is particular, in order to preserve or re-establish the regularity of its functions.

180. This doctrine is confirmed by the observation of nature. It was upon it too that Van Helmont grounded his practical views. Unfortunately he fancied that genius could supply the place of observation; and, rejecting with disdain the facts which had been collected by his predecessors, he boldly adopted plans of treatment that were entirely novel. After the example of Paracelsus, he aimed at the prolongation of human life; he flattered himself that he had discovered the secret, and proclaimed it with the greatest assurance; and, like his predecessor, he shortened his days by those brilliant discoveries which ought to render their authors immortal. 181. We have now arrived at the commencement of the seventeenth century, at which time Dr. William Harvey of London first announced the very important discovery of the blood's circulation; a discovery which furnished a new ground for the whole body of physiological and pathological speculation. Most of Harvey's contemporaries refused to subscribe to the fact, while some endeavoured to deprive the author of the merit of the discovery. We have already had occasion to see how confused and imperfect even Galen's views were with respect to the mode in which the blood makes its passage from the centre to the circumference; he had indeed no idea of a regular circuit. Servetus, the noted object of Calvin's persecution, was a Spanish physician, and in a medico-theological work he mentioned that the blood finds its way from the pulmonary artery into the veins; but, even allowing that such intimation laid claim to a discovery, it is at best but a discovery of the pulmonary circulation, and cannot possibly be considered as any thing like an anticipation of the great Harveyan doctrine. Servetus indeed with Galen limits the blood to the liver and veins generally, and, confusedly and inconsistently with his other assumptions, imagines the heart and arteries to be the instruments of aerial or spiritual transmission. Columbus also, to whom the discovery of the circulation has been attributed by some, although he seemed to have an idea of the pulmonary circulation, and although he described the structure and office of the valves of the heart, fell in with the Galenic notion of venous origin; and Casalpinus, who very shortly followed him, still manifests confusion when he mentions the mode in which the system is supplied with alimentary blood; in a word, the actual transmission from, and return to, the heart of the mass of circulating blood, was first unequivocally detailed and explained by Dr. Harvey; and it might have been anticipated that from this time forward medical doctrine and medical practice, commencing as it were from a new starting point, would have regularly, if not rapidly, proceeded on to a state of comparative perfection. But no; this new instrument of truth was destined to become, in the hands of men prone to error, a new excitation of fanciful and futile hypotheses and systems. As the Paracelsian chemists, and the disciples of Helmont, had derided the Galenic faith, so the chemical æra now in its turn gave way before

the fury and fanaticism of a mathematical mania, which by axioms, postulata, and corollaries, attempted to explain the functions of life and the features of disease. Nothing now was thought of but hydraulic motion, and mathematical calculation of forces; the circulation of the blood, and the laws regulating it, constituted the whole compass of physiological and pathological principia; and medicine was from first to last correcting circulatory impulse, or changing the circumstances and condition of the blood. How futile and far from truth some of the positions and inferences of the mathematical physicians were, may be inferred from the vast difference of premises and deduction which different theorists broached in reference to the same particulars: while, for example, one estimated the force of the heart at a few ounces, another calculated it to be many pounds. And, with regard to the practical inferences which resulted from these mathematical dogmata, an author, from whom we have already largely borrowed, expresses himself in the following terms:-The new light which was thrown upon the animal economy, by this important discovery (the circulation), served only we may affirm to redouble the rage of systems. Nothing else was thought of but to cause the blood to circulate more freely, to destroy its viscosity, to draw off from the body that which was supposed to be corrupted, to purify it, correct it, and renew it, and to preserve the blood vessels in a relaxed and pervious state. Hence those torrents of aqueous and diluent drinks, with which Bontikoe and his adherents inundated their patients. Hence that sanguinary fury which the partisans of Botalli thought themselves entitled to exercise in their treatment of all sorts of diseases; a fury which, though so often damped in some measure by systematic murders, has ceased only for intervals, and still, from time to time, re-appears in the schools.

182. Thus one of the most beautiful discoveries of modern medicine, far from elucidating the practice of the art, as there was every reason to expect, only had the effect of misleading weak imaginations, dazzled by its splendor; and it may still be doubted whether its application to the knowledge and cure of internal diseases has been of any real use. In surgical cases, even where its assistance is generally regarded as indispensable, might not observation almost always supply its place? and must we not limit its importance to the elucidation of a point in anatomy and physiology, very curious no doubt in itself, but which, if it did not indirectly affect many other interesting questions relative to the animal economy, would perhaps have contributed very little to our knowledge of its true laws?

183. However, under this point of view alone, the discovery of the circulation has been productive of advantages by which the practice of medicine has eventually profited; and the glory of its authors can be contested only by the most ridiculous envy, or the most inconsiderate attachment to paradox.

184. The chemical theories of acids and alkalies, which were applied to the fluids of the living body; the pure mathematical theories, by means of which men, who were in general of in

ferior talents, both as physicians and geometers, pretended to explain the functions of the different organs of the body; the hydraulic theories that succeeded, and which served as the foundation of so many erroneous calculations with regard to the circulation of the blood and other fluids; and, lastly, the mechanical views that were broached respecting the laws of motion, and their influence on the phenomena of life, or respecting the advantages which may be derived from an acquaintance with them in the illustration of these phenomena; all began to attract very general attention, when there appeared a new professor, who was destined to effect a real revolution in the science of medicine.

The professor here alluded to is the celebrated Boerhaave; but before we engage in a slight disquisition respecting the merits of this individual, and the peculiarities of his theory, we are called upon to introduce to our readers' notice an English physician, who, by one leading practical institute, and by the general substitution of good sense, and untrammelled observation, for systematic conceit, and hypothetic inference, did more for the science of medicine than had been effected by scholastic and theoretic principles for ages. It will have been seen that even Hippocrates himself (who has justly been called the physician of nature, in contrast with others who seemed to demand that nature should accommodate herself to their postulata, and not them to nature), it will have been observed, we say, that even in the writings of Hippocrates the notion of a concoction of humors, previous to their expulsion, is defended as a principle of practical regulation. By others this principle was carried still further into practice; and, at the time when Sydenham made his appearance in the world of medicine, heating alexipharmic materials were forced down the throats of the sick, under the assumption now referred to, without measure, and without mercy-without mercy, we say; for the sufferings, and manifestations of sufferings, of the sick, were disregarded among the clamorous calls of a prevailing system thus founded in misconception, and acted upon in cruelty.

185. Sydenham at once saw the error of this plan of treatment, and boldly proposed and carried into effect a reformation, which, as we have above intimated, was attended with practical good of the most unequivocal and extensive kind. But we are here again tempted to make a long extract from an author upon whom we have already made large demands, and whom we always find much satisfaction in quoting; in the present instance the testimony of an enlightened foreigner, given with so much propriety of feeling and freedom from all sort of prejudice, upon the merits of our own countrymen, will be received with the approbation due to its value.

186. When Sydenham (says Cabanis), appeared in England, the science of physic still retained its scholastic form. The progress of the other branches of knowledge had hitherto exerted only a prejudicial influence upon it; and the general spirit of observation was almost entirely unknown. Sydenham, after a short course of study, assisted by a little reading, but gui'ed

chieffy by the impulse of a happy genius, undertook to bring back the practice of the art to the path of experience. With the prevailing theories of the time he was but imperfectly acquainted; but this circumstance was perhaps more favorable to his labors, as it could never be embarrassing to his self-love, and as he would find less difficulty in following the footsteps of nature. Among the number of his friends was the illustrious Locke, to whom we are indebted, if not for the first principles of a philosophical method of enquiry, at least for the first demonstration of the fundamental truths on which they are founded. The friendship of such a man sufficiently indicates the disposition of mind of the person who cultivates it, and serves, as it were, for its standard comparison. We can therefore scarcely doubt that the counsels of the philosopher must have greatly contributed to the success of the physician, who indeed acknowledges it himself with candor.

187. Sydenham attacked with the irresistible arms of experience several destructive prejudices which at that time prevailed. The chemists, for instance, had introduced into medicine the indiscriminate use of cordials and of ardent or volatile spirits. In acute diseases, in particular, the abuse of these remedies was very great. Sydenham proved that, in such cases, they were almost always injurious, but especially at the commencement of the disorder. The small pox and other acute cutaneous eruptions were treated by sudorifics alone. Sydenham demonstrated that this mode of practice had been more fatal to mankind than a long succession of destructive wars. His Treatise on the Gout has been generally regarded as a master-piece of description ; it is indeed the most perfect account of this disease which we possess; not that this malady always presents itself in the manner in which it is described, but because we can conceive nothing more accurate or ingenious than the plan of observation which he there lays down.

188. Hippocrates, in his Epidemics, had sketched the outlines of a system of physic as extensive as it was original. During several ages his ideas had remained in a manner dormant. Baillou, a Parisian professor, in the sixteenth century, appropriated them to himself, and extended them: not indeed as a man of genius, for he was not such, but at least as an attentive observer, and skilful practitioner. He was even led to consider them in several new points of view.

189. Sydenham, without having any knowledge of Baillou, perhaps even without having read Hippocrates, was led into the same path by observation alone. He pursued it with still greater success; and in this his chief glory consists. It is only since his time that we have become thoroughly acquainted with those general variations to which the character of epidemic diseases are liable; witl. the relations they bear to each other; and their connexion with the different apparent changes of the atmosphere, or their independence of these changes, which is often very apparent; with the influence they exert on sporadic or local disorders; and, fastly, with the manner in which their succession is

when Brown, in some measure like a second Paracelsus, started into notice-we say like a second Paracelsus, because he boldly and at once avowed his unqualified dissent from all that had gone before him, and not only opposed but ridiculed and contemned all the attempts which hitherto had been made to combine into one systematic whole the principles of life and the causes of disease.

197. Deviation from the state of health, in which the morbid state consists, is not, says Brown, either repletion or inanition, or changes in the quantities of the fluids, whether of an alkaline or of an acid nature; or the introduction of foreign matters into the system; or a change of figure in the extreme particles; or a disproportion in the distribution of the blood; or an increase or decrease of the powers of the heart and vessels as regulating the circulation; or a rational principle governing the actions of the body; or an alteration in the extreme particles as being of too large or too small a size; or an alteration of the pores as being too narrow or too capacious; or a constriction of the superficial vessels from cold; or a spasm of these vessels producing a reaction, as it is called, of the heart and interior vessels; or any thing that any person has yet thought of respecting the cause and nature of the morbid state. On the contrary, health and disease are the same state, depending on the same cause, that is excitement, varying only in degree; and the powers producing both are the same, sometimes acting with a proper degree of force, at other times either with too much or too little the whole and sole province of a physician is not to look for morbid states and remedies which have no existence, but to consider the deviation of excitement from the healthy standard, in order to remove it by proper

means.

198. It will be readily seen, says a modern writer, that this subordination of every thing in the living economy to the leading and masterprinciple of excitement, constitutes the essence of Brunonian pathology and practice. A subordination that may be illustrated by adducing one or two examples. Suppose an individual to be affected with the disorder called diabetes, which disorder is constituted mainly of an altered quantity and condition of the urinary secretion; at least, that is one of its most prominent characteristics. The philosophy of Brown would teach us that the general systematic derangement, by which the malady is constituted, is the only matter of consequence to attend to; and could we but bring the excitement, that is the healthy actions of the system, to a proper balance and bearing, every thing else would fall by consequence into regularity and order; the functions of the kidneys would be restored to their wonted integrity, and health would take place of disease. 199. Again, suppose that a man falls down in an apoplectic fit, he dies, and you examine the condition of the brain; whether it is or is not laden with an undue quantity of blood and serum; whether some of the blood-vessels of the organ have or have not given way; the main circumstance to be regarded, in appreciating the nature of the affection, is the extent to which the

excitement has been implicated; and the only effectual way of warding off attacks of apoplexy, or even of remedying them when they are remediable, is not to set about emptying the bloodvessels, which is a debilitating process, and calculated to be destructive of its own design; but to aid the sinking and restore the lost excitement. To cure disorder, upon the Boerhaavian hypothesis, is to correct the acrimony of the fluids, or diminish their lentor, or to open the pores of the body for their exit. The Cullenian would say, Take off spasm from extreme vessels and excite, repress, or regulate reaction; while Brown's disciples would say, Adjust and adapt the excitability to the powers which excite, and you need not trouble yourself about any thing further.

200. This Brunonian doctrine of excitability was modified and complicated by Dr. Darwin into four distinct divisions. All diseases, says this last systematist, originate in the exuberance, deficiency, or retrograde action of the faculties of the sensorium as their proximate cause, and consist in the disordered motions of the fibres of the body, as the proximate effect of the exertions of those disordered faculties.

201. The sensorium possesses four distinct powers or faculties, which are occasionally exerted, and produce all the motions of the fibrous part of the body. These are the faculties of producing fibrous motions in consequence of irritation, which is excited by external bodies; in consequence of sensation which is excited by pleasure or pain; in consequence of volition, which is excited by desire or exertion; and in consequence of association, which is excited by other fibrous motions. We are hence supplied with four natural classes of diseases, derived from their proximate causes, which we shall term those of irritation, those of sensation, those of volition, and those of association.

202. Darwin's propositions and principia may be considered the last to have been organised into a body of systematic doctrine. Since his time attempts to generalize have been of rather a different cast: thus, instead of uniting physic with metaphysic and aiming to reduce vital causation, and deranged action to one leading and generally applicable law, in the same manner that gravitation is applied to the phenomena exhibited by inanimate matter; and which attempts, by the way, have all proved nugatory; the endeavours of recent systematists have rather been those of localising disease, or of aiming to prove that affections of this or that part, or primary derangement of one or another organ, are the main springs of general perturbation. Some of these theorists, evincing a disposition to place this fons et origo malorum in the liver, some in the brain, some in the stomach, and some in the fine membrane which secretes mucus and lines internal cavities. And it is a curious fact that the organic theories, if so they may be termed, have seemed to originate in the downfal of the Brunonian assumption of mere general_excitement; or rather when it was perceived, as it soon.must have been perceived, that these principles were too comprehensive and sweeping to be applied to the complicated organisation of the

hiving body, the contrary principles, from the tendency there is in the human mind to reacting extremes, came into play; and, as it has been expressed, from no organ it came to be all organ. And there has been another manifestation of opposing principle in the more recent fashion of placing every thing connected with morbid being to the account of the blood-vessels, which is in contradistinction to the nervous theories of the solidists and animists who have just passed by; so it will be seen that the spirit of system, though curbed and crippled by the good sense of modern times, has not yet totally disappeared. Indeed, theory, after all, must more or less influence practice, even among the least disposed to abstract reasoning. With some,' says a writer whom we have already quoted, the notion of theory, as applied to the art of healing diseases, is considered to be altogether nugatory; and it must be admitted that much of medical doctrine and dicta has prevailed at different times without proving materially influential upon practical indications. I am ready, moreover, to admit, that a large proportion of therapeutic endeavour is conducted, more especially in the present day, under the guidance of an empirical good sense, without reference to the institutes of determined systematists; but still it will be found that the most decided oppositionist to partial views, and particular creeds, is in a greater cr less degree influenced in his feelings, and directed in his habits, by the prevailing theories of the times. No one surely will deny that up to the present moment many sensible and unsystematic practitioners are pushing at the liver, and prescribing blue pill, or correcting the chylopoietics, or emptying the blood vessels, or battling at congestion, or thinking about morbid condition of mucous membranes; who, had they been living in the days of Boerhaave, of Hoffman, or of Cullen, would have been acting under the notion of deobstruent agency; have been busily employed in attempts to restore the balance of nervous and fibrous excitation, or in finding out the best methods of resolving spasm, and regulating reaction.' The writer might have added that, had his supposed practitioner been the practitioner of times preceding Sydenham, he might have been waiting for the coction of humors, and permitting the disorder to proceed without interruption till this imaginary process was complete; or he would have been adding irritation to too much already present, under the idea of forcibly expelling humors. Another difference in these cases would not, as it is remarked, be merely in terminology; the medicaments and actual modes of management would also differ; so that it is of some consequence, to say the least, for us to look well to the correctness of propounded principia before we permit them to become either in whole or part parcel of the mind.' And it further behoves us to look well towards the correction of another, but opposite tendency, viz. that which refuses to receive any of the good of system, inasmuch as it is mixed with evil. To think is to systematise, and a process of thought must ever precede all acts that are not instinctive or involuntary. It is impossible to observe the various appearances in nature without remarking certain circumstances

in which they agree; to remark these circumstances is to arrange the similar appearances. It is thus impossible not to systematise; and hence the question should be, not whether systems be useful, but to what extent, and in what mode they can be most usefully formed.'

203. There ought of course to be as little as possible assumed; or rather, the assumption having been once made, its legitimacy ought not to be blindly and obstinately maintained; but, on the contrary, it should be tried by the severest tests of affiliation. Thus, if we find post mortem appearances subsequent to a certain series of symptoms, we may register or arrange the two circumstances under one head of cause and effect; and pleasure may arise from having detected a connexion which has escaped the sagacity of others; but to this supposed discovery such a partiality must not be conceived, as that its cause must be defended against subsequent development of truth. And it is precisely from this point whence all the errors of systematists commence and proceed. When we talk of congested veins, inflamed arteries, disordered tissues, chylopoietic disturbances, and hepatic derangements, as influencing the whole series of organic movements; is not one link only in the chain of causation open to our perception, while the remainder are among the invisible or dimly seen? Are we rot apt to overlook the impelling, in our eagerness to grasp at the impelled? In other words, do not we seize hold of one or two striking facts in morbid manifestation, and, hurrying away with them to our closets, mould them into a mass, and eventually throw them out upon the world as presents from nature, whereas they are in reality half the products of our own manufacturing ingenuity? Thus, for a time, the most daring and novel become the most accredited propositions; but as soon as their charm of novelty is gone by, and their propounders are laid in the silent grave, the adventitious separates itself from the real, and the dross is discovered to bear an immeasurably large proportion to the intrinsic of the doctrine.

204. Brown would have effected an abundance of good had he been content to have ridiculed the metaphysical abstractions, or physical absurdities, of preceding systematists; but his failure consisted in attempting another abstraction, in lieu of those he had hurled to the dust; and an abstraction which was still more mischievous in its bearings than those that had gone before; inasmuch as that part of it which was illegitimate and bad was more positively and practically so than its predecessors. It is indeed frightful to contemplate the evil that must have resulted from the determined application of his sweeping dogma, which it is surprising was not sooner brought to the ad absurdum test of trial as to its rectitude. But even in this system, degraded as it at present is, a great deal of actual good may be discerned; and a great deal, moreover, of the indirect and direct occasion of those theories that are at present the order of the day.

205. To this circumstance we have already adverted; and we have in some measure anticipated, in the latter clauses of this historical sketch, the second head proposed for disquisition,