys; whereas Digitalis produces its effects by diminishing arterial action, and increasing that of absorption.
Dr. Blackall, in his “Observations upon the Cure of Dropsies,” has offered some remarks so valuable in themselves, and so illustrative of this important subject, that I shall take leave to quote the passage. “Many physicians,” he observes, “are fond of combining Squill, Calomel, and Digitalis, as a diuretic in dropsy; a practice unsafe, and not very decidedly possessing the merit even of being consistent. Digitalis greatly depresses the action of the heart and arteries, and controls the circulation, and it seems most unreasonable to believe that its curative powers can be independent of such an effect; on the other hand, Mercury, if it does not pass off quickly, is always exciting fever, and raising and hardening the pulse; speaking from experience, where the urine is coaguable, and Digitalis agrees, both the others are, often at least, positively injurious. On the contrary, where the urine is foul, and not coaguable, and Squills with Calomel render service, I have on that very account, made less trial of Digitalis, and cannot therefore speak of it from much experience.” See Form. 103, and the note thereon.
The individual medicines which compose the class of Diaphoretics vary no less in their primary operations, as the synoptical arrangement at page 99 very fully exemplifies; thus, in the cure of intermittent fevers, diaphoretics are useful both in the paroxysm, and during the intermission; in the first case they shorten its duration; in the second they support the tone of the extreme vessels, and prevent its recurrence; but in these opposite states of disease a very different kind of diaphoretic is required—to fulfil the first indication, a cooling and relaxing one is necessary; to answer the second, the stimulating diaphoretic is exacted; the one may be said to solicit, the other to extort, perspiration. So again Emmenagogues can only be considered relative agents, since the suppression of the catamenia may depend upon, or be connected with, very different states of the system; in some cases with a diminished, and in others with an increased state of excitement; for on many occasions the suppression of the menses is the effect, and not the cause of disease; Boerhaave has very justly observed, that it is a most dangerous error to ascribe all the diseases of young females to a retention of the catamenia, which often do not appear because the patients are disordered from other causes. If, therefore, we were to attempt a combination of the several medicines which have gained reputation as Emmenagogues, it is very obvious, that we should bring together an assemblage of adverse and incompatible remedies; nor would the physician be less inconsistent were he to combine Expectorants, without a due regard to their modes of operation; it is only necessary to observe their classification, as presented at page 102, to become satisfied how greatly the success of such remedies must depend upon their scientific adaptation to each particular case.
The class of Antispasmodics may likewise embrace remedies of the most opposite tendency, for spasm may occur under the most opposite circumstances—in an extreme condition of weakness, as in nervous affections, and in an highly excited state, as in cholic, &c.; it is hardly necessary, therefore, to point out the mischief that must arise from the fortuitous and indiscriminate admixture of the individual substances which are thus unavoidably arranged in the same artificial classification. Bark and Steel are also too often considered as equivalent Tonics; in Dropsy, says Dr. Blackall, it is far otherwise, the former being infinitely to be preferred after the dropsy of young persons, of acute disease, and of sound stamina; the latter being suited to a vitiated rather than to a feeble habit, and indicated more by a pale sallow complexion, and a want of red colour in the blood, as shewn by the paleness of the lips, than by any other signs. Need we then adduce farther illustrations of the obvious but important fact, that the terms employed to denote the different classes of remedies are frequently but relative ones, expressive of effects which are produced only in reference to a particular state of the living body? and as this necessarily varies in different states of health and disease, it follows that medicines are convertible agents, and that when we attempt to institute general rules respecting their administration, without taking into consideration the constitution and circumstances of the patient upon whom they are to operate, we shall generally be disappointed in the result. We may say of medicines what Van Swieten said of diet, “to assert that such, or such a thing be wholesome, without a knowledge of the condition of the person for whom it is intended, is like a sailor pronouncing the wind to be fair without knowing to what port the vessel is bound.” Boerhaave was so fully impressed with this truth that he exclaimed, “nullum ego cognosco remedium, nisi quod tempestivo usu fiat tale.”
Although medicines which produce the same ultimate effects by modes of operation obviously different, cannot be considered SIMILAR, in the sense affixed to the term in the present section, yet if these different modes of operation be not physiologically incompatible with each other, the union of such remedies may not only be admissible, but even useful; and it will, accordingly, constitute an object of inquiry in a succeeding section. (III. A.)
Thus it is that the system is rendered more susceptible of the influence of Mercury, by combining it with Antimony and Opium.[245] Where the stomach is insensible to impressions, the exhibition of Opium previous to, or in combination with, any active medicine, often assists its operation; this is remarkably striking in some states of mania, when emetics will fail, unless the stomach be previously influenced and prepared by a narcotic; indeed, in ordinary cases of inirritability of stomach, the addition of a small quantity of opium will often render an emetic active.[246]
So again the system, when it is in that particular condition which is indicated by a hot and dry skin, is unsusceptible of the expectorant powers of Squill, unless it be in union with antimony or some powerful diaphoretic, (Form. 134.) Squill is by no means disposed to act upon the urinary organs, when exhibited singly; but calomel, and some other mercurial preparations,[247] when in conjunction with it, appear to direct its influence to the kidneys, and to render these organs more susceptible of its operation; (103, 106.) Upon the same principle, Antimonial Wine quickens the operation of saline cathartics (69); Opium increases the sudorific powers of Antimony (124); and the purgative operation of Jalap is promoted by Ipecacuan (84). Dr. Aikin asserts that fifteen grains of the former purgative when combined with two or three grains of the latter root, will purge more than double that quantity of Jalap when administered without such an adjunct.
Sir John Pringle speaks of the advantages which may be obtained by combining an alkali with a bitter infusion, by which the diuretic effects of the former will be increased, while the latter is calculated to remove any gastric debility, and to impart a general tone to the body: there is no doubt but that Bitters, from their invigorating influence upon the primæ viæ, (see page 78) increase the effects of remedies whose operation is connected with changes in transitu, or with absorption, as in the exhibition of certain diuretics;[248] they also frequently render the stomach and bowels more susceptible of bodies that act by impression, as purgatives, emetics, &c.
We may discover the operation of such a principle in some of the more active compounds presented to us by nature: many herbs owe their efficacy to a cause of this kind. Elaterium, as I have ascertained by experiment, contains a purgative element, sui generis, (Elatin) and a bitter principle, which in itself is quite inert, and yet its presence in the compound renders the alimentary canal more susceptible of the impression of the active ingredient, and therefore increases its force. See Extract. Elaterii. The history of Senna will afford some interesting facts in farther elucidation of this subject; the leaves of this plant, like Elaterium, appear to contain an active principle, in combination with a bitter, which latter ingredient, although destitute of purgative properties, considerably increases those of the former; for if this be removed, as happens when Senna is transplanted into the south of France, the purgative principle is weakened, but may be again restored by the artificial addition of some bitter extractive. The fruit or pods of Senna[249] contain only the purgative principle, and are therefore comparatively feeble, unless the defect be compensated by art. Dr. Cullen has observed that a much smaller quantity of the leaves is required for a dose if they be infused in company with some bitter plant; and it has been found that the watery infusion of Rhubarb is rendered more purgative by the addition of Calumba.
The experiments of Seguin have established beyond all doubt that the active principle of vegetable astringents is a peculiar element, to which the name of Tannin has been given; but the efficacy of this ingredient is undoubtedly enhanced by the presence of the gallic acid with which it is usually associated, although this acid, when separated from the native combination, is incapable of producing the least astringent effect; that peculiar flavour which we so commonly experience in unripe fruits, and which we designate by the term acerbness, is the result of a combination of the astringent principle with some vegetable acid. The relative sweetness of sugar, when in different degrees of purity, depends upon the operation of the same law of combination; pure sugar, as Dr. Mac Culloch has very justly observed, however paradoxical it may appear, is not so sweet as that which is impure; the sweetness of melasses, compared with that of refined sugar, is too well known to require more than a bare mention; the vegetable extractive matter in this case, increases the effect of the saccharine principle with which it is combined; for the same reason grapes, differing very materially in their proportion of saccharine matter, may seem to the taste equally sweet, and such in fact is the case on comparing the luscious grapes of Spain, with the Chasselas of Paris; and yet the vinous produce is entirely different, the result of the one being a sweet and luscious wine, while that of the other is hard and dry, because, in truth, these grapes contain very different proportions of sugar; and however powerfully the extractive matter may modify the effects of this principle upon the palate and organs of taste, it cannot alter the quantity of alcohol resulting from its fermentation.[250] Crystallized sugar also appears less sweet to the taste than loaf sugar, but this may depend upon the different state of aggregation, and, consequently, the different degrees of solubility possessed by the sugar in these two forms.
In some cases, the addition of certain bodies will induce the absorbents to admit and carry into the circulation remedies which, in a more simple state, they would reject as injurious; this position is supported by the fact of mercury being more readily absorbed when in combination with animal matter, see Ung: Hydrarg: and it is probable that iron, in the form of a tanno-gallate, will be more acceptable than when presented in a more purely mineral state: see Ferri Sulphas.
Does it not therefore appear from the preceding remarks, that certain elements exist in the composition of vegetable remedies, as furnished by nature, which, although individually inert, confer additional strength and impulse upon the principle of activity with which they are associated.[251]
The solutions of saline cathartics appear likewise to gain an accession of power and celerity of operation by impregnation with Carbonic acid gas, depending probably upon the intestines thus receiving a degree of distention favourable to the action of the salt, (19, 23.) Certain it is that the operation of emetics, as well as that of glysters, is materially increased by the stimulus of distention.
In enumerating the methods to be adopted for increasing the energies of a remedy, by rendering the system more susceptible of its action, it is right to know that, under certain circumstances, Venesection deserves a distinguished rank amongst the Adjuvantia. The fact is strikingly discovered in the exhibition of Mercurial[252] Preparations, and some other alterative medicines. Whether the “Vis Conservatrix,” which Nature, when in a state of health and vigour, opposes to the admission of poisonous substances into the circulation, be overcome by blood-letting, is a question which I shall leave others to decide; but thus much reiterated practice has taught me, that the system in a strong and healthy condition frequently is overcome the moment the stomach becomes deranged, the circulation languid, or the general tone of the system impaired. I have frequently seen this during my Hospital practice: if a patient who has been using mercurial friction, or taking the preparations of that metal without effect, be transferred into a close and unhealthy ward, his appetite soon fails, the tongue becomes furred, and the system instantly yields to the influence of the remedy. Nauseating doses of antimony[253] frequently repeated, or the accidental supervention of any disease of debility, will be attended with the same phenomena. My practice has also afforded me an opportunity of appreciating the debilitating effects of despondency in a case of this description; a patient had been taking mercurial medicines, and using frictions for a considerable period, without any apparent effect: under these circumstances he was abruptly told that he would fall a victim to his disease; the unhappy man experienced an unusual shock at this opinion, and in a few hours became violently salivated.[254]
Venesection, moreover, increases the effects of cathartic medicines. I have often noticed this fact in contending with a plethoric diathesis; whenever the bleeding preceded the purgative, the effects of the latter have been uniformly more speedy and considerable; in obstinate constipation the same fact has been observed, and mild remedies have been known to act more powerfully, when preceded by blood-letting, than potent ones have when exhibited antecedent to it. Venesection has certainly an extraordinary power in awakening the susceptibility of the primæ viæ to remedial impressions; in some diseases, as in the Cynanche Trachealis, or Croup, so great is the insensibility of the stomach, that Emetics frequently fail in their effects; and Dr. Hamilton has given as much as a hundred grains of Calomel in the twenty-four hours: in such cases previous venesection affords most extraordinary assistance. Dr. Fothergill also remarks that emetics are more beneficial after bleeding, (Dissert. Med. Inaug. de Emet. usu.) The effects of Bark, Steel, and other tonics, are certainly influenced in the same manner; whether in any case it may be prudent or judicious to have recourse to such a practice, is a question not immediately connected with the present inquiry.
Limited must have been the experience of that practitioner who has not frequently witnessed the utility of Venesection in producing a state of system favourable to the operation of various remedies. In acute diseases, how frequently does an opiate succeed in allaying irritation after copious bleeding, which could not be made to occasion any beneficial influence previous to that operation? In Pneumonia I have repeatedly seen such a plan of treatment act like a charm upon the patient.
Purgatives also awaken the susceptibility of the body to mercurial impressions, and it is remarked by Dr. Chapman that this practice affords a resource which rarely disappoints the practitioner. This class of remedies moreover seems capable of exalting the efficacy, and indeed of accelerating the benefit to be derived from many alteratives, when administered previous to the exhibition of these latter substances; the advantages of a course of Steel medicines are undoubtedly increased by such means. The febrifugous and antiseptic properties of diluted muriatic acid (see Form. 145.) are inconsiderable, unless its exhibition be accompanied with cathartics. I beg to refer the practitioner to some cases published by me in the Medical and Physical Journal for December, 1809, in further illustration of these views. Experience enables me also to state that Diuretics are considerably assisted by similar means, having many instances in my case book of the failure of these agents before, and their successful operation after, the exhibition of a cathartic. Dr. Darwin observes that “Absorptions are always increased by Inanition,” and in support of this position refers to the frequent advantage derived from evacuations in the cure of ulcers. I have certainly seen obstinate sores in the leg cured by small and repeated bleedings. Dr. Chapman arrives at the same conclusion, although by a different train of reasoning; he states that the blood-vessels and absorbents[255] are to a certain extent “antagonising powers:” instructed by this obvious fact, we ought, says he, in the exhibition of diuretics to regulate the state of the system by interposing purgatives, or even venesection, as the state of the circulation may indicate.
Emetics also, in certain conditions of the system, would appear to render the stomach more sensible to the impression of other remedies; Dr. Eberle, of Philadelphia,[256] has remarked such an effect with respect to the administration of the Peruvian Bark.
Change of Diet and of Habits may be also classed amongst the Ajuvantia, but the young practitioner must be warned that he is not to exercise his Caduceus as Sancho’s Doctor did his wand. I have seen a young disciple of Esculapius so vex his patient, that his food became more nauseous to him than his medicine, and I verily believe his Physician was more irksome than his disease. It was well observed by Dr. Percival that the prejudices of the sick should never be contemned with wantonness, or opposed with harshness; for, silenced by authority, they will operate secretly and forcibly on the mind, creating fear, anxiety, and watchfulness. And with regard to diet it may be here stated, that no function of the body is so materially influenced by mental impressions as that series of actions constituting what is termed Digestion—the unexpected communication of any distressing event destroys the keenest appetite,[257] and converts the sensation of hunger into one of disgust at the bare idea of food: a fact which did not escape the penetrating eye of our immortal Shakespeare, for he represents Henry dismissing Wolsey from his government with these words—
If feelings of disgust are excited by the repast, the stomach will never act with healthy energy on the ingesta; and in cases of extreme aversion, they are either returned, or they pass through the alimentary canal almost unchanged: on the other hand, the gratification which attends a favourite meal is in itself a specific stimulus to the organs of digestion, especially in weak and debilitated habits. Dr. Merriman has lately communicated to me a case which affords a striking illustration of the powerful influence of the mind upon these organs: a lady of rank labouring under menorrhagia, suffered with that irritable and unrelenting state of stomach which so commonly attends that disease, and to such a degree that every kind of aliment and medicine was alike rejected: after the total failure of the usual expedients to appease the stomach and procure relief, she applied to Miss Prescott, and was magnetised, when she immediately, to the astonishment of all her friends, ate a beef steak, and continued to repeat the meal every day for six weeks, without the least inconvenience! but the disease itself, notwithstanding this treacherous amnesty of the stomach, continued with unabated violence, and shortly afterwards terminated her life.
The diet of a sick person ought never to combine too much nutriment in too small a space;[258] when so given it will even in health be followed by fermentation instead of digestion; and although we may admit the expediency of that domestic maxim, “a little and often,” yet this is to be received with limitation; no one, for instance, who possesses any philosophical knowledge, will adapt his practice to the notions of Sir William Temple, who asserted that “the stomach of a valetudinarian was like a school-boy, always doing mischief when unemployed,” and that we should therefore not allow it any interval of repose: to this I answer, that the conversion of aliment into blood is effected by a series of elaborate processes, several of which are only perfectly performed during the quiescence of the rest: it would seem, for instance, that the process of chylification is incompatible with that by which the first changes are produced in the stomach; this is evident from the well-known fact, that our appetite for food ceases when the former process commences, although the repast should, at the time, have been insufficient to satisfy the craving of nature; whereas, in diseases of imperfect, or depraved digestion, as in Diabetes, Tabes Mesenterica, &c. we find that the appetite for food is never satisfied by the most nutritive meals. It merits notice also, that whenever the stomach be called into action during the assimilating stages of digestion, the process will, in weak persons, be much disturbed, if not entirely suspended. These views have long since confirmed me in the propriety of treating mesenteric affections in a manner very different from that which is generally pursued; and I may add that the result has been very satisfactory. The plan to which I allude, consists in enforcing longer intervals between each meal, which should be scanty, and in quantity short of what the appetite may require; in this way are the unwilling absorbents induced to perform their duties with greater promptitude and activity; but it is a practice which, from the extreme anxiety of friends and relatives, the feelings of craving and hunger expressed by the patient, and the mistaken but universal prejudice respecting diet, it is always painful to propose, and generally impossible to enforce; where, however, circumstances have given a full and unreserved controul, the advantage of the plan has been most decisive.
There is still another remark which I am desirous of offering, in this place, on the subject of Diet; viz.—that in all cases of feeble or imperfect digestion, the Valetudinarian ought never to take his principal meal in a state of fatigue—and yet let me ask, whether there is a habit more generally pursued, or more tenaciously defended? Aye, and defended too upon principle—the invalid merchant, the banker, the attorney, the government clerk, are all impressed with the same belief, that after the sedentary occupations of the day, to walk several miles to their villas, or to fatigue themselves with exercise before their dinner, or rather early supper, will sharpen their tardy stomachs, and invigorate their feeble organs of digestion. The consequence is obvious,—instead of curing, such a practice is calculated to perpetuate, and even to aggravate the malady under which they suffer; by calling upon the powers of digestion at a period, when the body is in a state of exhaustion from fatigue. Often have I, in the course of my practice in this town, cured the Dyspeptic invalid, by merely inducing him to abandon so mischievous a habit.
The scientific physician, from his knowledge of the chemical composition of a medicine, and of the principles upon which its different qualities depend, is enabled to remove or render inert the element which imparts to it a deleterious operation; thus it has been found that the peculiar principle in the Spanish Fly, which so frequently irritates the urinary organs, is soluble in boiling water; ebullition in water therefore offers the means of depriving it of the power of thus acting upon the kidneys, while it does not effect any alteration in its vesicatory properties. It is upon the same principle that many vegetable substances of a very acrid nature, become harmless by boiling, or by chemical manipulation, and some of them might even in times of scarcity and want, be introduced as wholesome and nutritious articles of diet. The experiments of Westring shew that the bitterness of the Lichen Islandicus may be entirely removed by maceration in an alkaline ley, and a tasteless, but highly nutritious fecula be thus obtained; in the same manner the Æsculus Hippocastanum (Horse Chesnut) may be deprived of its bitterness, leaving a residuum which will afford a kind of bread; and according to Parmentier (Recherches sur les vegetaux nourissans,) excellent starch may be also made from it. Dr. Darwin observes, that if the roots of White Bryony be rasped into cold water, and agitated with it, the acrid juice of the root along with the mucilage will be dissolved, or swim in the water; while a starch perfectly wholesome and nutritious will subside, and may be advantageously used as food; by a similar species of address the French prepare from the acrid Arum the harmless, but highly prized cosmetic, called Cyprus powder.
There are many substances which receive a much pleasanter mode of operation by having their solubilities increased or diminished; thus the griping occasioned by several drastic purgatives is obviated by the addition of some alkali: and the nauseating tendency of Camboge, which arises from its too easy solubility, is prevented by incorporating it with some insoluble body; as in the Pilulæ Cambogiæ Comp: but the farther consideration of this question will be resumed in the fourth section of the Analysis. (iv. c.)
Numerous attempts have been made to correct the inconvenient effects of Opium, such as nausea, head-ache, and costiveness, by removing the resinous element, upon which such evils have been supposed to depend, and we have accordingly been at different times presented with a variety of Formulæ for the accomplishment of so desirable an object; (see Opium). More recently, opium has been discovered to possess two active principles, viz. Morphia and Narcotine, which would appear from the researches of M. Majendie to exert very different powers upon the animal system; the former imparting to opium its soporific, the latter, its exciting property; whence it is proposed to remove this latter principle in order to render the operation of opium milder, and at the same time to divest it of those objectionable properties which so greatly limit its medicinal utility. See Opium.
The virtues of our most important remedies are frequently lost, or much invalidated, for want of proper attention to the circumstances comprehended in this section. It may be almost admitted as an axiom that whenever an ALTERATIVE medicine acts with violence upon the primæ viæ, its energies are uselessly expended, and the object of its exhibition defeated. So again, Diaphoretics, Diuretics, and many other remedies, suffer a diminution in their effects, whenever they stimulate the stomach or bowels to excess. Guaiacum thus loses its anti-arthritic, Squill its diuretic, and Antimony and Ipecacuan their diaphoretic, virtues; the action of these substances may therefore require correction, and a medicine must be selected capable of fulfilling that intention. Opium has very extensive powers as a corrigent. See Form. 57, 100, 106, 110. Dr. Mead combined alkaline salts, when intended to act as diuretics, with opium, in order to prevent their action upon the bowels. Acetate of Lead, when administered in cases of hæmopthysis, or uterine hemorrhage, should also be guarded by the addition of a small portion of the same narcotic. Dr. Sutton, of Greenwich, has lately written a paper to shew, that where we wish to limit the operation of an emetic to the stomach, and to prevent its action on the bowels, we should add five or six drops of laudanum to the emetic draught, which in his experience has answered the purpose in question.[259] The griping and nauseating tendency of some remedies receives correction by the addition of Aromatic stimulants, or Essential oils, (69, 71, 78, 84, 85, 92,) or by small portions of a corresponding tincture, (70, 76.) It has been already stated, that the griping from Senna and resinous purgatives may be, in a great degree, obviated by the addition of alkalies; it remains to be observed, that the same remedies are also mitigated in severity, by saline purgatives, (77.) I learn from Sir Henry Halford, that in his practice he has found the addition of Extract of Hyoscyamus render the operation of the compound extract of Colocynth much more mild, and no less efficacious. Of the value of such a combination, I am myself able to bear ample testimony. Alum is corrected in its tendency to disturb the bowels by the addition of Nutmeg, (Form. 53,) or some aromatic; and the drastic operation of Colocynth may be mitigated by trituration with Camphor. There are several substances which are deprived of their acrimonious qualities by trituration with mucilage, milk, barley-water, &c. The tendency which mercurial preparations possess of affecting the bowels, is, with the exception of Corrosive Sublimate, corrected by Opium, but the acrid operation of this latter salt is more securely guarded against by the decoction of Guaiacum or Mezereon, or by the plentiful exhibition of mucilaginous drinks and broths. In certain diseases of the uterus and vagina, astringent lotions are indicated, but it may happen, as in the cauliflower excrescence, or in the oozing tumour of the labium, that such applications are too irritating; in such cases the effect of the lotion is corrected by the addition of mucilage. The enfeebling influence of Digitalis, Tobacco, and some other narcotics, is successfully opposed by aromatics and stimulants. It has already been stated that several attempts have been made to correct the operation of Opium by the application of mechanical and chemical resources; it would, however, appear that, for obviating its effects upon the intestinal excretions, the judicious addition of some purgative will offer the most effectual corrigent; and, according to my own experience, the Aloetic preparations are to be preferred upon such an occasion, as in Form. 11, 12, 13. In some cases, I have found that a combination of the watery infusion of Opium with some bitter, will secure the narcotic virtues without those consecutive effects upon the alimentary canal, which we are always so desirous to obviate; the Decoctum Aloes compositum also furnishes upon such an occasion a very appropriate adjunct. Let us remember that one of the effects of opium is to paralyse, for a time, the muscular fibres of the intestines: now experience has taught us that the remedies above directed have a peculiar tendency to augment the peristaltic motions of the primæ viæ. Upon the same principle the addition of calomel will prevent the paralysing influence of this narcotic upon the biliary functions. I have known several patients who could never take opium unless in such a form of combination.
In general, a formula contains but one corrigent; but circumstances may occur, where two different ingredients are required to obviate two very different effects, as in Form. 16, in which the Nitric acid is introduced for the purpose of counteracting the deleterious effects of the opium upon the nervous system, while the Aloetic preparation is calculated to obviate its particular tendency upon the alimentary canal.
Sometimes the unpleasant or perverse operation of a medicine may be obviated by changing the form of its exhibition, the period at which it is taken, or the extent of its dose; Dr. Cullen, for instance, found that the nauseating operation of Camboge might be obviated, by repeating small doses at short intervals. (89.)
Before quitting the present subject, it deserves notice, that there is frequently a chemical condition of the stomach that may interfere with the mild operation of a medicine, and may therefore require consideration: this is particularly exemplified in the action of those antimonial preparations which are liable to become emetic and drastic by the presence of an acid; it is, for this reason, very eligible to guard such substances with antacid adjuncts. See Antimonii Sulphuretum, and Form. 125, 128. There is also, upon some occasions, an irritable state of the primæ viæ depending upon a deficient secretion of mucus, which renders even small doses of any active medicine mischievous; mucilaginous decoctions in such a case will offer the readiest corrigent; see Scammonia.
The vinous infusion of Colchicum appears to act more violently when acid is present in the stomach; small doses of Magnesia may therefore precede, and accompany its exhibition, with advantage.