in degree, being sometimes very mild, sometimes violent, or furious, and of all intervening grades. The milder grades are usually evinced by some mental aberration, with little disposition to action; the higher grades by superadded violence of gesture, voice, and language. In the passive delirium, the brain acts wrongly, because it cannot elevate itself to the point for the due perception of impressions, or the formation of judgments. Of this kind is the low muttering delirium of typhus. It often happens, in passive delirium, that an increase of the proper stimulus restores temporary correctness of thought. Thus, though the patient may be muttering sentences without apparent meaning; yet, if roused, and spoken to in a loud and distinct voice, he will often answer coherently and correctly. Sometimes in delirium, there is a complete derangement of mind. The patient recognizes neither the persons nor the things around him. He is very apt to imagine himself in a strange place, and to insist upon returning home. This is often a bad sign. In other instances, the sensations and perceptions are correct, but the judgment is perverted. In others, again, only the perceptions are wrong, while the mind acts rightly upon the perception which it forms. Thus, the patient sees objects and hears sounds which do not exist, and acts as if those sights and sounds were real. When the fallacy of the perceptions or sensations is recognized by the patient himself, he cannot be said to be delirious. Facial Expression.-This is of the greatest importance, and should be carefully studied by every practitioner. It is occasionally almost our sole dependence in diagnosis. Through it, we sometimes recognize the existence of pain, mental anxiety or depression, insanity, and even, in a general way, pectoral or abdominal disease, when other signs are either wanting, obscure, or not available. In the cases of children, of the insane, and of persons who may be disposed to deceive us, it is a peculiarly valuable resource. Many diseases are attended with a characteristic aspect of countenance, which will often ke recognized by the experienced, so far at least as to suggest the disease to his mind. By a glance, we can often ascertain whether our patient has changed for the better or worse in our absence. But it is only by experience, and close observation, that this power is attained. The modifications and combinations of feature which constitute expression are too numerous, intricate, delicate, and evanescent, to admit of analysis, at least of profitable descrip tion. There are, however, certain changes in the face of a more tangible character, connected rather with the organic functions than the action of mind, which can be more accurately appreciated. The colour, shape, temperature, and various movements independent of expression, often yield important indications. Thus, a bright-red colour signifies one thing, a dark-red, purple, or violet colour another. In the former case, the blood is duly arterialized, and probably sent up vigorously into the head; in the latter, it is unduly carbonaceous, and probably detained in the head by some obstruction to its return. Paleness also has its significations, as of auæmia, debility, nausea, &c.; and there are different kinds of paleness having different meanings, as that of scrofula or phthisis, and that of cancer. Yellowness of face is well known to point to disease of the liver. The colour of the lips is peculiarly expressive, in its different tints of crimson, purple, and paleness. The fea tures may be full, swollen, turgid; or they may be shrunk, contracted, fallen; in the former case indicating oedema, or congestion, active or passive; in the latter, exhaustion, prostration, general collapse, &c. The Hippocratic fuce, so named because described by Hippocrates, is often referred to by writers as marking the near approach of death. It is characterized by a general con traction of the features. The nose is pinched, the temples hollow, the eyes sunken, the ears cold and shrunk, the skin of the forehead tense, the lips parted and relaxed, and the colour of the face pale or livid. Coldness of the ears and tip of the nose occasionally indicates the approach or presence of a chill, when other symptoms are wanting or ambiguous; and, in infantile cases, coolness of the cheeks, nose, and ears, sometimes enables us to decide upon the existence of a degree of prostration requiring support, when we might be embarrassed without that sign. Certain positions or movements of the features are sometimes also highly expressive. Thus, alternate contraction and expansion of the alæ nasi frequently indicate dyspnoea; irregular motions of the eyes, with contracted or expanded pupil, disease of the brain; and a falling of the under jaw, the last agony. 8. SYMPTOMS BELONGING TO THE MOTOR FUNCTION.-These arise from a deficiency or complete want of muscular contraction, as in debility, palsy, or local disease of the muscles; from an excess of contraction, as in spasm, convulsions, and subsultus tendinum; or from irregular or perverted contraction, in which the muscles act under the will, but not to the end proposed, as in chorea. Under this head are included all the voluntary motions; the gestures, the manner of walking, running, &c.; the positions, as standing, sitting, and lying; and all the symptoms connected with the voice, and speech, as suppression of voice, hoarseness, shrillness, dumbness, stammering, &c. But these symptoms, and many others belonging to the different functions not here noticed, will be most advantageously studied in connexion with the several diseases in which they are found. Our limits do not permit of ampler details in this part of the work. SECTION II. COURSE, DURATION, AND TERMINATION OF DISEASE. By the course of disease is meant the succession of its symptoms, in relation both to order and rapidity. When, from the commencement to the ter mination, the symptoms show no disposition to abate, or when they regularly increase in violence up to the point at which recovery begins, or the patient sinks, the disease is said to be continued. Neither of these events, however, often happens, unless in diseases of very brief duration. More commonly, the symptoms, after a shorter or longer continuance, abate considerably, with out, however, entirely disappearing, and, having remained for a time in this state of relaxation, resume their original violence, again to abate as before; and this alternation of excitement and relaxation continues to the end. The disease, under these circumstances, is said to be remittent, the period of abatement is called the remission, and that of excitement the exacerbation. Frequently, all the symptoms yield entirely for a time, so as to leave regular intervals in which the patient is apparently free from disease. The complaint is then said to be intermittent, and the interval is called the intermission; while the stage of excitement is designated as the paroxysm. The period at which the remission occurs may depend on the nature of the morbid condition, and, in that case, is peculiar in each disease; as on the third or fourth day in smallpox, and on the second and third day in yellow fever. It may also depend on causes unconnected with any particular disease, and existing either in the constitution of the frame, or in the influences to which it is subjected from without; and, under the operation of these causes, the remission occurs, in most diseases, at similar intervals, usually once in twenty four hours. It is a law of our physical as well as moral nature, that excitement, even under the constant influence of stimulating agencies, cannot be long sustained at a particular point of elevation. We see this every day in health. The various agents, such as food, drink, heat, light, &c., which are necessary to sustain the system in its proper condition, may be present in an equal degree throughout a given period; yet the excitement produced by them flags after a time, and sleep, with a general reduction of the vital actions, occurs. So, under the influence of some morbid excitement, the action flags for a time, though the application of the excitement be continued. During this state of comparative rest or diminished excitement, the system acquires additional excitability, which renders it again susceptible to the influence of the stimulating agent; and the temporary reduction is, therefore, followed by a renewed elevation of the diseased process. It has been before observed that this change of remission and exacerbation usually takes place once in twenty-four hours. The cause of this is probably to be found in that habit of the system, acquired by the daily alternation of waking and sleeping. The excitability of the former condition being regularly diminished in the latter, a flux and reflux is established, which, in cases of disease, though it may occasionally vary in the precise point of accession or decline, is still, as a general rule, experienced within the habitual limits. Upon the same principle, to a certain extent, may be explained the disposition observable in intermittent diseases to a daily return of the paroxysm. The cause of the disease gives rise to the first paroxysm at that period of the twenty-four hours, at which, in the advance or recession of the excitability, the system is in the most favourable condition for its action. The same condition is experienced about the same time on the following day, and the same result necessarily takes place, if the cause continue to operate. That the paroxysm should often occur every other day, and sometimes every third day, as in the tertian and quartan agues, must be referred to some unknown modification in the character of the cause, or in the properties of the system, which prevents the equilibrium of health from being disturbed on the first favourable occasion, and enables the vital resistance to triumph over the morbid influence, till, weakened by continued assault, it is compelled at last to give way. Disease sometimes runs its course speedily, and sometimes is of long duration. In the former case, it is said to be acute, in the latter, chronic. These terms, however, are not definite. There are no characteristic signs which serve in every case to distinguish an acute from a chronic complaint; and the terms are not unfrequently employed to express different stages of the same affection; the disease being called acute in its earlier course, when the symptoms are most severe, and chronic, when its duration has become protracted, and its violence considerably abated. There is another distinction between diseases, which is of considerable practical importance. Some appear to have no definite course, duration, or end; being more or less variable in the succession of their symptoms, lasting a less or greater length of time, and terminating favourably or otherwise, according to circumstances in the constitution of the patient, and in his relation to surrounding objects. Others, on the contrary, whatever may be the constitution, habits, or exposure of the patient, are disposed to pursue a certain course, and in a given time to end in recovery, unless fatal disorganization arrests their progress, or derangements of structure of a less violent character, resulting from the disturbance into which the system has been thrown, impede their march towards health. A third set of diseases are those which exhibit no tendency to a favourable issue, and which, if left to themselves, and sometimes in defiance of all treatment, go on gradually increasing in intensity till they ultimately destroy the patient. Examples of the first class are presented in rheumatic inflammation and neuralgia, of the second in smallpox and other exanthemata, and of the third in cancer. It is obvious that our treatment must be very much influenced by these differences in the tendencies of disease; being directed to the subversion of the morbid action, in cases which admit of a direct cure, and to the prevention, as far as possible, of dangerous consequences in those which run a fixed course; while, in those of an incurable nature, we must be content with endeavours to alleviate the sufferings and protract the life of the patient. It is particularly important that the practitioner should bear in mind the disposition of many, perhaps we might say of most diseases, to terminate favourably after having run a certain course, provided fatal organic injury can, in the mean time, be prevented. With this conviction ever present to his mind, he will be less disposed to waste his own efforts, and the vigour of the patient, in vain attempts to effect an immediate cure; and, even in cases in which the disease may possibly be arrested in its progress, will often prefer such moderate measures as will insure ultimate recovery, in the natural course of things, to the chance of more speedy success from violent remedies, with the risk of serious mischief. Crisis. The name of crisis is usually applied to the turning point of disease; the point at which it begins to give way, if its end is to be favourable, or to become decidedly worse, if unfavourable. This period is often attended with certain phenomena which mark the favourable or unfavourable change, and are, therefore, denominated critical symptoms. The most common of these are augmented secretions, hemorrhages, cutaneous eruptions, glandular swellings, and abscesses. The secretions are usually from the skin, bowels, and kidneys, constituting critical sweats, critical diarrhoea, and critical din resis. At one time, great importance was attached to these discharges. It was supposed that they carried the peculiar peccant matter out of the system, thus proving positively curative; and any interference with them was strongly deprecated. Though this view of their influence is no longer entertained; yet they are still looked on by many as, in some instances, very useful, by removing irritation or congestion, or, when of an inflammatory character, by calling off diseased action from its seat, upon the principle of revulsion. In most cases of disease, however, there are no symptoms which can strictly be denominated critical; and, when they do occur, they may be considered, in general, as coming under one of the three following heads. They are either, first, regular results of the pre-existing morbid conditions, explicable upon ordinary pathological principles, as when the excited vessels of the skin in fever unload themselves by perspiration; or, secondly, transfers of disease from one organ to another, under various accidental influences, as when rheumatism ends in diarrhoea; or, thirdly, new diseases supervening upon those already existing, and superseding or increasing them, as the case may be, as when an attack of bleeding piles, occasioned by straining at stool, relieves an existing attack of splenitis or hepatitis. Hippocrates believed that disease, in general, was more disposed to change at certains periods than at others; and he designated the 7th, 14th, 20th, 27th, 34th, and 40th days, as constituting the periods alluded to, which he named critical days. It will be perceived that the intervals between the days mentioned are very nearly a week; and Hippocrates considered the crisis as falling on the last day of each septenary period. He carried the doctrine further, and supposed that there were certain intermediate days, in which, though the tendency to change was not so strong as in those men tioned, yet that it existed in a certain degree; while there were others in which the disposition was still less, and others again in which a crisis never occurred. These notions of the father of medicine certainly do not apply, with any great accuracy, to diseases as they now exist; yet there appears to be some vague relation between disease and weekly periods of time; for many complaints show a disposition to end in about seven days, more or less; and it is a subject of constant observation, that miasmatic fevers, when they return after being checked, are apt to do so in one, two, or three weeks, or some other septenary period, most frequently perhaps at the end of the second week. This tendency is, in the present state of our knowledge, quite inexplicable. Termination.-A particular disease may terminate in convalescence, in some other disease, in the chronic form of the same disease, or in death. Convalescence is sometimes sudden. There is an immediate transition from disease to health. This is most apt to happen in nervous affections. But much more frequently the change is gradual. Among the first symptoms of convalescence from acute disease are generally a commencement of the cleaning of the tongue, and a diminution in the frequency of the pulse. The skin, if before dry, is apt to become moist, the other secretions are gradually restored to their normal condition, and all the functions are in the end re-established. Emaciation, however, is usually more striking in convalescence than in the previous illness. This may possibly be in part merely apparent, and the result of the principle of association, which expects healthy looks in returning health; but it is probable that the nutritive process does not at first keep pace with the vigour of absorption, and that the body for a time really loses more than it gains. Convalescence often goes on happily; but often also it is disturbed by unpleasant symptoms, and interrupted by drawbacks, consequent upon the irregular action of the debilitated or perverted functions. Copious night sweats are frequent; the appetite is sometimes feeble, and requires stimulation; the bowels are apt to be constipated; the pulse often remains frequent; and the patient is troubled with various nervous symptoms, such as restlessness, wakefulness, and extraordinary dejection of spirits, or fanciful and hypochondriacal notions. These, however, gradually disappear, spontaneously, or under appropriate treatment; all the functions become active; and the oscillation not unfrequently extends even beyond the original standard of health. The appetite becomes voracious, nutrition abnormally active, and the body swells considerably beyond its previous dimensions. The various sensibilities have been as it were regenerated, everything is for a time enjoyed with the zest of youth, and life has acquired new charms. Sometimes the increased fleshiness continues a confirmed habit of the body; but more frequently it subsides to the original level, and the individual becomes his former self again, with the exception, it may be, of the loss of some previous morbid tendency, or the acquisition of a new one. The hair is very apt to fall after severe illness, and sometimes does not return, especially in advanced life; but generally its place is supplied by a new and equally luxuriant crop. It is thought that shaving the head has the effect of favouring the latter result. Sometimes convalescence is interrupted by a return of the disease, which is then said to have relapsed, and the new attack is called a relapse. Some diseases seldom if ever relapse. This is especially the case with those which depend on a specific poison, run a certain course, and are usually taken but once, as smallpox, measles, &c. These not unfrequently leave unpleasant sequelæ behind them; but it is very rarely that they run over their course again. Others are very prone to relapse, as the miasmatic fevers, rheumatism, and the phleg |