CONTENTS.
CHAPTER I.
UNCERTAINTY OF MEDICINE,
Importance of the subject. Definiteness of results in chemistry. Only a distant and humble approach to this possible in medicine. Illustration from chemistry. Causes of the Uncertainty of Medicine. 1. Sympathy between different organs; 2. Symptoms produced at a distance from the seat of disease. Disease extended by sympathy. Transposition of disease from one organ to another. 2. Influence of unseen or secret causes. Nature of many causes of disease unknown. Combination of many agencies in producing disease, some of them having acted a long time. Cases rendered complex by treatment before physician is applied to. 3. Natural changes in the system arising from the curative power of nature, and from the principle of self-limitation in diseases. Illustrations of the operation of the vis medicatrix naturæ—vomiting to remove offending matters from the stomach—suppuration and discharge of a swelling. Tendency of diseases to come to a conclusion—more definite and regular in some complaints than in others. Mistakes from confounding the effects of remedies with the changes produced by these two tendencies. 4. Mental influences. Connection of mind with body modifying disease. Effects produced through the mind often attributed to physical causes and remedies. Case of the dyspeptic. 5. Individual peculiarities.
CHAPTER II.
SKILL IN MEDICINE,
Show in what medical skill consists, in view of the uncertainty of medicine—appreciating the condition of the patient in all respects, and applying remedies in the best manner to relieve this condition. Errors impairing skill. Taking limited views of disease. Directing attention too much to particular organs. Undue attachment to certain modes of investigation. Difficulties in the way of deciding what it is best to do. Course of different physicians in view of these difficulties. Accurate proportioning of means and ends. Value of experience. Illustration of some of these points in the case of a sick traveller assisted by his friend in going through a mountain pass.
CHAPTER III.
POPULAR ERRORS,
False estimate of the importance of positive medication. This error appears in various ways. Healing of wounds—anointed axe. Attributing effects to agencies just preceding them—post hoc propter hoc mode of reasoning. Referring the cure of a case to some one remedy or measure, when commonly the result of many. Disposition to have something done all the time. Disease considered often as a palpable thing—a humor—a poison—medicines supposed to neutralize it. Specifics. Supposed to be many—really few, if any. Definition. Inadequate ideas of the community of the necessity for discrimination in medical practice. Propensity to look for some universal catholicon. Disease supposed by some to be an unit. A sort of universality of operation attributed to favorite remedies, even sometimes among physicians. Dr. Beddoes’ gases. Physicians correct their errors by experience—the public only exchange one error for another in medicine. Changes in popular opinion in regard to quack remedies.
CHAPTER IV.
QUACKERY,
The grand source of quackery the false reference of effects to causes. The way in which a remedy, whether active or inert, acquires its reputation. Quack medicines principally of three kinds. 1. Evacuants. Great similarity in these—made up mostly of articles in common use. 2. Those which are supposed to act upon the system in a gradual way, as alternatives. Preparations of sarsaparilla. Impositions. 3. Those which are supposed to act especially upon the lungs. Harm done by their indiscriminate use. Quantities of inert and damaged articles used in preparing quack medicines. Importance of the name of a medicine in giving it currency. Ridiculousness of quack advertisements. Certificates. Chiefly of four kinds. 1. Forgeries. 2. Essentially, sometimes wholly, untrue. How obtained. 3. Those given by invalids imagining themselves to be relieved. 4. Those given by invalids who are relieved while taking the medicine—inferred to be done by the medicine. Certificates of clergymen. Rule of the medical profession in regard to nostrums. Proposed mode of guarding against imposition. Quackery as a monstrous business interest. Press and legislatures trammelled by it. Itinerant quack lecturers. Lectures especially to the ladies. Animal magnetism. Paracelsus the “prince of quacks.” St. John Long. Perkins’ tractors. Forms of Quackery many, but the materials from which they are formed always the same. No discoveries have ever been made by quackery.
CHAPTER V.
THOMPSONISM,
Principles of the system as promulgated by its founder. Bold confidence of Thompson in his mode of practice. Points in his theory. Obstructed perspiration. Strife between the heat and the cold. Simplicity of the system. No need of “learned doctors.” Thompsonian views of the modus operandi of medicines. Radicalism of Thompsonism. Prejudice against mineral medicines. No article injurious simply because it is mineral. The most deadly poisons in nature vegetable. Effects of vegetable poisons generally as abiding as those of mineral. Lobelia a poison, sometimes fatal, though Thompsonians claim it to be perfectly harmless. Definition of poison. Some poisons more rapid than others in their effects. Poison sometimes used in a relative sense. This word one of the watch-words of Thompsonians, though they daily use poisons as common articles of food. Changes in Thompsonian practice since the system was first promulgated.
CHAPTER VI.
HOMŒOPATHY,
Brief notice of the founder of Homœopathy. His exalted ideas of his “discovery.” Two principles in his theory. 1. Like cures like. According to Hahneman there are three modes of practice—allopathic, antipathic, homœopathic. The last alone truly successful, according to him. The name allopath wrongly bestowed by Hahneman upon physicians. 2. Minute division, with agitation and trituration, communicates a new power to medicines. Subdivision very minute, and extremely particular directions given by Hahneman for effecting it. Whether such a power is thus communicated to be decided by facts. “Observations” on which the opinion is founded. Character of them illustrated from Jahr’s manual. Their extreme minuteness. Mode of collecting them. Based upon the ridiculous idea that all states of the body are to be referred to the remedy taken. Notices of some particular remedies in illustration. Alleged success of Homœopathy. Apparent success to be attributed to six causes. 1. Mental influence. 2. A strict regard to diet and regimen. 3. Operation of the vis medicatrix naturæ, or curative power of nature. 4. Comparisons made between the results of homœopathic practice and those of over-dosing physicians. 5. An occasional stealthy use of remedies in ordinary doses. 6. The facility with which people are deceived in regard to comparative results. Parallel case of a German clergyman. Empty boasts of homœopathists as to the character of their physicians. Points of resemblance and of difference between Thompsonism and Homœopathy.
CHAPTER VII.
NATURAL BONE-SETTERS,
Setting of bones wholly mechanical. There cannot be an innate skill in this, any more than there can be in any other kind of mechanics. Explanation of bone-setting. Skill obtained in this just as in anything else. Bone-setter learns all that he actually knows, by his own observation, and from others. It is not born with him. Gets some of his knowledge by stealth. Errors committed by natural bone-setters. Supposing a fracture to be a dislocation. Injuries of joints in which there is neither dislocation nor fracture—harm sometimes done in such cases by the bone-setter. Failure in the medical part of the treatment in some cases. Failure in the management of fractures. Physicians not all good bone-setters. Mechanical tact requisite. Though so many cases of mal-practice can be found among the patients of natural bone-setters, generally supposed by the community to be infallible. Difficulty in getting a verdict of damages against them. Reasons why they, in spite of their errors, acquire a reputation for skill. Setting sprains. Facility of the imposition practised. Breaking up old adhesions. Stiff joints and contracted tendons—efficacy of rubbing. Imagined tenderness and inability of motion. Sub-luxations—random pulling. False reports of cases.
CHAPTER VIII.
GOOD AND BAD PRACTICE,
Not easy to distinguish between good and bad practice by results. If it were, would not be such differences of opinion among physicians and in the community. Examples of these differences. Stimulating and depleting measures. Homœopathy, Hydropathy, Thompsonism. Quacks aware of the difficulty in estimating comparative results—act accordingly. No mode of practice wholly good—none wholly bad. Some good points in all modes. Exclusive systems. Distinctions between good and bad practice pointed out. Cases in which the question of life and death immediately affected by practice. Failure of unskilfulness in such cases. Interesting case. Seldom is the influence of bad practice so manifest as in this case. Difficulty of culling out from the mass cases which are dangerous from the first. Various causes of this. Difficulty inherent. Cases misrepresented by mistake or wilfully. Some said to be very sick when not so. Light cases made bad by treatment—though appear grave, apt to recover. Illustrations. Comparisons between rival physicians as to results. Public often mistake in such comparisons. Notice some less direct effects of bad practice. Unnecessary complications of disease. State of system after recovery. General state of health in families. Length of sickness. Summing up of differences in results between good and bad practice. Two requisites for observing these correctly. 1. Sufficient amount of evidence. 2. Skill in observation. Community deficient in these. Confident appeals of quacks to alleged results. Show what the physician should say in regard to results.
CHAPTER IX.
THEORY AND OBSERVATION,
All real knowledge based upon observation, not on theory. Facts of two kinds—individual and general. General facts ascertained by observation of many individual or particular facts. No theory founded on facts—always goes beyond them. No science in which there has been so much theorizing as in medicine. History of medicine very much a history of theories. Office of theory—suggestive. Abuse of theory in failing to distinguish between the known and the supposed. Newton’s carefulness on this point. Circumstances impairing skill in observation. Mode of reviewing cases. Disposition to form conclusions from a limited range of facts. Young practitioners. Dr. Sewall’s plates. Dr. Sutton’s treatment of delirium tremens. Different theories of fever—Boerhaave, Cullen, Clutterbuck, Broussais, Cooke, Samuel Thompson. Hobby-riding. Diseases of the throat and windpipe. Habit of making loose and exaggerated statements. Credulity and fondness for novelty and change. Changeable state of medicine. No standard authorities as in law and theology. Scepticism in medicine. Easy to theorize—difficult to observe well. Value of good habits of observation. Medical men had too much to do with theories and modes and systems. Eclecticism. Modus operandi of medicines. A reform in progress in medicine. Breaking loose from theory. Promoting rigid observation.
CHAPTER X.
POPULAR ESTIMATES OF PHYSICIANS,
No class of men so erroneously estimated as physicians. Object of this chapter to show how the community can judge of them correctly. Education of physicians—evidences of it. Medical education practically despised by a large portion of the public. Standing of medical man among his brethren criterion of merit. Difficulty in getting their unbiased opinions. Certain mental qualities essential to skill in the practice of medicine. How the common observer can detect and measure these qualities. Observe them as exhibited in regard to subjects which he understands in common with the physician. Illustration from surgery. Illustrations of same truth in relation to various characteristics of medical men. Formation of opinions—credulous—sceptical—hasty and changeable—cautious and tenacious—strong and ardent. How can test one’s habits of observation. Asking many questions no sure proof of accurate and minute observation. Enquiries of different physicians about an article of curiosity. Same rule for judging of the measures of the physician, as we have applied to his opinions. A genius in medicine. Innate skill. Rules which have been pointed out for estimating comparative merits of physicians not in common use with the public. A change necessary in this respect. Cannot easily be effected. Many physicians would be opposed to such a change—would rather false tests continue to be applied. But the change can be effected.
CHAPTER XI.
MEANS OF REMOVING QUACKERY,
The credulous, ignorant, and novelty-seeking, not the only persons imposed upon by quackery. Many of the judicious and intelligent also. Efforts to undeceive the public on this subject have been often faulty. Too much reliance on popular knowledge of anatomy, physiology, dietetics, &c. This should only be auxiliary to other means. Relied upon alone, leads to error. Individual influence of physicians in showing their friends their mistakes in connecting cause and effect in medicine. This influence to be exerted upon the intelligent who uphold quackery. Too much sarcasm and ridicule and invective used against quackery. Credulity of the public takes a license from that of medical men. Certificates of physicians in favor of nostrums. Secret medicines put forth by physicians. Spirit of quackery in the medical profession. Exhibited in various ways. Quite prevalent, crippling the profession in its warfare with empiricism. Reform needed. Can be effected. The stable and intelligent can help in effecting it, by promoting medical education—by sustaining the organizations of the profession—by renouncing fallacious means of estimating professional merit—by favoring strict observance of the rules of intercourse among physicians. Formation of the American Medical Association, an important movement in the destruction of quackery.
CHAPTER XII.
INTERCOURSE OF PHYSICIANS,
Erroneous views in regard to consultations. “Jury of doctors.” Dictation not consultation. Giving opinions in relation to the past treatment. Offices of the consulting, and of the attending physician defined. Freedom in consultation necessary. Between enemies, useless. Should be alone in consultation. Intrigues of dishonorable practitioners. Supposed want of agreement—favoring the impression for base purposes. Attributing changes, good or bad, to some remedy for selfish ends. Failing to defend a medical brother when circumstances fairly demand it. Making comparisons between cases. Undue attentions to the patients of others. Conduct of some when called to see the patient of another in case of unnecessary alarm. Physicians supposed to be too much attached to etiquette. Not so usually. Differences and quarrels of physicians—circumstances giving rise to them. Facility with which deception is practised in medicine. Peculiar relation of the physician to his employers. Cliques. Sectarian and other associations. Avoiding quarrels. Relations of elder physicians to their brethren.
CHAPTER XIII.
INTERFERENCE WITH PHYSICIANS,
Confidence which one feels in his physician no reason for disparaging others. Interference proper in some cases—quackery—gross ignorance—intemperance. Reckless attacks upon professional character. The lawyer rebuked. Free canvassing of the merits of physicians not improper. Interference in the sick room. Destroying confidence. Recommending medicines. Restricting physicians as to remedies employed. Frequency of physician’s visits to be mostly left to him. Anxiety of friends of the sick often embarrasses the physician. Case of the wife of Napoleon. Harrassing practitioner with inquiries and criticising his practice distract his attention, and therefore foil his skill. Same effect produced by the same causes in regard to other subjects. Criticised clergyman. Watched juggler. Defects in these analogies.
CHAPTER XIV.
MUTUAL INFLUENCE OF MIND AND BODY IN DISEASE,
Inadequate views of this influence prevalent. Importance of understanding it. Connection of mind and body. No proof that mind is essentially indestructible. Manifestations of mind connected with and dependent upon the material organization. Brain in some sense seat of mind—central organ of the nervous system, with which mind is connected. Other subordinate nervous centres. Bichat’s idea of the seat of the moral sentiments. Weakness of mind in sickness. Slight causes affect it strongly. Importance of quiet in sick room. Difficult to secure it. Visitors. Conversation. Children as easily disturbed as adults. Holding up physician as a bugbear to them. Exciting the mind commonly irritates bodily disease, whether in the brain, or in some other organ. Death of Hunter caused by a fit of passion. Duty of physician sometimes to excite the mind in various ways and degrees. Influence of imagination upon the body. Use to be made of mental association in the treatment of disease. Diversion of the mind. Influence of change of scene on the invalid. Monotony of sick room. Settled gloom with which the sick sometimes afflicted. How removed. Want of tact in managing whims of the sick. Notional dislikes. Fretfulness and impatience. Deranged sensations erroneously supposed to be mere imaginations. Importance of a faithful study of mental influences to the physician.
CHAPTER XV.
INSANITY,
Two classes of causes—those which act upon the mind, and those which act upon the body. Insanity always, strictly speaking, a disease of the organization. Too much disposition to look to some one thing as the cause. Tables of causes in Hospital reports. Form of the insanity not necessarily indicative of its cause, or of the character of the patient. Causes of insanity. Indulgence of passions. Wrong views of life. Exclusive and prolonged attention to one subject. Insanity rare among savages, and those under despotic governments. Great prevalence in this country. Religious excitement. Debilitated system predisposing to insanity. Intemperance. Children seldom insane, though very liable to temporary derangement in sickness. Foundation of insanity, however, often laid in childhood. Forms and signs of insanity. Cases in which the disease comes on slowly. Monomania. Moral insanity. Treatment of the insane. Change produced by Pinel. Advantages of Retreats or Hospitals. 1. Removal of patient from the associations under which his insanity originated. 2. Judicious medical treatment. 3. Better mental and moral management than can have among his friends. Mistakes of friends of the insane in their management. Reasons why insane apt to dislike their nearest friends most. Helplessness of insane poor. Duty of the State in regard to them. Legal relations of insanity. Absurd and inconsistent opinions and practices of our courts of justice. Professional evidence in France, and in this country, when prisoner suspected of insanity. Insane often been executed. Plea of insanity. Importance of preventing the acts for which the insane are brought before our courts as criminals. Laws deficient at this point. Necessity of a commission of lunacy.
CHAPTER XVI.
INFLUENCE OF HOPE IN THE TREATMENT OF DISEASE,
Physician’s employment a cheerful one. Contrary opinion quite prevalent, but erroneous. Cases in which he can neither cure nor palliate few. Prevailing cast of physician’s mind, therefore, hopeful. Hope should always be based on intelligent grounds. Hope in the different stages of a case. Seldom should all hope be given up—even in apparently desperate cases recovery sometimes occurs. Interesting case. Hope a cordial—as necessary as the cordial draught, and as improper to withhold it. Giving false assurances wrong. Often done by quacks and quackish physicians. Views and feelings of patients in regard to prospect of death often misunderstood. Extinction of all hope of recovery not commonly desirable in cases certain to be fatal. This extinction of hope not essential to perfect resignation. Influence of collateral circumstances upon the manner in which death is met. Occasional pauses in the onward progress of fatal chronic disease. Duty of the physician in regard to the hope awakened at such times. Supposed salutary moral influence of the certain expectation of death. Tendency to hope in consumptive patients. Curability of consumption.
CHAPTER XVII.
TRUTH IN OUR INTERCOURSE WITH THE SICK,
Variety of opinion and practice on this subject. Percival’s views in his Medical Ethics. Advocates falsehood. Object of this chapter to present the practical considerations bearing on this subject, illustrating them with cases. 1. Knowledge concealed from the patient by falsehood it is wrong to assume would certainly do him harm if communicated to him. 2. Deception as commonly practised generally fails to be carried out. Case of the deceived child. 3. The discovery of the deception, when it takes place, has a worse effect on the patient than a full statement of the truth could produce. 4. Destruction of confidence occasioned by discovered deception injurious to the persons deceived. Children. The insane. Detected deception not only increases insanity, but modifies it. 5. General effect of deception, extending beyond the individual on whom it is practised. General distrust of the veracity of physicians. 6. If adopted as a common rule that deception is sometimes proper, the object of the deception would be defeated. 7. If the door for deception be once opened there is no limit. Though proper sometimes to withhold the truth, wrong to put falsehood in its place. Enquiries of the sick not always to be directly and fully answered. Too definite opinions often given by physicians.
CHAPTER XVIII.
MORAL INFLUENCE OF PHYSICIANS,
Intimate relation of physician to his patients. Mutual confidence. Abuse of confidence. Guilt of it, especially in case of females. Sympathy of the physician—active—grows constantly stronger and more tender. Self-control mistaken for want of feeling. Manifestations of feeling—surgical operation. Certain nervous effects erroneously supposed to be evidences of feeling. Sympathy of the physician a means of influence. Physician at home everywhere. Opportunity of studying every variety of character. Physicians often fail to exert the influence which these advantages enable them to do. Influence on moral questions. Temperance. Acting as a peace-maker. Influence of daily conduct—little hourly acts. Physician in sick room. Communion with the spirit in its most momentous hours. Physician’s great object to cure the patient—nothing should interfere with it. Cordial influence of hope. Little confidence to be placed in death-bed repentance and reformation. Opportunities of doing good in lingering chronic cases. Mode of doing it. Injudicious intercourse with the sick. In some cases duty clear—in others, doubtful. Conference between physician, clergyman, and friends. Opportunity of doing good in convalescence. Moral influence of the physician in his strictly-professional character.
CHAPTER XIX.
TRIALS AND PLEASURES OF A MEDICAL LIFE,
Great mental and bodily toil. Irregularity of life. No command over time. Exposure to causes of disease. Physicians a short-lived class. Compensation generally small. Medicine not a money-making business. Less obligation felt by many to pay physician than to pay others. Physician often obliged to see the quack and hobby-rider getting rich by their impostures. Facility with which the people are imposed upon, a great trial to the honorable practitioner. Especially so when imposition is practised by his brethren. Valuable lives sacrificed to ignorance and unskilfulness. Witnessing sad scenes. Mutual sympathy and confidence add in such cases to physician’s sorrow. Irreligion and vice at hour of death. Frequency of sad scenes in times of pestilence. Ingratitude of those on whom the physician has conferred favors. Services of faithful physician not to be measured by pecuniary considerations. Dismissing physician for frivolous or improper reasons. Not so much gratitude in the world as commonly supposed. Virtuous and vicious poor. Clergymen generally attended upon gratuitously. What, therefore, is due from them to our profession. Conduct of some of them. Want of respect to the medical profession, on the part of the community generally. Public ingratitude. Pleasures of a medical life. Medicine as a science, full of interest. Its intimate union with other sciences. Enthusiasm in its pursuit. All discoveries, however small, add to the capabilities of the medical art in relieving misery and prolonging life. Pleasure in unraveling the perplexities of medical practice—in guiding and assisting Nature’s processes when salutary, and in arresting them when not so. Mental management of the sick. Results of practice of the judicious physician gratifying. The physician a hopeful, cheerful man. Gratification of his humanity and benevolence. His attachments. His social enjoyments. His opportunity for exerting a good moral influence.
CHAPTER I.
UNCERTAINTY OF MEDICINE.
The uncertainty of medicine is a common topic in all circles; and yet it is one which is very generally misunderstood, even by the intelligent and reflecting in the community. They mistake as to the nature of this uncertainty, its causes, its practical influence in the treatment of disease, the means which should be resorted to in order to diminish it, and the best methods of guarding against the errors into which it is liable to lead us. These errors are, I may remark, so numerous and so common, and interfere so constantly with the usefulness of the physician among high and low, educated and uneducated, almost equally, that the subject is one of vast practical importance. It is important not only to physicians, but to the people, and to the people especially, for they are the sufferers from the multiform and often fatal injuries, which these errors engender.
It will be profitable then to examine the different points to which I have alluded, so that it may be seen how far the science of medicine merits confidence, and by what tests an intelligent and thinking man may distinguish between that which rests upon good and substantial evidence, and that which is uncertain and delusive. This is a distinction which often fails to be made, (as the physician has occasion every day to lament,) by the shrewd and learned, as well as the ignorant and unwary; and the deductions of a rational and careful experience are continually confounded with the false assumptions, and plausible fallacies of the mere pretender, and the fanciful vagaries of the enthusiast. So far as my remarks will enable the reader to make the distinction to which I have referred, just so far will my object be accomplished.
When the chemist mixes substances together, the composition of which he knows, he arrives at results which may be strictly denominated certain and invariable. If he be not able to do this at once, he can do so ultimately, by a series of experiments, varied to test each doubtful point. The results which he thus obtains are so exact, that they can be expressed by numbers and definite proportions. The physician can imitate the chemist, it is true, in the application of tests in the investigation of disease; but it is necessarily a very humble and distant imitation, and no approach to the certainty and definiteness of chemical analysis and synthesis can be expected in medical practice. When the chemist mixes substances together, he knows what they are; and when he sees their effect upon each other, he has a right to expect the same effect to follow, with absolute certainty, whenever he shall make the same mixture again. But the physician cannot infer from the effect of a remedy in one case, that the same result will certainly occur in another case which appears to be precisely similar. For he cannot know enough of the circumstances of the two cases, to determine beyond a doubt that they are exactly alike. There are often causes, utterly undiscoverable by human wisdom, which essentially modify the effects of remedies.
If you suppose that the chemist knows the nature of only a part of the substances which he puts into his retort,—that the retort itself is made of materials which will act upon these substances, and be acted upon by them, and that in the midst of his experiment some other substance is introduced accidentally or by stealth, producing an entire change in the process; you will then make the chemist to resemble the physician in the uncertainty of his results. He would then be obliged, as the physician is, to go through with a great many observations to establish any one fact; and instead of making, as he now does, a well-defined line of separation between what is known and what is not known, he would, like the physician, have a wide middle ground of probability and supposition.
The causes which make disease complicated, and prevent uniformity in the effects of remedies, are principally these, viz.:
1. The sympathy which exists between the different organs of the body.
2. The influence of unseen causes or agents.
3. Natural changes, arising from the tendency which exists in the system to throw off disease, appropriately called the vis medicatrix naturæ, or restoring power of nature; and in connection with this the tendency to a definite limit manifest in many diseases; for example, small pox, whooping cough, measles, scarlet fever, &c.
4. Mental influences.
5. Idiosyncrasies, or individual peculiarities.
We will examine in a familiar way each class of these causes separately.
1. The sympathy which exists between the different organs of the body.
The fact that when one organ is disordered in any way other organs sympathize, or suffer with it, is familiar to every one. This sympathy destroys the simplicity of disease, in two ways. In the first place, it produces many symptoms at a distance from the organ affected. Pain, for example, is often far away from the disease which causes it. The pain in the right shoulder from disease of the liver, in the knee from disease of the hip joint, and in the head from disordered stomach, are familiar instances. Convulsions, in the great majority of cases, especially in children, are a mere symptom developed by the sympathy of the brain and nervous system with disease in some other organ—for example, a disordered stomach, the irritation of teething, &c. Now if sympathy renders disease complex, by developing such marked symptoms as those we have mentioned, at a distance from the affected organ, much more will it do this by the numerous less observable, and less definite symptoms, attendant upon our various bodily maladies.
In the second place, sympathy destroys the simplicity of disease, not only by exciting symptoms in organs at a distance from the part affected, but also by creating actual disease in those organs. A single example will suffice. The child, whose brain sympathizes with the disease in its stomach, may have inflammation after a time fastened upon its brain in consequence of this sympathy, the symptoms at first being obscure, but at length clear and unequivocal.
The influence of sympathy in modifying disease occasions constantly much perplexity in the mind of the physician. He often finds it difficult, and sometimes impossible, to decide whether an organ, which he sees to be affected, is really diseased, or is merely sympathizing with some other organ.
The simplicity of disease is thus destroyed by sympathy, even when all the organs, except the one which is attacked, are in a healthy state at the time of the attack. And when they are already in an unhealthy, unnatural condition from previous disease, the complication is rendered still greater. Chronic[2] cases especially are often so complex from this cause, that it requires the most discriminating acumen to unravel their history, and make out the starting point of the disease. Often it is impossible to discover any such starting point; and sometimes there is none, but there are several different diseases in different organs, all affecting each other through sympathy, and presenting together a confused and changing medley of symptoms. In such cases, the manifestations of diseased action are at one time most prominent in one organ, and at another time in another. These variations in the phase of the disease are often so unaccountable, as to seem capricious, and they always embarrass the physician, as he attempts to determine the effect of his remedies, and to proportion them to the importance of the symptoms, as they show themselves in the various organs. It would sometimes almost seem, that a tricksy little spirit were playing its pranks among the organs, now here and now there, eluding his search, and escaping his grasp.
In some cases, disease will leave the organ in which it seems to be obstinately fixed, and appear in full force in some other organ, which has been up to that time only sympathetically affected. This is more apt to occur in children, because the sympathies are more lively in them than they are in adults. Such changes, taking place often without any obvious cause, and so suddenly, and sometimes, we may add, so secretly, you can readily see, must tend to make our knowledge of disease, and of the effect of remedies, confused and uncertain.
2. The influence of unseen or secret causes, is another source of uncertainty in medicine.
The fact, that some causes, whose nature and extent cannot be appreciated, are at work modifying disease, and the effects of remedies, constantly forces itself upon the attention of the practitioner. The causes of disease, and of the changes that occur during its progress, are much more concealed from our view than is generally supposed. Patients are fond of fixing upon something to which they can attribute their sickness; but in the great majority of cases, the conclusion which they adopt with so much confidence is a mere supposition, and does not rest upon any substantial proofs. Even in the case of a common cold, you will find that the reasons given for believing that this or that cause produced it, often will not bear a strict examination, according to the acknowledged rules of evidence. Ordinarily some exposure is looked upon as being without a doubt the cause, when it may have been only one of the causes, or may even have had no agency at all in producing the result.
Some of the causes of disease, though, from their definite and invariable results, we may be perfectly aware of their presence, are yet of an occult nature, escaping all the tests devised to detect them. For instance, the miasm, as it is termed, which is the cause of intermittent fever, has never yet been detected in the atmosphere, by the application of any chemical test. And yet, no result in the wide range of disease is more definite and palpable than that which this miasm produces. And so secretly does it make its impression, that the disease sometimes lies dormant for a long period, even for weeks and months—the system all the while showing no signs of its presence. I once had a case of intermittent fever, which was not developed till a year had elapsed from the time of the patient’s exposure to the cause.
The nature and mode of operation of the causes of many diseases are involved in mystery, and are subjects of discussion and dispute among medical men. The formidable, and often fatal malady, that results from a wound received in dissection, is attributed by some to a poison evolved in the decomposition of the body; while others suppose that it arises from the irritation of the wound simply, circumstances concurring to increase the irritation in one case, while it is left to subside in others. It is agreed, on all hands, that the contingencies on which the disease depends are not ascertained; and they are so often absent, that the cases in which the malady does actually occur bear a very small proportion to the whole number of instances in which such a wound is received.
The same may be substantially said of the causes of typhus fever, cholera, scarlatina, &c. Some think that these diseases are caused by subtle poisons, which enter the system in various supposed ways; while others believe that they arise from causes which make impressions merely upon the system, and thus awaken trains of morbid action. Whatever may be our opinion on these disputed points, the fact that there is so much secrecy in the operation of morbific influences, must, it is clear, make much of our knowledge of disease uncertain.
If, then, there be so much ground for difference of opinion in regard to the nature of the causes of disease, and their mode of operation, where the results are of so definite a character, as we see in the disorders to which I have alluded; much more is this the case with those diseases, which, with their Protean shapes, make up a large proportion of the maladies that call for the daily attention of the physician. These do not commonly spring from one cause, but from many causes concurring together, some of which may be ascertained, while others are only suspected, or are wholly concealed from the most scrutinizing investigation. Under these circumstances, the physician has a difficult task to discover the actual condition of the patient. It would be a comparatively easy one, if he knew what all the agents were that had combined to produce the disease, even though they were numerous and complicated in their operation. He could then thread out with some success, the trains of morbid action, and, perhaps, give to each cause its proper place in his estimate of their agency in causing the disease. But, in some cases, he knows but little of the nature and mode of action, even of those agents, whose influence he can perceive: and then, there are some quite as important, which act in entire secrecy, developing results that cannot be foreseen, and that cannot be calculated upon after they have made their appearance. Such developments are often observed in the progress of disease, and necessarily embarrass us in its treatment. They sometimes completely alter, either gradually or suddenly, the whole character of the case; and yet they may be the consequences of causes, which have been secretly, but surely, doing their work from the first onset of the disease. In some cases, which were in the commencement comparatively mild, a group of severe symptoms all at once start up, exciting astonishment and alarm in the mind of the practitioner. Sometimes there are precursors of the full development, half showing themselves, and the watchful physician may discover in them the coming storm, long before the indications are manifest to the common observer. Even after convalescence has, to all appearance, fairly begun, and the symptoms seen during the progress of the disease are gone, some new symptoms may appear—the upshot of a train of morbid influences, which had been all the while imperceptibly advancing to this result; just as I have seen a fire, supposed to be extinguished, burst forth like a new fire in another part of the building, to which it had secretly made its way.
It is sometimes impossible to detect the immediate cause of an attack of sickness, even when the transition from health to disease is apparently instantaneous. Take, for example, this case. A gentleman, while quietly sitting in his counting-room, was attacked, as suddenly as if it were from a blow, with a great sense of oppression in the region of the heart, almost arresting the action of this organ, and at once prostrating his strength. No reason could be discovered why this attack should occur at that time rather than at some other. And yet there was some hidden cause, or combination of causes, which, at that moment, did its work; and we know not how long a time a preparation had been going on for this consummation, and so silently, too, as to occasion no disturbance.
The physician often finds, on making his first call upon a patient, that although he may think that his attack is only a thing of to-day, there is evidence that disease must have been preying upon his system for some length of time, gradually extending its ravages, till, at length, it has made a palpable outbreak. The patient may attribute his sickness to some one cause; but there have been many causes uniting together, one after another, and swelling the still current of disease, which has now broken forth as a flood.
And, as a general rule, the longer this preparation has been going on, the more obstinate does the physician expect the case will be, and the more difficulty does he find in getting a definite knowledge of the nature and extent of the malady. And if he could always trace every train of disease up to all its sources, both original and tributary, he would often be obliged to go back weeks, months, and sometimes years. In some cases, such an exploration would lead him through almost endless labyrinths. As it is, he often finds, in attempting such a search, that those facts which are the least material in the eyes of the patient, and which may be overlooked by him in giving the history of his case, reveal, far back in the distance, causes which have had more influence than any other in producing this result. A sort of cross-questioning, and that sometimes of a rigid character, is often needed, to develop material facts. The patient’s own story, without such questioning, would generally give to the physician very erroneous ideas of his case.
The remarks that I have made apply with greater force to chronic than they do to acute diseases. For in them more especially, as you have already seen, does the sympathy which exists between the different organs extend and complicate the morbid condition, and the operation of unseen causes contributes, sometimes very largely, to this result.
Many chronic cases become exceedingly complex, and therefore obstinate, from the course which the patient takes with himself, before he comes under regular and systematic treatment. Perhaps, first, he goes through with domestic medication, and then takes patent medicines, recommended to him by kind neighbors, or blazoned forth in the newspapers. Then he tries some vaunted system—Thompsonism, or hydropathy, or homœopathy, or chrono-thermalism, or perhaps all of them in succession. After going through all this, unless some one of these measures chance to benefit his case, (as anything may chance to do it), he at last comes to a physician, and puts himself under his care. The case which was, perhaps, sufficiently complicated in the beginning to require strict investigation, is now rendered, by all this variety of practice, very intricate. The difficulty in understanding it lies in the varied effects which the different agents brought to bear on it have produced—effects, which, in the retrospect, it is almost impossible to estimate with any correctness, because the physician has only the history given him by the patient, and the appearance of his present symptoms, to guide him in making up his opinions. If he had himself seen the case in its untouched condition, and then had witnessed the operation of the different remedies, he would have been better able to arrive at satisfactory conclusions. A chronic case, in its best estate, needs to be watched for some little time, in order to acquire a just and thorough knowledge of its character. And when it has gone through a series of processes at haphazard, with no intelligent eye to observe it, it is no wonder that its condition should become a complicated and puzzling one. The physician, with such a case before him, is situated very much as the chemist would be, into whose hands should be put a mixture which had been experimented upon over and over again by different chemists, and those, too, who were ignorant and bungling. And as you would not demand of him, that he should arrive at once at definite results in examining the composition of such a mixture, but would give him time to apply various tests to it, so it should not be expected of the physician that he should fully understand at once a case which has been dabbled with by ignorant experimenters, one after another; but time must be given him to watch his tests, that he may see them bring out to view its real character and condition.
It must be obvious to the reader, that those who go through this round of experimenting, before they put themselves under the care of an intelligent physician, not only lose valuable time by so doing, but generally inflict upon themselves positive harm. The remedies which they have used, if they have had no good effect, have helped to fasten the disease upon the system, and have increased its severity. They have done this by irritating the system, and, of course, the diseased organs, and by extending the complaint far beyond its original limits. You have seen that, through the sympathy existing between different organs, disease becomes extended and complicated. Well-directed treatment has a tendency to prevent this extension of disease: mere blind experimenting, on the other hand, is apt to promote it; and if it does not have this effect, the patient is very fortunate.
3. I pass now to the consideration of the third class of causes which render medicine an uncertain science, viz., natural changes, arising from the tendency which exists in the system to throw off disease, appropriately called the vis medicatrix naturæ, or curative power of nature; and, in connection with this, the tendency to a definite limit, which is manifest in many diseases, as, for example, small pox, measles, hooping cough, scarlet fever, &c.
To recur to our chemical illustration. I have said that it would add vastly to the uncertainty of the results of the chemist’s experiments, if the retort, into which he puts his substances to be experimented upon, could itself act upon these substances, and thus modify their action upon each other. The body of the patient may be considered as the physician’s retort, and the diseases and the remedies introduced, as the materials contained in it. Under this head we are to examine certain principles which reside in this retort, and which have a constant and important influence upon diseases and their remedies, modifying, sometimes manifestly, and sometimes secretly, their action upon each other.
I will speak first of the tendency to throw off disease, the vis medicatrix naturæ. I need not spend time in proving to you the existence of such a tendency. It requires not the exercise of any scientific acumen to discover it. It is obvious to the most superficial observer. And yet the extent to which it operates is far from being properly appreciated, even by medical men; and much less is it by those who are out of the profession. The changes which it produces are constantly confounded with the effects of remedies; and this is one of the chief sources of the errors which encumber the annals of medical experience.
The reader will see, as we proceed, that boast as doctors often will of their cures, as if they were wholly theirs, this vis medicatrix naturæ is the chief doctor after all; and she, good, kind angel, hovering over the bed of sickness, without fee, and often without even any acknowledgment of her services, saves the life of many a poor patient, who is near being drugged to death by some ignorant quack, or some over-dosing doctor.
That the reader may be somewhat acquainted with the extent of the influence which this curative principle exerts, I will cite some examples of its operation.
If some offending substance be present in the stomach, vomiting is produced, the substance is evacuated, and this organ, having thus relieved itself by an effort of nature, as it is commonly expressed, now goes on with the performance of its usual functions. In this case, the ordinary action of the organ is entirely reversed, in obedience to the curative principle. If an attempt be made to allay the vomiting before the offending substance is thrown off, it is an injurious interference with a salutary effort. Sometimes the effort is ineffectual, and needs the assistance of art. It is often difficult to decide whether vomiting is prompted by this curative principle, or is caused by irritation, which should be quieted by medicine. Want of due discrimination, either from lack of knowledge, or from carelessness, very often leads to errors on this point.
The operation of this principle is beautifully exhibited in the succession of the processes of inflammation. You see a swelling. It, after a while, begins to soften. There is matter in it, but it is not yet very near the surface. But soon, at some point, it comes nearer and nearer to the surface, the wall of the abscess thus becoming constantly more thin, till, at length, it opens and discharges. The discharge continues till the swelling is nearly all gone, and the remainder is absorbed, and the part is restored to its natural state.
Now, this is quite a series of processes, all contributing to one result, and it is presided over, or directed, by the vis medicatrix naturæ. The object of this series is a definite one; and each process does its part in effecting it, and does it commonly at the right time, and in the right manner. Just look for a moment at the complicated character of this apparently simple operation. Here is quite a large deposition of substance which is to be removed; and this is the object to be effected. Observe how it is done. The softening of the swelling is not a mere change of solid substance into a fluid, as if by decay, but it is the result of an active process, which we call suppuration. When this process is properly performed, good pus is made, or as the old writers in medicine rather quaintly expressed it, laudable pus. This process of suppuration, when it is well done, does not go on here and there in the swelling, making it like a honeycomb with a multitude of little abscesses; but there is a consent, an agreement of action by the vessels of the part, as really as if they worked intelligently. It is this consent of action which not only makes the line of movement in the abscess, but points it towards the surface, instead of giving it some other direction, laterally, or inward, upon some of the internal organs. But it is farther to be observed, that in this agreement of action, the vessels of the part do not all do one thing. Three different offices are performed by them in the different quarters of the abcess. While some of these little workmen are forming the pus, there are others thinning the wall of the abcess in the direction of the surface, by absorbing or taking up the substance there; while there are others still, in the rear, and at the sides of the abcess, depositing substance, in order to make a barrier to prevent the pus from being diffused in the surrounding parts. Each class of these workmen perform their particular work with even more exactness and harmony than would be expected of any company of intelligent laborers under the direction of a leader. The absorbents absorb together, the wall builders build together, and the makers of pus make pus together, and deposit it in a common reservoir.
But observe farther, and you will soon see an entire change come over the whole scene of operations. When the absorbents have completed their passage for the matter through the skin, the pus is gradually discharged from its reservoir, and the “occupation” of the pus makers is soon “gone.” The wall builders also cease their work, and while the vacancy becomes filled up by contraction and deposition, the wall of defense, so carefully maintained, so long as it was needed, is now taken up by the absorbents—workmen which seem to know just when, as well as how, to do their duty, and is emptied into the common circulation, to be discharged from thence with the general refuse, by the various outlets of the system.
The object of all this is the restoration of the part to its healthy condition, and it is effected by a principle existing in the system—it matters little comparatively by what name you call it. The name is simply expressive of a great, general fact, as the term gravitation is, and is not intended, any more than that term is, as an explanation of the nature of the fact indicated.
This same principle is in operation in all diseases, resisting them, hemming them in, and as they retreat, following hard upon their footsteps, repairing their injuries as well as it can. It is true that its efforts are often ineffectual, that they are sometimes overpowered by disease, that they are frequently perverted by injudicious interference, and that they are sometimes stimulated to a higher degree than is necessary, producing over-action, and thus making this conservative principle an instrument of injury, perhaps destruction. It would be interesting and profitable to illustrate these several points in the operation of this principle, but it is not essential to our purpose.
We will pass now to the consideration of the principle of self-limitation,[3] which we find existing in many diseases. These diseases have a regular rise and decline, including a set of processes, and a succession of symptoms peculiar to themselves. When they have once fairly begun, they cannot be abridged; neither are they prolonged beyond their natural limits, though they may, and often do, leave results behind them, which are sometimes mistaken for a continuance of the disease itself. The period of continuance is more definite and fixed in some of these diseases than in others, and there is a similar difference also in regard to uniformity of shape. Thus small pox runs through its course with more regularity of period, and with a more uniform series of phenomena than scarlet fever, which, though having a certain general character and average period, is extremely diversified in its degree of severity, and in its accompanying circumstances. The more simple and regular and definite any disease is, the more accurate can our observations be in regard to it, and the less apt are we to confound the effects of remedies with the natural changes that take place in its progress.
This principle of self-limitation is found in the movements of other diseases of a less definite character than those which I have mentioned, though it does not manifest itself so fully, and with so much uniformity. You have already seen, that in a common inflammatory swelling there is a regular set of processes going on to its termination, in the restoration of the part to its healthy condition. The tendency of the inflammation ordinarily is to finish itself, just as is the case with any of the definitely shaped diseases, but its rate of progress cannot be so well calculated upon. The same can be said of inflammation of any of the organs of the body, in regard to this tendency to come to a conclusion of itself; the ways in which it does this varying much, according to the texture of the part affected, and other circumstances.
The reader is now prepared to see how it is, that mistakes may be made, by confounding the effects of remedies with the changes that arise from the two tendencies, of which I have been speaking. These mistakes have often been committed, even in those diseases which are commonly simple and uniform, and definite in their shape and course. Take, for example, small pox. It was once the custom of physicians to give much medicine in this disease, with the idea that it was controlled and lessened by such a course, and the system was thus enabled to throw it off more easily and effectually. But experience has corrected this error, and the physician now stands by, and sees results occur in the progress of this malady without the agency of medicine, which he used once to consider as produced, in part at least, by the drugs that he administered. Let me not be understood to say that no medicine at all should be given in this disease. The office of the physician is to watch it, and if nature, in going through the processes necessary to a favorable termination, needs to be assisted by art, it should be done. But we should be careful not to ascribe to art what is really effected by nature, for we should be led by this error to a too officious interference with her efforts. We may often do much good by medicine—we may moderate the fever, support the strength when languishing, bring out the eruption when it recedes, &c. But to attribute the successful termination of small pox in all cases to the remedies which have been used, would be as great an error as it would be to maintain that the poultices, and other applications made to an inflammatory swelling, are of course the cause of its suppuration and discharge—or, in other words, that they cured the inflammation. All that can be truly said of them is, that they assisted nature in the cure. And as these applications may sometimes be of too stimulating a character to suit the case, and therefore may increase and extend the inflammation; so the remedies used in a case of small pox, if they be not actually needed, may aggravate the disease. And if the patient recover under such injudicious treatment, it may be supposed that the medicines cured him, though he actually recovered in spite of them, because that same blessed vis medicatrix naturæ came to the rescue.
If there be so much liability to error in a disease so simple and uniform as small pox is, it is still greater in those complaints which are more complicated, from collateral and accidental influences and affections. Perhaps I cannot adduce a better example for our purpose than is to be found in scarlet fever. There is no disease, the history of whose treatment shows so strikingly the uncertainty of medical knowledge and experience as this does. The most opposite and various remedies and modes of treatment have been lauded as successful, in standard medical works, and in medical journals, and multitudes of certain cures have been proclaimed in the newspapers. What is praised by one is condemned by another; and it is the individual experience of every rational and candid practitioner, that a mode of treatment which at one time is attended with marked success at another is wholly unsuccessful. It cannot be otherwise in a disease which varies so much as this does in its degree of severity, in its real character, and in its attendant circumstances. A respected medical friend, in reviewing his cases of scarlet fever, found that he had treated one hundred cases since he had lost a patient with this complaint. But on the very day on which he made this review, he was called to a case of scarlet fever which ended fatally, and out of thirteen cases in the same neighborhood he lost seven. With such variations in the severity of this disease, it is very difficult to avoid erroneous inferences as to the comparative success of modes of treatment. This difficulty is increased by the fact, which is remarkable in this disease, that the degree of severity, or amount of danger, is by no means always capable of being measured by the symptoms which present themselves. In the experience of every physician, who has seen much of this complaint, many cases have ended fatally, which, up to within a short period before death, appeared to be doing better than some others in which recovery took place. There was much wisdom in the reply that one physician made to another, who asked him what his mode of treatment was in scarlet fever. “I have no treatment,” said he. “I manage each case as an individual case, just as it strikes me at the time.” And to this conclusion will experience lead every judicious practitioner.
Let me not be understood to mean that experience, so valuable in the treatment of all other diseases, is nothing worth in this complaint—that it establishes no facts, and no general principles. All that I mean is, that this disease is so variable in its character and tendencies, that extreme caution is necessary in applying these principles, and that the treatment must be at the very antipodes of stereotype—as variable as the disease itself.
I trust that it is sufficiently obvious to the reader that great uncertainty must necessarily rest upon our knowledge of a disease so varied as this is, and that all our experience of the effects of remedies upon it must be thoroughly sifted, in order to attain to any measure of accuracy. It is a disregard of this important truth, that has made the testimony of medical men so conflicting in regard to the treatment of this disease.
I need not spend time to show how the same uncertainty must embarrass us, to a greater or less degree, in our investigation of all other diseases. The errors resulting from this source may be avoided, in part, by observing accurately the changes which arise from the two tendencies that we have been considering, their modes, periods, signs, and accompanying circumstances. The efficacy of this precaution against error is, as I have already hinted, in proportion to the simplicity and uniformity of disease. In disorders which are complicated, and which vary much in their shape and other circumstances, it is exceedingly difficult to decide, how much agency, in bringing about the curative changes, is justly to be referred to the remedies, and how much to the natural energies of the system. Too much credit is very commonly given to medicine, and too little to nature; and sometimes, when some remedy is praised for its efficacy, and the patient and his friends, and perhaps even the physician, think that it has saved his life, it had no agency in promoting his recovery, and perhaps it retarded it.
I pass now to the consideration of the fourth class of the causes of the uncertainty of medicine—mental influences.
It never should be forgotten in our observation of disease, that we have not to deal with the body alone, but with the body inhabited by a mind, which is connected with every particle of that body by countless nervous filaments, and therefore acting through them upon it, and affecting to a greater or less degree all its diseased conditions.
The influence of causes acting through the mind is often concealed from our view, and even when it can be plainly seen it is difficult to estimate its amount with correctness. Effects are often produced through the mind, which are attributed by the patient, and sometimes by the physician, too, to some remedy that has been administered. Take a very common case. A dyspeptic, who has contracted his disorder from mental effort, or from the anxieties of business, applies to his physician. He prescribes some medicine, and at the same time recommends him to take a journey, or go to some watering place. He returns cured, and he perhaps gives the credit for the most part to the medicine, or to the medicinal waters which he has drank with scrupulous regularity, either of which may have had little if anything to do with the cure, and relaxation and diversion of mind may have been the chief or sole causes of his recovery. This is a palpable instance of erroneous inference; but we shall have but a narrow idea of the influence of mind upon disease, if we confine our view to cases of so decided a character. Its influence is constant in all diseases; sometimes plain to be seen, as in the case just mentioned; often entirely concealed from the most careful scrutiny; and sometimes revealing itself slightly, so that the watchful eye of the physician catches mere glimpses of it, like passing shadows gone in a moment. Besides the secret griefs and troubles that often hinder recovery, there are varying states of mind, some of which the patient may be hardly conscious of himself, that modify in a thousand ways the movements of disease, and the action of remedies. For example, the cordial which is administered is often in part or wholly neutralized by mental depression, while it is essentially aided in its effects by the genial and animating influence of hope.
The points to which I have alluded the reader will find fully illustrated in the chapter on the mutual influence of mind and body in disease. I will therefore dismiss them for the present, and will merely recur again for a moment to our chemical illustration. If the retort of the chemist, besides being composed of substances which will act upon its contents, should have residing in it some secret and subtile principle, whose existence is known only by its effects, and which acts both upon the retort itself and on whatever it contains, the results of his experiments would be rendered very uncertain. To follow out the analogy—the human body being the physician’s retort, the mind is just such a secret and subtile principle, acting in an unseen way both on the retort and its contents, modifying therefore the effects of remedial agents, so as to embarrass the physician in his investigations, and render his conclusions uncertain.
The fifth class of causes of the uncertainty of medical science remains to be noticed, viz.: individual peculiarities or idiosyncrasies, as they are termed.
Every individual may, strictly speaking, be said to be peculiar to some extent, and there is much force in the popular idea of the benefit resulting from a physician’s being acquainted with his patient’s constitution. But besides these common differences, some have very great peculiarities. A few examples will be sufficient. There are some persons in whom the odor of roses will produce asthma. Ipecac has the same effect in some individuals. Some persons are uniformly made sick by eating strawberries even in small amount. Cases are constantly met with by physicians in which some medicines have a peculiar effect. The various effects produced by opium in different individuals furnish many examples. I call to mind a patient, who though a laboring man of considerable power of endurance, is extremely prostrated by vomiting, by whatever agent it is produced. I once gave him an emetic without knowing this peculiarity. He was so much prostrated, that I supposed that the apothecary had made a mistake, and that he had taken an overdose. But a short time after, I witnessed in him the same effect induced by undigested food, and this revealed the idiosyncrasy in his case.
When idiosyncrasies are known, they can be calculated upon. But they are not always known. We cannot be aware of them when they respect the action of remedies which the patient had never taken. And in relation to remedies which produce no marked and obvious effect, peculiar susceptibilities may exist without being readily ascertained. If there be an idiosyncrasy in regard to such a medicine as an emetic, or an opiate, it is easily discovered. But if it exist in regard to a remedy that acts silently and slowly, it may not show itself clearly. The only evidence that we have of its existence may be the fact, that the medicine after a while is observed to fail in producing the effects which we ordinarily expect from it in such cases. And it may be very doubtful whether this failure is to be attributed to this cause, or to some other.
Let us recur once more to our illustration from chemistry. If the retorts used by the chemist, (which, I have supposed to carry out the analogy, to be composed of materials which would act upon their contents,) were not all made exactly alike, but varied a little always in their composition, and sometimes considerably, and that too without the variation always being appreciable, this fact would obviously still further complicate his experiments, and render them uncertain in their results. So also the peculiarities in the different human systems, which are the physician’s retorts into which he introduces his agents, must have the same effect upon his investigations.
I have now finished the consideration of the various causes of uncertainty in medical science. If I have succeeded at all in making them to be properly appreciated, the reader will agree with me when I say, that there is no science that requires higher talents for its successful investigation, and none that is so liable to wrong influences and conclusions, if the student of it be a careless and credulous observer. Notwithstanding this liability, imperatively demanding caution on the part of the physician, there has been much of careless observation in this science; and the recorded experience of the medical profession is therefore encumbered with a mass of errors. In order to get rid of these errors, and to establish the proper distinctions between the certain and the uncertain, between the true and the probable, while the merely plausible shall be entirely rejected, a judicious sifting and testing of evidence must be resorted to, credulity and skepticism both being equally avoided.