# Transactions of the Provincial Medical and Surgical Association/Volume 1/On the objects and modes of medical investigation

ON THE OBJECTS AND MODES
OF
MEDICAL INVESTIGATION.
BY EDWARD BARLOW, M. D.
Physician to the Bath United Hospital, and to the Bath Hospital, &c..
THE objects of the provincial medical and surgical association are fully and clearly stated in the excellent address, which Dr. Hastings, its Founder, delivered at the inauguratory meeting, and which forms the appropriate introduction to this, its first volume of transactions. In order to promote the fulfilment of these purposes, it may not be inexpedient, at the outset of an undertaking so comprehensive in its designs, and which promises to elicit much valuable knowledge from a class of practitioners eminently qualified for affording useful instruction, to discuss briefly the objects and modes of investigation, by which pathological truths can be best established, and sound science most successfully cultivated.
While the association embraces in its designs the whole range of medical science, it is to the improvement and diffusion of practical knowledge its efforts will be more especially directed, this being the great end for which the science exists. Of this knowledge facts are the basis, and speculation is of value only ​so far as it connects the facts with such physiological and pathological principles as are already established; or, as it can succeed in deducing other principles from the facts supplied. In both respects much caution is necessary, especially in the latter, the tendency to generalise from insufficient data, so prevalent in speculative minds, requiring to be carefully watched, and rigidly restrained within its legitimate bounds.
It can hardly be but that the modes of investigating disease ordinarily followed, labour under some radical errors or defects, else the researches of ages, pursued, as they have been, with exemplary diligence, and, in many splendid instances, by minds of the first order of intellect, must, ere this, have rendered our knowledge of the nature and treatment of disease more certain and more complete. Further efforts are required, and better modes seem greatly needed. The present essay makes no presumptuous pretension to supplying this want, it being only a very humble attempt to point out some defects which impede the advancement of useful knowledge, and to suggest some improvements by which greater accuracy, both in the observation of morbid phenomena, and in the adaptation of remedies, may be attained.
It is by all agreed, that of medicine as of all natural science, facts are the foundation. The term is imposing, and apt to gain, for whatever is so denominated, an unreflecting belief. It seems to imply something obvious, tangible, which cannot mislead, and opposed to which all reasoning is fruitless; a persuasion which is embodied in the ​popular adage of facts being stubborn things. It would be well if all alleged facts were real truths; but it is far otherwise. Medical facts, at least, have not sustained this high character. On the contrary, they have, somehow, fallen into particular disrepute, and it has been sarcastically remarked, that nothing can be less deserving of credit than medical theories, except medical facts. By this sarcasm, however, no moral imputation is intended, nor should it be construed otherwise than as implying the difficulties of the subject, and the imperfection of human intellect.
Facts, then, being the foundation of medical science, the first requisite in all attempts to improve it, is to ensure all alleged facts being real truths. Medical facts are principally derived from the observation of phenomena during life, and the examination of structure after death. In both, many sources of fallacy exist, against which the medical enquirer should be on his guard. It will be convenient to consider, in the first place, those which regard the latter subject.
No facts in medicine are relied on with more confidence than those which dissection displays. Yet the results of necroscopic examination are fraught with fallacies, which it requires great familiarity with the aspects of natural and morbid structure, and intimate knowledge of the changes which take place in them, to detect and avoid. Organic lesions, when far advanced, are sufficiently obvious; but the changes induced by acute disease, and the vascular derangements consequent on inflammatory action are oftentimes equivocal, and very liable to be confounded ​with appearances which, occurring after death, have no necessary connexion with the vital actions which preceded it. On this subject M. Andral's excellent treatise on pathological anatomy affords much valuable and precise information. A brief epitome of his views in this respect, will best convey what I here wish to advance.
In all organized living matter, three great fundamental actions are uninterruptedly going forward, namely, capillary circulation, nutrition, and secretion. In man, and in those animals occupying a place near him in the zoological scale, a fourth action, derived from the nervous system, is superadded, which exercises a powerful influence and control over the others. The materials of nutrition and secretion being derived from the blood, the qualities of this necessarily exercise also a great influence over both processes. Hence M. Andral, in investigating the various morbid alterations to which the several structures of the body are liable, considers them under five heads, according as they involve, respectively, lesions of circulation, nutrition, secretion, the blood, and innervation. Lesions of circulation, to which, alone, I mean here to advert, he divides into two classes, according as blood is excessive or deficient in the capillary vessels, distinguishing the first by the term hyperæmia, the second by that of anæmia. Hyperæmia, or preternatural accumulation of blood, he sub-divides into four species, active or sthenic hyperæmia, produced by irritation; passive or asthenic, resulting from diminished tone in the capillary vessels; mechanical, from an obstacle to the venous circulation; and cadaveric, or post ​mortem, being the result of those physical and chemical laws to which all inorganic matter is subject, and to which all organised bodies are also subjected when the vital spark ceases to animate them. The first three of these I shall pass over as not essential to my present purpose, confining my observations to the last, which comprises the several sources of fallacy by which anatomists, in the examination of bodies after death, are most liable to be misled.
The contractility of tissues which resides in the small arteries, continuing after the heart has ceased to beat, hyperæmia may be produced at the moment of death, and thus appearances may be presented in which the morbid actions, antecedent to death, had no share.
But hyperæmia may also be produced at certain periods after death, from several causes. Of these, hypostasis, or dependent position, is the most remarkable. The phenomena of this, as frequently exhibited in the skin, are familiar to all, and cannot be mistaken. But it continually takes place in internal parts, and may be produced at pleasure according to the position in which the body is placed. The degree is also influenced by the time which intervenes between death and dissection. A body, partially examined, will present different phenomena, and exhibit other congestions, if the examination be renewed the following day.
During life, the blood contained in its vessels can pass off only by their extremities, the vital powers of the tissues preventing transudation through their sides. There is reason to believe, however, that, ​after death, such transudation is capable of taking place. The possibility is proved by a simple experiment. If prussiate of potash be introduced into a vein or artery of a dead body, and some sulphate of iron be deposited outside the vessel, a blue colour will, in a short time, manifest that the prussiate has reached the iron through the sides of the vessel. The transudation of bile, which in almost every dead body stains the adjacent parts, is a familiar exemplification of this mode of escape. In still later periods after death, several chemical affinities come into action, and produce appearances of hyperæmia which are liable to be mistaken for the effects of disease.
These statements, taken from Andral, brief and imperfect as they are, may yet suffice to shew how much care is required in discriminating the changes produced by disease, from those to which mere physical or chemical influences give rise; and to suggest to those who undertake the examination of dead bodies, a due reserve in pronouncing determinately respecting the cause of death, or of the pre-existing disease, from the appearances which dissection displays. On this subject, much greater accuracy is needed than is generally evinced. For such examination, it is too often deemed sufficient for the operator to be expert in the use of the knife. This is a great error; no anatomical process requiring from the person performing it, such matured knowledge, so much familiar acquaintance with natural structure, and so much pathological information. As in Chemistry, the analysis of mineral waters is said to demand the largest portion of chemical skill ​on the part of the operator, so in Anatomy, is the examination of dead bodies, for the purpose of determining morbid lesions, an exercise of skill, surpassing what any mere surgical operation can call forth.
The history of physic abounds in evidences of inferences respecting morbid actions being hastily deduced from the appearances presented by dissection. This fruitful source of error should be sedulously guarded against by all who aim at any precision in reporting the results of necroscopic inspection.
To one more point only in relation to this subject, shall I here call attention. In examining the brain, the practice of slicing should be for ever abandoned. As this rude and in artificial mode is utterly incapable of displaying the natural structure of the organ, so is it unfitted for demonstrating those lesions which disease induces. Considerable disease may exist, and yet wholly escape detection under the mode of examination generally practised. Whoever has seen Dr. Spurzheim demonstrate a diseased brain, must be sensible of the vast superiority of the mode which he pursues. The examination being, in the first instance, thus conducted, the substance of the cerebral mass may then be sliced, in order to ascertain the changes which its internal structure may have undergone.
The remaining subject of this Essay may now be arranged under two heads, namely, the investigation of disease, and that of the operation of remedies.
The term disease applies to any deviation from a healthy state. It must have direct reference, therefore, to a state of health, and, accordingly, physiology must be the basis on which all pathology must be ​founded. But it is more particularly used to denote certain combinations of morbid symptoms, to which a character of individuality is assigned, and which are thence more especially denominated diseases. These have been classed according to their real or supposed relation, and this branch of medical science is distinguished by the name of nosology. It is to the investigation of nosological diseases, that the labours of medical enquirers have been most assiduously devoted. These preliminary statements lead us to one source of the imperfection which has hitherto attached to such research; specific diseases attract attention only when the aggregate distress, or some symptom more prominent than the rest, impresses the conviction of the frame being out of order. The symptoms are now examined, and, according as the assemblage corresponds with some nosological character, is the name assigned. This is the first step in the medical problem, “ the disease being given to find the remedy;” and so abundant are the curative means laid down in books, that the medical student, who has just escaped from the schools, confident in the resources of his art, conceives he has only to determine the disease in order to subdue it. A very little experience of actual disease, suffices to disabuse him of this notion. He soon finds that the nosological character of disease is seldom, if ever, realised in any individual case. However well marked this may be in its leading features, it is characterised by others of which his nosology takes no count. Many instances, and of formidable disease, will he meet with, which cannot be referred to any nosological character; and, if he ​be ambitious of noting all his cases, according to nosological arrangement, precision, in this respect, must be continually purchased at the expense of truth. I, at least, have long, and with oft renewed efforts, endeavoured to attain this enviable accuracy, but have never yet succeeded. The cause of this discordance between nosological character and actual disease, is easily discovered. The character is not drawn from any individual instance, but is derived from numbers, and, in this way, a perfect disease is supposed to be depicted. Of this each feature may, no doubt, be true to nature, yet the assemblages are very rarely found so combined; whence nosological character proves rather an ideal exemplar, than a true prototype.
But, waving this source of imperfection, the mode of judging diseases by nosological character, is fraught with further evils of an influence injurious to medical science. The character itself, however perfectly drawn from accurate observation of numerous specimens, must, of necessity, be incomplete. It may pourtray, with sufficient accuracy, the assemblage of symptoms co-existent at a particular stage of disease; but this stage is not the commencement, and to refer to it as if it were, can be productive only of confusion and error. Antecedently to this stage there is always an interval of deranged function, marked by its appropriate phenomena, and capable of being ascertained by suitable examination. This antecedent stage is essential to a complete history of the disease, and an accurate knowledge of it is, perhaps, even more necessary than of any other, inasmuch as it best displays the morbid actions by which ​the specific disease is generated, and acquaintance with it is absolutely necessary for connecting the morbid condition with the previous state of health. Incipient disease has been too much overlooked. Its phenomena are as cognisable as any of the more advanced, and a clear conception of the progressive changes by which a state of health passes into that of disease, furnishes the best assistance I know for comprehending the nature of the complex derangements of which every special disease is ultimately composed. To trace back, therefore, any given disease, only so far as to identify it with the nosological exemplar, and to make this the point from which to commence the minute examination of the morbid condition, leaves a most essential, and by far the most instructive part of the enquiry unperformed. The scrutiny of an individual malady can never be complete when it only commences with a stage of disease already advanced; and the employment of remedies must ever fail in precision, and can make but slow progress towards the perfection attainable, so long as the mode obtains of first judging the disease by its correspondence with a nosological character, and then applying to it the means which have proved serviceable in the larger proportion of similar cases. Whether we regard the exposition of disease, or the adaptation of remedies, this mode is imperfect and objectionable. No individual disease corresponds exactly with the nosological prototype; each has its individual character, involving more or less peculiarity to distinguish it from every other; and it continually happens that a scrutiny of this peculiarity furnishes the main guidance to successful treatment. ​
I wish not, by any means, to decry nosology. It has its use, and may even be regarded as absolutely necessary. But, while it has contributed, in some respects, to the advancement of medical science, it has, through misapplication, done much also to retard it. It is, at length, full time, in profiting by the good, to avoid the evil. Reference to nosology is of use, in directing attention promptly to the more important lesions, so as to ascertain what organs or functions are principally suffering. But much more is required even when this point is decided. The only mode practically valuable of scrutinizing an individual disease is, not to aim at identifying it with the nosological exemplar, but to ascertain the several functions actually depraved, making health the standard by which to judge of the nature and extent of the respective derangements. The functions of life are not very many, and the healthy condition of each is, or ought to be, well known. There is no difficulty in scrutinizing each function, so as to ascertain whether it be healthfully performed, that is, with a vigour adequate to its efficient exercise, yet not verging on excess. Yet, in this respect, the prevailing notions are much less correct than they ought to be, and numbers are daily regarded as in perfect health, who, on a very slight examination, would shew evidences of such derangement of function, as only awaited an adequate exciting cause to be aroused into disease of the most intense activity. The habit too much obtains of ascribing the degree of severity of disease to the activity of the exciting cause. Much more truly would it be imputed to the state of constitution to which the exciting cause is ​applied. Whence comes it that from any given exposure to an exciting cause, no two persons will be affected alike, or in the same degree? Some may suffer severely, others be slightly affected, while by far the greater number will escape altogether. This simple fact of familiar occurrence might have sufficed to direct a greater share of attention to the predisposition, on which exciting causes operate. Of the prevailing error, the mischief is two-fold, for, in attributing an undue importance to an exciting cause, it assumes a principle which can be of very little avail in directing the treatment, while, on recovery, it begets further error, by inducing a greater solicitude to avoid the exciting cause, than to keep the constitution in that healthful state which would prove the best preservative.
Ordinary maladies, however suddenly the parties may appear to be seized, are never of sudden occurrence. The special suffering which first arrests attention may suddenly arise, but this is always preceded, and for a considerable time, by sensible deviations from that equable and temperate performance of function which can alone constitute sound health. The common exciting causes to which so many of our ordinary maladies are imputed, and from which they doubtless in part arise, never produce their effects save on constitutions prepared to suffer by their influence. The instances of disease from morbid poisons, such as contagions, miasmata, and such like, may appear exceptions; but they are really not so. All who are so exposed do not suffer, and in those who become affected, the degree of suffering is dependant less on the intensity of the ​exciting cause, than on the deprivation of habit, which unfits the natural powers for resisting the morbific influence.
Health being the standard by which alone disease should, according to the mode of enquiry now advocated, be judged, it is essential that what constitutes health should be clearly understood. In this no ambiguity should be suffered to prevail, nor should appearances be trusted to. Florid looks, energy of frame, buoyancy of spirits, are no criterion, and may be deceptive, for all these may co-exist for a time with a state of constitution, which, if not amounting to disease, is fast approaching it; a deeper scrutiny is necessary for verifying the alleged health which such persons are supposed to enjoy. To substantiate this, every function of the frame should be shewn to be in healthful exercise, neither wanting in power, nor too energetic, and to this end each should be separately examined. A state of health requires a calm pulse, temperate skin, clean and moist tongue, a clear head, tranquil respiration, natural appetite with digestion unconsciously performed, regular bowels, all the several secretions and excretions in adequate quantity and of natural character, and, finally, sound repose. If, in any of these respects, material deviation be discoverable, then, however unconscious the party may be of the existing derangement, health is so far impaired, and more determinate disease will sooner or later be sure to ensue. It may not be amiss to notice here some of the derangements most apt to be misconceived or disregarded. The pulse, which is the principal index of the sufficiency of the nutritive matter imbibed ​into the system, and of the powers by which it is appropriated to the purposes of the economy, continually misleads; so prevalent is redundancy of blood, and the energetic circulation to which it gives rise, that a pulse of perfect health is rarely met with. The standard of force, by which most people judge of a healthy pulse, is much too high. The pulse of real health is singularly calm, soft, equal, compressible, conveying no impression of a stream labouring in its course, nor of an energetic propelling power. Many misconceive it as a pulse of debility, and, on the slightest indisposition, enjoin, on this ground alone, more nutritive diet, wine, and stimulants, in order to restore that vigour in which they deem the pulse deficient, quaintly assuring the parties that they are a cup too low. The counsel is palatable, and its early effects are well calculated to confirm both parties in their error. Truth, however, cannot be thus altered, and from those who sincerely seek it, it need not be long veiled. What is ordinarily regarded as a pulse of health, should much rather be deemed that of incipient plethora. When this commences, when in a healthy frame the balance of nutritive matter in the system inclines to excess, the earlier effects are, increased nutrition, a greater vigour in the several functions, a more florid aspect, in short, a series of changes which, collectively, seem to mark only an exuberance of health; and, up to this period it must be confessed, that no actual disease is present. But this stage is of limited duration. The excited powers are incapable of sustaining the overstrained exertion, and a stage of enfeebled power next ensues. The pulse, hitherto ​full and strong, becomes feebler and somewhat irregular. On careful examination by a practised finger, the irregularity will be found to affect both the frequency, the rhythm, and the force; other derangements of frame accompany this stage, but my present purpose is with the pulse alone. This enfeebled and irregular pulse is continually misconceived as indicative of debility, and stimulants are resorted to for arousing its dormant powers, when depletion and abstinence would be the more rational treatment.
These few representations may suffice to shew, that sensible derangement of frame, cognizable by the pulse, may exist, while the party is yet unconscious of being otherwise than in perfect health. Should such a person be suddenly seized with some acute distemper, from exposure to an exciting cause, it is obvious that the antecedent state of general health must have material influence on the superinduced disease. Depravation of other functions may also escape notice, if appearances be relied on, or superficial examination trusted to. The brain may be overcharged with blood, giving rise to casual languor, drowsiness, heavy sleep; the heart and lungs may labour from slight bodily exertion; the stomach may feel oppressed by food; the tongue may be white and furred; the stools inadequate, or dark, slimy, and fetid; the urine turbid, and throwing down a copious sediment, yet, notwithstanding these unequivocal manifestations of disturbed health, if no special lesion impede the course of life, if the party, incited by adequate cordials, be capable of going through the day's engagements, the consciousness ​of health may continue uninterrupted, and the reality of its existence be void of suspicion. If, in this state, too, through any exciting cause, an acute accession of disease arise, this will be regarded as of sudden occurrence, and the exciting cause will be exclusively blamed. Medical reasoning, in this respect, needs some correction, and practitioners are called on to pay more attention than they have hitherto done to incipient disease. The investigation will amply repay them, not only in the greater power which it will give for employing with effect prophylactic treatment, but in the light which an intimate knowledge of incipient disease cannot fail to shed on the more advanced and more complicated stages.
On the present occasion it is my desire to be brief. Where hints suffice, elaborate discussion would be impertinent. The few which I have offered are, I trust, not unworthy the attention of those to whom they are addressed; and it would be a gratification to me if further illustrations were now to come from other hands. It remains only to offer a few remarks on the employment of remedies. The practice of physic may, according to the intellect, cultivation, and moral qualities of the individual pursuing it, be regarded as a science, an art, or a trade. So obvious is the application of the terms, that they need no explanation. The latter distinction was long ago made by a shrewd observer of human nature and the world. Swift, who, in a gloomy fit, laments, among other desolation's, his being
" Deprived of kind Arbuthnot's aid.  Who knew his art, but not his trade."
requires but little skill, the qualities best suited for ensuring a prosperous career having no necessary connexion with intellect or science; an imposing manner, confident pretension, verbose declamation, interlarded with high-sounding terms, no matter how unintelligible or unmeaning; unhesitating assurances of cure; condemnation of whatever antecedent practitioners had done; these, and various other still less worthy arts, will suffice to gain a reputation sufficient to satisfy the cupidity of whoever can descend so low as to resort to them. It is ignorance only that can be thus misled; and, unhappily, this ignorance in all that regards the well-being of the body, and the maintenance or restoration of health, pervades all classes of the community to the highest. Strange! that while every other branch of knowledge is studied with increasing assiduity, and becoming daily more widely diffused, even the most intellectual classes of society are content to remain in utter ignorance of the mechanism and functions of their own frames. They are hence the ready dupes of every impostor, being wholly incapable of forming any just estimate of medical talent. Happy will it be for the legitimate sons of science, when a knowledge of the animal economy becomes so appreciated as to constitute a necessary branch of liberal education. Then, and not before, will genuine science and sound talent find their proper level; then will science be cultivated with more steady and effective zeal, the encouragement of just appreciation being necessary for the support of those who labour for its advancement. ​
The following passage in the last Edinburgh Review, as evidence of the public ignorance just alluded to, is so apposite that I am tempted to quote it. It occurs in the article on Dr. Thompson's life of Cullen, p. 462. “Of all subjects of scientific interest, men, in general, seem to have the weakest curiosity in regard to the structure and functions of their own bodies. So it is now, and, however marvellous, so it has ever been. 'Eunt homines,' says St. Austen, 'mirari alta montium, ingentes fluctus maris, altissimos lapsus fluminum, oceani ambitum et gyros siderum,─seipsos relinquunt, nec mirantur' For one amateur physiologist, we meet a hundred dilettanti chemists, and botanists, and mineralogists, and geologists. Even medical men themselves, are, in general, equally careless and incompetent judges as the public at large, of all high accomplishments in their profession. Medicine they cultivate not as a science, but a trade; are indifferent to all that transcends the sphere of vulgar practice, and affect to despise what they are unable to appreciate.” Let us hope that the latter part of this pasquinade only shews the ignorance of the reviewer, and that it does not truly characterize the profession. Some ground for the imputation there may be, but, if so, it results not from the general profession being liable to such a charge, but from its best energies being repressed and obscured by the manifold disadvantages under which it labours. Such is the public ignorance of professional merits, that individuals acquire a prominence which, in a more enlightened state of the public intellect, they could never attain. These bring discredit on a profession which, if its ​voice were to prevail, would never depute them its representatives. Professional merit is, no doubt, in many instances, patronised by the public; but the estimate is accidental, for they who decide are no adequate judges. But, if the reproach thus cast by the reviewer attach at all to the profession so generally as is asserted, the fault would still lie not with the profession, but with those who, by upholding ignorance and impudence, confound all distinctions, and take from merit its legitimate encouragement and support. The utter incapability of the public to form any just estimate of medical talent, acts as a positive discouragement to all laborious and enlightened research; and they who feel this depressing influence, if it were to extinguish their zeal, (for that it does I confidently deny), would have ample excuse, and would be entitled to every indulgence were they, in weariness of spirit, to exclaim, if it happeneth to the fool even as unto us, why should we labour to be more wise? The sarcasm of the reviewer, as applied to the general profession, I believe to be unmerited: and if merited, it would still be unjust, inasmuch as the blame would lie not with them, but in the public ignorance of all physiological knowledge, and also in the political constitution of their own department, which makes no provision for distinguishing those whom the profession itself would delight to honour. The highest honours of physic are allotted not by superiority of merit, but by accident of education, and consequently collegiate rank is no measure of talents or acquirements; at least, none of the estimate which the profession itself forms in these respects. Let eminent station be the meed ​of superior merit only; let that meed be awarded by those who can best appreciate the merits and whose delight it would be so to distinguish it, namely, the profession itself; the highest places would then be filled by those best fitted to adorn them, and an incitement be given to the whole body, which would soon remove every shadow of such reproach as the reviewer has cast on them.
This notice of the trade of physic is rather a digression, and somewhat out of place. It was wholly unpremeditated; association with other thoughts brought the subject unbidden to my mind, whence it flowed reluctantly to my pen. Having no application to those whom I now address, it might be expunged, and should be so, were it not that it presents some truths which appear to me to merit grave attention. The imputation, too, so broadly cast on the profession, seemed to call for some disclaimer, and, feeble as mine is, I could not withhold it, as evidence that the profession is not so degraded as the reviewer represents; that it is not wholly absorbed by considerations of mere trade; and to shew that its aspirations are extended somewhat beyond the sphere of vulgar practice, I might appropriately refer to the almost simultaneous and widely pervading zeal which has, on the call of a single voice, so promptly formed the Association which gives occasion for this essay. The instance suffices to prove, that zeal for the higher objects of medical research is not deficient, and that, amid all the anxious cares of life, medical men are ever ready with their best efforts to promote all the higher and more dignified objects connected with their profession. As an art, guided in its exercise by the ​principles which science supplies, physic is a noble vocation, calling forth the highest powers of the intellect, the purest emotions of the heart, and all who feel interested in its reputation, must be gratified and elevated in reflecting that, as such is it at the present day, cultivated by a body of practitioners who may vie with any other class of the community in sound judgment, extensive cultivation, varied knowledge, liberal principles, and active benevolence.
But to return to the more immediate purpose of this brief essay: physic, practised as an art, employs its remedies according as they produce effect, either immediately on the physiological functions of the frame, or more remotely on the morbid actions which constitute the disease. The operation of remedies, therefore, may be conveniently distinguished as physiological, or curative, the distinction applying, however, not to the actual operation of the remedies, for this is always physiological, but to our perception of their effect, which in too many instances fails to trace, from the primary impression made by a remedy, the consecutive physiological changes through which the curative effect is produced. It is this distinction which constitutes the difference between what have been called rational and empirical practice; the former applying remedies immediately according to their physiological operation, with a more remote view to their curative effect, the latter regarding the curative effect alone, and taking no account of the intermediate functional energies by which the cure is accomplished. Owing to the imperfect state of our knowledge, the treatment of disease ordinarily pursued by judicious practitioners, partakes of both ​kinds; it is rational so far as the curative effect is sought through a primary influence on some or other of the natural functions followed by consecutive changes thence resulting; empirical, when from obscurity in the modus operandi, and failure in discerning the series of vital actions through which the cure takes place, this the ultimate effect can be alone perceived. Blood-letting, when employed for relief of diseases occasioned by plethora or congestion, may serve as an instance of the former; the use of bark in stopping a paroxysm of intermittent fever, will exemplify the latter. The enlightened practitioner will, so far as science and experience can guide him, lean to the use of the former class of remedies as most intelligible in their operation, more manageable under varying circumstances, and, on these accounts, more certain in their results; but he will not despise the aid of empirical means for doing whatever good they may be able to accomplish.
It is clear that, if, in the operation of remedies which, through our ignorance, we are compelled to use empirically, we could discover the series of physiological changes through which the curative effect is produced, our knowledge would be most valuably extended, and our capability of administering such remedies with precision and certainty, be greatly increased. And this suggests one course of medical enquiry, worthy the attention of every cultivator of the science, and which will not be speedily exhausted, namely, to ascertain the primary impression and consecutive functional changes through which each remedy, employed for the cure of disease, acts, ultimately, on the pathological derangements for which ​it is administered. To say that a remedy cures a disease, and to be content with this knowledge, would betray a lamentable misconception of what medical science requires. The fact is always valuable, but, to be fully available, we should have some insight into the modus operandi, else we must be ill prepared to regulate those circumstances by which the operation of the remedy would be advanced or impeded. It continually happens that a remedy proves effectual, or the contrary, solely through the mode in which it is administered, whence it is often less the quid than the quomodo that is of importance. Ample are our remedial resources both in number and power, if we knew but rightly how to employ them. This knowledge must be sought through a closer investigation of those vital processes by which nature, when duly assisted, can accomplish so much in rectifying the derangements of the animal frame. It will not be denied that many such operations of nature, which at present lie hid, are capable of being discovered; and, if so, the medical enquirer can hardly pursue any research more useful or interesting than that of exploring them. Some valuable remarks "concerning the action of medicinal substances on the living system," may be seen in a small but interesting volume published by Dr. Spillan, of Dublin, entitled "a Supplement to the Pharmacopoeias".
In determining the treatment of diseases, no mode can have less to recommend it than that which adapts the remedy according to the name of the disease. And yet it is very prevalent; even intelligent practitioners being sedulous to ascertain from medical records, what course of treatment has most ​generally succeeded, in order to apply it in some particular instance. This kind of knowledge, too, is the staple of all works known by the name of Practice of Physic, than which none can be less satisfactory for consulting when difficulties occur, for although they exhibit, even to redundancy, means by which cures have been effected, they fail to display, sufficiently for guiding the practitioner, the grounds on which a choice should be made, or the minute observances essential for administering any remedy with effect. Such knowledge as they impart, is, no doubt, useful and necessary, but it furnishes no certain guidance. The treatment most generally successful may have been deduced from an extensive examination of cases faithfully and accurately recorded, and yet it may be wholly inadmissible in the particular instance in which its application is contemplated. As was before remarked, the only security against error lies in adapting the remedies not according to the name given to the disease, nor to the alleged success of former cases, but to the special derangements which prevail in the several functions of the individual frame under consideration. The more nearly the treatment of diseases can be brought throughout to this degree of accuracy, the more scientific will the art of physic become, and the tendency of all medical observation and of all medical writing, should be to advance in this direction. Medical observation is ever incomplete, unless it take cognizance of all the functions, the aggregate adequateness of which, respectively ascertained, constitutes and is essential to health. The state of each should be accurately examined, however unconnected ​it may appear to be with the prominent derangement. Diligent scrutiny will often detect a morbid condition where it was unsuspected; and a negative should never rest on surmise wherever direct evidence is attainable. Even where a regular consecutive train of morbid actions cannot be traced from the primary disturbance to the more remote consequence, morbid sympathies (a term which merely implies our ignorance of the intervening links in the chain of causation), will be found oftentimes to exist, which connect many painful affections with distant and often unheeded irritations. Enlightened scrutiny may frequently detect the latter when, from superficial examination, they had been overlooked. Darwin, in a case of convulsions, traced the source of irritation by which the nervous system was disturbed, to a ragged and inflamed wart, by the removal of which the disease was cured. The instances are of daily occurrence, in which remote excitements are caused or aggravated by the irritation derived from disordered bowels. If such diseases be treated with reference to the remote excitement only, in other words, to the ostensible nosological disease, a cure is hopeless, or, at best, tedious and uncertain, while, by removing the cause, they readily yield. And this suggests the absolute necessity of attending closely to the state of the bowels in all diseases, be the special malady what it may. Adequate stools, with healthy intestinal secretions, are necessary at all times. They become doubly so whenever the general health is disturbed, or disease of any kind has occurred. A large proportion of disease presents more or less of a febrile ​character. In all such, the intestinal secretions become first increased, then vitiated. This vitiated matter accumulates, inflicting a two-fold injury, both obstructing the secerning vessels in the exercise of their functions, and acting itself as an irritant in producing or aggravating manifold distant disturbances. If the stools, and especially those which detergent purgatives evacuate, be duly inspected, they will supply ample evidence of the vitiated secretions here referred to, and furnish much valuable guidance both in the choice of purgatives, and in limiting their salutary use. In no class of remedies is accurate administration more important than in that of aperients. Remedies of this class act in various ways; they carry forward the ordinary contents of the bowels; or they excite the exhalents producing watery evacuations; or they cause the mucous membrane to throw off its redundant secretions. According as either operation is needed, should the special aperient be adapted. So connected is a disordered state of the intestinal canal with most diseases, whether as cause or effect, that its precise condition, as evidenced by the stools, cannot be too accurately noted in reports of medical treatment. Much benefit has resulted from the greater attention directed to the state of the bowels, by Dr. Hamilton and Mr. Abernethy, both of whom have ably advocated the free evacuation of the alimentary canal. Both, however, fail to connect the disordered condition of bowels with the previous state of health, and so far leave the pathology of the diseases of which they treat, defective. Mr. Abernethy errs in tracing diseases to a disordered state ​of the chylopoietic viscera as the primary irritation, overlooking that this disordered state must itself have had a cause. If his attention had not been absorbed by an engrossing conception, he must have perceived that this derangement of digestive function arose itself from other disturbing causes equally capable of detection; that in many instances it had its origin in overcharged blood-vessels excited to morbid actions, and endeavouring to relieve themselves by increased activity in their secretory and excretory functions; and that in such cases moderate blood-letting, in aid of his blue pill and alkalised bitters, would effect, both more speedily and more perfectly, the restoration of healthy secretion which he was so anxious to promote.
In many respects the effects of remedies should be more accurately noted than is generally deemed necessary. Many report the curative effects of blood-letting, without noticing the character of the blood drawn. This omission is hardly excusable. Even the ordinary account of blood being sizy, buffed, or cupped, is too meagre. Many other variations of condition exist, as must be well known to all who closely examine. In ascertaining the condition of the coagulum, simple inspection is not enough. Division of the mass with a scissors, will best exhibit its real state, and will, occasionally, display what would not otherwise be suspected. In this way irregular masses of gluten will be sometimes found dipping into the subjacent cruor. The thickness and firmness of the buffy coat, too, can only be thus shewn. Even the fact of burliness may be thus ascertained, when it would otherwise be overlooked. It ​continually occurs, though the fact seems not to have been noticed, that a thin but firm buff, of a pink colour, presents, on slight inspection, an appearance as if no buff were formed. The shades of colour vary, yet are all such as to convey to those who are unaware of the fact, the impression of there being no buff. Yet, if the coagulum be cut through, the buff will be found well defined, and sufficiently firm to support, on a probe passed beneath it, the whole coagulum, the dark portion of this being of the usual loose texture.
The condition of the urine, too, demands more careful notice than it generally receives. In dropsical affections it promises to throw much light on the pathological state, and to furnish useful guidance in the exhibition of remedies. Dr. Bright has ably traced a connexion between coagulable urine and certain organic derangements of the kidneys; and his remarks have been amply confirmed by other eminent practitioners. There is reason to believe that functional disturbance alone of the kidneys may produce albuminous urine. These cases are inflammatory; the albumen is much more abundant than in those noticed by Dr. Bright; it varies with the progress of the disease, and disappears as this retires. In the progress of treatment, too, it furnishes valuable guidance for the due administration of remedies, such as no other indications yield. The object of treatment in all diseases, is to excite the constitutional powers to sanative efforts, just so far as is necessary for remedying the existing derangement. To carry the excitement beyond this point, is to waste power and do mischief. This is well ​exemplified in dropsy. Mercury, used to a certain extent, corrects the vascular action which produces effusion, promoting also the absorption of what is effused. Carried beyond this, it may break down power and counteract all the good effected. A criterion by which to judge of its adequate administration, so as to avoid its excessive use, must here be valuable. For this the ordinary evidences of mercurial action are insufficient. The state of the urine, when albuminous, supplies a test of much value. The albumen will gradually diminish, and finally disappear under the use of mercury; but a prolonged use of this is liable to reproduce the albumen. Here the urine furnishes the only test by which to judge. I have seen the urine cleared of albumen, the subsidence of dropsy keeping pace with its decline. Anxious to accelerate or to keep the ground gained, I have, in such case, resorted again to mercury, but, with the effect of the albumen returning. The mercury was withdrawn, the albumen again ceased to appear. That the guidance here afforded by the urine was most salutary, I have no doubt, and I know of no indication, save that supplied by the urine, that could have afforded it. The specific gravity of urine, too, seems worthy of being ascertained, wherever the existing disease involves a morbid condition of this excretion.
It would be easy to pursue these remarks in more extended and minute detail, but enough, I conceive, has been stated, to shew the kind of scrutiny which both morbid actions and the operation of remedies should receive, in order to render medical reports available for the guidance of the practitioner. Without ​advocating a tedious minuteness in the specification of symptoms, I would consider it expedient that the condition of every important function of the frame should be clearly and distinctly stated; in short, that all should be told into which the observer himself deems it necessary to enquire, or which has any influence in directing his own judgment. Every practitioner of experience must know that circumstances apparently trivial enter largely into his considerations, whether of the diagnosis, prognosis, or treatment of disease; and whatever is thus influential, however slightly in degree, it is of importance to record. I ought, perhaps, to notice specially the morbid appearances of the tongue and of the countenance, so various, and so expressive of much which the functions more generally examined may fail to indicate. The importance of the indications which they furnish, and the assistance which they render in the attainment of an accurate diagnosis, is admirably illustrated by Dr. Marshall Hall, in his “ Commentaries on some of the more important diseases of females.”
The task which I assigned myself is now performed. It sprung from the sense which I entertain of the duty incumbent on every member of the newly formed association, of contributing with his best powers to the ends designed. If the suggestions offered in the preceding pages merit but slight estimation, they will, at least, occupy but little space in the forthcoming volume. Should they, on the contrary, be deemed not wholly unimportant, the subject cannot fail to interest others, so as to ensure its being more worthily and more ably treated.