The name appears in Florentine chronicles as early as the close of the 12th century, although only casually mentioned in connexion with various offices of the republic. The first of the family to be a distinct figure in history was Salvestro dei Medici, who, in the year 1378, took an active part in the revolt of the Ciompi—so-called because it was led by a wool-carder {ci<ym,po) y one Michele di Lando, and because the chief share in it was taken by the populace, who held the reins of government for some time, and sought to obtain extended political rights. But, although Michele di Lando was the nominal chief of the revolt, Salvestro dei Medici was its real leader. The latter, although a member of the greater guilds, had joined the lesser and sought to be at their head, in order to lay the foundation of his own power and that of his kindred by attacking the Albizzi, who were the leading men of the greater guilds. The victory of the Ciompi, however, was brief, for the excesses of the lower classes brought about a reaction, in which they were crushed, and Michele di Lando sent into banishment. Nevertheless the lesser guilds had gained some ground by this riot, and Salvestro dei Medici the great popularity at which he had aimed. His policy during that period had traced the sole possible road to power in liberty-loving Florence. And this was the road henceforth pursued by the Medici.

On Salvestro’s death in 1388 the Albizzi repossessed themselves of the government, and conducted the wars of the republic. Vieri dei Medici, who seems to have been the next head of the family, understanding the temper of the times, abstained from becoming a popular leader, and left it to his successors to prosecute the task under easier conditions. Then, in the person of Giovanni, son of Bicci dei Medici (1360—1429), another branch of the family arose, and became from that time forward its representative branch. Indeed this Giovanni may be considered the actual founder of Medicean greatness. He took little part in political affairs, but realized an immense fortune by trade,—establishing banks in Italy and abroad, which in his successors’ hands became the most efficient engines of political power. The council of Constance (1414- 1418) enabled Giovanni dei Medici to realize enormous profits. Besides, like his ancestor Salvestro, he was a constant supporter of the lesser guilds in Florence. Historians record his frequent resistance to the Albizzi when they sought to oppress the people with heavier taxation, and his endeavours to cause the chief weight to fall upon the richer classes. For this reason he was in favour of the so-called law of catasto, which, by assessing the property of every citizen, prevented those in power from arbitrarily imposing taxes that unjustly burdened the people. In this way, and by liberal loans of money to all who were in need of it, he gained a reputation that was practically the foundation-stone of the grand family edifice. Giovanni dei Medici died in 1429 leaving two sons, Cosimo (1389— 1464) and Lorenzo (1395-1440). From the former proceeded the branch that held absolute sway for many generations over the nominal republic of Florence, and gave to Italy popes like Leo X. and Clement VII. On the extinction of this elder line in the 16th century, the younger branch derived from Lorenzo, Cosimo’s brother, seemed to acquire new life, and for two centuries supplied grand-dukes to Tuscany. Cosimo, surnamed Cosimo the Elder, to distinguish him from the many others bearing the same name, and honoured after his death by the title of Pater patriae, first succeeded in solving the strange problem of becoming absolute ruler of a republic that was keenly jealous of its liberty, without holding any fixed office, without suppressing any previous form of government, and always preserving the appearance and demeanour of a private citizen. Born in 1389, he had already reached the age of forty at the time of his father’s death. He had a certain amount of literary culture, and throughout his life showed much taste and an earnest love both for letters and art. But his father had mainly trained him to commerce, for which he had a special liking and aptitude. In fact he was devoted to business to the day of his death, and like his forefathers derived pecuniary advantage from his friendly relations with the papal court. He accompanied Pope John XXIII. to the council of Constance, transacted a vast amount of business in that city, and made very large gains. Hethen travelled in Germany, and after his return to Florence discharged several ambassadorial missions. At the death of his father he was possessed of a vast fortune and an extended experience, and inherited the leadership of the opposition to the then dominant party of the greater guilds headed by Rinaldo degli Albizzi, Palla Strozzi, and Niccolo da Hzzano. Of gentle and kindly manners, generous in lending and even in giving money whenever he could gain popularity by that means, at critical moments he frequently came to the succour of the Government itself. He was very dexterous in turning his private liberalities to account for the increase of his political prestige, and showed no less acumen and still fewer scruples in making use of his political prestige for purposes of pecuniary profit. Indeed, whenever his own interests were at stake, he showed himself capable of positive villainy, although this was always tempered by calculation. Cosimo proved his skill in these knavish arts during the war between Florence and Lucca. He had joined the Albizzi in urging on this war, and many writers assert that he turned it to much pecuniary advantage by means of loans to the Government and other banking operations. When, however, military affairs went badly, Cosimo joined the discontented populace in invectives against the war and those who had conducted it. This won him an enormous increase of popularity, but the hatred of the Albizzi and their friends augmented in equal degree, and a conflict became inevitable. The Albizzi, who were far more impetuous and impatient than Cosimo, were now bent upon revenge. In 1433 one of their own friends, Bernardo Guadagni, was elected gonfalonier, and thereupon Cosimo dei Medici was called to the palace and summarily imprisoned in the tower. A general assembly of the people was convoked and a “balia” chosen, which changed the Government and sent Cosimo into exile. Undoubtedly the Albizzi party would have preferred a heavier sentence, but they did not dare to attempt their enemy’s life, being well aware of the great number of his adherents. Cosimo had some apprehension that he might be poisoned in prison, but Federigo dei Malavolti, captain of the palace guard, showed him the utmost kindness, and, in order to soothe his fears, voluntarily shared his meals. On the 3d October the prisoner was sent to Padua, his allotted place of exile.

The Albizzi speedily saw that they had done either too much or too little. While seeking to keep the government entirely in their own hands, they beheld the continual growth of the Medici party. When it was necessary to make a campaign in Romagna against the mercenary captains commanding the forces of the duke of Milan, it was plainly seen that in banishing Cosimo the republic had lost the only citizen banker in a position to assist it with considerable loans. The Florentines were defeated by Piccinino in 1434, and this event greatly increased the public exasperation against the Albizzi. Meanwhile Cosimo, who had gone to Padua as a private individual, was entertained there like a prince. Then, being permitted to transfer his residence to Venice, he entered on a course of lavish expenditure. He was overwhelmed with letters and appeals from Florence. Finally, on the 1st of September 1434, a signory was elected composed of his friends, and his recall was decreed. Rinaldo degli Albizzi determined to oppose it by force, and rushed to the Piazza with a band of armed men; but his attempt failed, and he left the country to return no more. The Medici were now reinstated in all their former dignities and honours, and Cosimo, on the evening of September 6th, rode past the deserted mansions of the Albizzi and re-entered his own dwelling after an exile of a year. For three centuries, dating from that moment, the whole history of Florence was connected witlι that of the house of Medici.

Cosimo’s first thought was to secure himself against all future risk of removal from Florence, and accordingly he drove the most powerful citizens into exile to all parts of Italy. Nor did he spare even his former political adversary, Palla Strozzi, although the latter had been favourable to him during the recent changes. His rigour in this particular case was universally censured, but Cosimo would tolerate no rivals in the city, and was resolved to abase the great families and establish his power by the support of the lower classes. He was accustomed to say that states could not be ruled by paternosters. Still, when cruelty seemed requisite, be always contrived that the chief odium of it should fall upon others. When Neri Capponi, the valiant soldier and able diplomatist, gained great public favour by his military prowess, and his influence was further increased by the friendship of Baldaccio d’Anghiari, captain of the infantry, Cosimo resolved to weaken his position by indirect means. Accordingly, when in 1441 a partisan of the Medici was elected gonfalonier, Baldaccio was instantly summoned to the palace, imprisoned, murdered, and his body hurled from the window. No one could actually fix this crime upon Cosimo, but the majority believed that he had thus contrived to rid himself of one enemy and cripple another without showing his hand. It was impossible for Cosimo openly to assume the position of tyrant of Florence, nor was it worth his while to become gonfalonier, since the term of office only lasted two months. It was necessary to discover some other way without resorting to violence; he accordingly employed what were then designated “civil methods.” lie managed to attain his object by means of the “balte.” These magistracies, which were generally renewed every five years, placed in the ballot bags the names of the candidates from whom the signory and other chief magistrates were to be chosen. As soon as a “balia” favourable to Cosimo was formed, he was assured for five years of having the government in the hands of men devoted to his interests. He had comprehended that the art of politics depended rather upon individuals than institutions, and that he who ruled men could also dictate laws. His foreign policy was no less astute. His great wealth enabled him to supply money not only to private individuals, but even to foreign potentates. Philippe de Comines tells us that Cosimo frequently furnished Edward IV. of England with sums amounting to many hundred thousand florins. When Tommaso Parentucelli was still a cardinal, and in needy circumstances, Cosimo made him considerable loans without demanding guarantees of payment. On the cardinal’s accession to the tiara as Nicholas V. he was naturally very well disposed towards Cosimo, and employed the Medici bank in Rome in all the affairs of the curia, which brought immense profits to the house. At the time when Francesco Sforza was striving for the lordship of Milan, Cosimo foresaw his approaching triumph, showed him great friendship, and aided him with large sums of money. Accordingly, when Sforza became lord of Milan, Cosimo’s power was doubled. Without the title of prince, this merchant showed royal generosity in his expenditure for the promotion of letters and the fine arts. Numerous edifices were raised and public works accomplished with his purse. Besides his palace in the city, he constructed noble villas at Careggi, Fiesole, and other places. He built the basilica of Fiesole, and that of St Lorenzo in Florence, and enlarged the church and monastery of St Mark. Even in distant Jerusalem he endowed a hospice for the use of pilgrims. The artists of the day comprised men like Donatello, Brunelleschi, Ghiberti, Luca della Robbia, and many others, and Cosimo’s magnificent commissions not only developed their powers but stimulated other men of wealth to the patronage of art. Without being a scholar, Cosimo had a genuine taste for letters, and gave them much and efficient patronage. He purchased many Greek and Latin manuscripts; he opened the first public library at St Mark’s at his own expense, and founded another in the abbey of Fiesole. The Greek refugees from Constantinople found a constant welcome in his palace. During the council of Florence (1439-1442), Gemisthus Pletho spoke to him with enthusiasm of the Platonic philosophy. Cosimo was so deeply attracted by the theme that he decided to have the young Marsilio Ficino trained in philosophy and Greek learning in order to make a Latin translation of the complete works of Plato. And thus a version was produced that is still considered one of the best extant, and that Platonic academy was founded which led to such important results in the history of Italian philosophy and letters. On the 1st of August 1464 Cosimo breathed his last, at the age of seventy-five, while engaged in listening to one of Plato’s dialogues.

The concluding years of his life had been years of little happiness for Florence. Being old and infirm, he had left the government to the management of his friends, among whom Luca Pitti was one of the more powerful, and they had ruled with disorder, corruption, and cruelty. The lordship of Florence accordingly did not pass without some difficulty and danger into the hands of Piero, surnamed the Gouty, Cosimo’s only surviving legitimate son. Afflicted by gout, and so terribly crippled that he was often only able to use his tongue, the new ruler soon discovered that a plot was ou foot to overthrow his power. However, showing far more courage than he was supposed to possess, he had himself borne on a litter from his villa to Florence, defeated his enemies’ designs, and firmly re-established his authority. But his success may be mainly attributed to the enormous prestige bequeathed by Cosimo to his posterity. Piero died at the end of five years’ reign, on the 3d December 1469, leaving two sons, Lorenzo (1449-92) and Giuliano (1453-78). The younger, the gentler and less ambitious of the pair, was, as we shall presently see, quickly removed from the world. Lorenzo, on the contrary, at once seized the reins of state with a firm grasp, and was, chronologically, the second of the great men bestowed upon Italy by the house of Medici. In literary talent he was immensely superior to Cosimo, but greatly his inferior in the copduct of the commercial affairs of the house, for which he had neither aptitude nor inclination. Jn politics he had nobler conceptions and higher ambitions, but he was more easily carried away by his passions, less prudent in his revenge, and more disposed to tyranny. He had studied letters from his earliest years under the guidance of Ficino and other leading literati of the day, who were constant habitues of the Medici palace. At the age of eighteen he visited the different courts of Italy in order to gain experience of the world and mankind. At his father’s death he was only twenty-one years old, but instantly showed his determination to govern Florence with greater despotism than his father or grandfather. He speedily resorted to the system of the “balie,” and was very dexterous in causing the first to be chosen to suit his purpose. He then proceeded to humiliate the great families and exalt those of little account, and this was the policy he constantly pursued. His younger brother Giuliano, being of a mild and yielding disposition, had only a nominal share in the government.

Lorenzo’s policy was not exempt from danger, but, although prosecuted with less caution, it was still the old astute and fortunate policy initiated by Cosimo. But the grandson bestowed no care upon his commercial interests, although squandering his fortune with far greater lavishness. Accordingly he was sometimes driven to help himself from the public purse without ever being able to assist it as Cosimo had done. All this excited blame and enmity against him, while his greed in the matter of the alum mines of Volterra, and the subsequent sack of that unhappy city, were crimes for which there was no excuse. Among his worst enemies were the Pazzi, and, as they formed a very powerful clan, he sought their ruin by competing with them even in business transactions. They were just on the point of inheriting the large property of Giovanni Borromeo when, in order to prevent this, Lorenzo hurriedly caused a law to be passed that altered the right of succession. The hatred of the Pazzi was thereby exasperated to fury. And in addition to these things there ensued a desperate quarrel with Pope Sixtus IV., a man of very impetuous temper, who, on endeavouring to erect a state on the frontiers of the Florentine republic for the benefit of his nephews, found a determined and successful opponent in Lorenzo. Consequently the Pazzi and Archbishop Salviati, another enemy of Lorenzo, aided by the nephews of the pontiff, who was himself acquainted with the whole matter, determined to put an end to the family.

On the 26th April 1478, while Giuliano and Lorenzo were attending high mass in the cathedral of Florence, the former was mortally stabbed by conspirators, but the latter was able to beat back his assailants and escape into the sacristy. His life saved; and, no longer having to share the government with a brother, Lorenzo profited by the opportunity to wreak cruel vengeance upon his foes. Several of the Pazzi and their followers were hanged from the palace windows; others were hacked to pieces, dragged through the streets, and cast into the Arno, while a great many more were condemned to death or sent into exile. Lorenzo seemed willing and able to become a tyrant. But he stopped short of this point. He knew the temper of the city, and had also to look to fresh dangers threatening him from without. The pope had excommunicated him, put Florence under an interdict, and, being seconded by the Neapolitan king, made furious war against the republic. These hostilities speedily assumed alarming proportions, and the Florentines began to tire of submitting to so many hardships in order to support the yoke of a fellow-citizen. Lorenzo’s hold over Florence seemed endangered. But he did not lose heart, and, on the contrary, rose superior to the difficulties by which he was encompassed. He boldly journeyed to Naples, to the court of King Ferdinand of Aragon, who was reputed to be as treacherous as he was cruel, and succeeded in obtaining from him an honourable peace, that soon led to a reconciliation with Sixtus. Thus at last Lorenzo found himself complete master of Florence, and was in a position to turn his power to account. But, as the “balte” changed every five years, it was always requisite, in order to retain his supremacy, that he should be prepared to renew the usual manoeuvre at the close of that term and have another elected equally favourable to his aims. This was often a difficult achievement, and Lorenzo showed much dexterity in overcoming all obstacles. In 1480 he compassed the institution of a new council of seventy, which was practically a permanent ii balia” with extended powers, inasmuch as it not only elected the chief magistrates, but had also the administration of numerous state affairs. But, this permanent council of his own devoted adherents once formed, his security was firmly established. By this means, the chroniclers tell us, “liberty was buried,” but the chief affairs of the state were always conducted by intelligent and experienced men, who promoted the public prosperity. Florence was still called a republic; the old institutions were still preserved, if only in name. Lorenzo was absolute lord of all, and virtually a tyrant. His immorality was scandalous; he kept an...

Disease is the correlative of health, and the word is not capable of a more penetrating definition. From the time of Galen, however, it has been usual to speak of the life of the body either as proceeding in accordance with nature (κατά φvσι,v, secundum nal·uram) or as overstepping the bounds of nature (παρά φvσιv, praeter naturam'). Taking disease to be a deflexion from the line of health, the first requisite of medicine is an extensive and intimate acquaintance with the norm of the body. The normal condition of the body is capable of being determined without ambiguity; it is the absence from its structures and functions of every disease hitherto known. The structure and functions of the body form the subject of anatomy and physiology.

Physiology is, strictly speaking, the science of that which is κατά φvσιv, or secundum naturam, and it is usual to say that the theory of diseases is based upon physiology. But, although all that was implied in the Hippocratic term φvσις (natιιra) may be claimed as the subject-matter of physiology, yet, in the ordinary connotation of the term, physiology divides the empire with anatomy. To physiology the functions of the body are usually assigned, and to anatomy its form and structure. But, as a matter of fact, the structures and functions of the organism are not separable; structure is correlated to function, whether active, dormant, or extinguished, and in like manner function is the twin notion of structure. In the ultimate analysis neither term means anything without the other, and both together mean life. It is owing mostly to its name that physiology is supposed to have a preponderant interest for the theory of disease; the word anatomy is not well adapted to carry its own half of the structure* and-function dualism. Both in the historical development and in the logical connotation, anatomy is as much associated with the living and moving body as physiology itself; but its etymology has always been against it, and it has become more and more difficult to retain for anatomy anything beyond the technicalities of the dissecting-room. The subject of general anatomy has for the most part disappeared from modern text-books, its place being taken by histology, which deals with the minute structure of the simple tissues, and, in a wider acceptation, with the finer anatomy of all the organs and parts of the body. Histology, like anatomy, has had a somewhat technical or descriptive rôle assigned to it; and it is now mainly under physiology that the processes, activities, or living mechanisms of the body fall to be considered. The development of the body as a whole, and of its several tissues and organs, forms the subject of embryology; many of the physiological types of diseased processes, especially the cellular, are discoverable in the embryological period. For the-period of development, no arbitrary separation has been attempted hitherto between structure and function, and embryology is, in theory at least, as much physiological as anatomical. The development of function is a legitimate and even desirable subject of scientific study, and a more distinctive place is probably awaiting it in the future; but so indissoluble does the union of structure and function present itself in the period of genesis and growth that the function has hardly as yet come to be abstracted from the structure, or the structure from the function.

The theory of disease rests, therefore, upon physiology, with its more or less technical adjuncts. Pathology is all that physiology is, with the engrossing and difficult element of perturbation, deflexion, or shortcoming added. By virtue of this element of deviation from the line of health, pathology is a discipline apart, with an abundant literature of its own, and with separate academical institutes and chairs. But pathology is also a discipline apart by virtue of concepts proper to itself. A great part of the theory of disease deals with changes or defects of structure and perturbations or failings of function, which may be intricate or difficult to analyse, but are still well within sight of the line of health. Such are the common diseases of the organs and systems—the inflammations, catarrhs, degenerations, hypertrophies, and functional derangements without lesion of the respiratory, circulatory, nervous, genito-urinary, locomotor, and cutaneous systems. Constitutional or general diseases belong also to the province of perturbations from the physiological course,—such diseases as chlorosis, leukaemia, diabetes, gout, rheumatism, scurvy, rickets, Addison’s disease, exophthalmic goitre, and the febrile state. Again, congenital deficiencies or malformations, non-cancerous tumours, and the repairing of injuries exemplify no other laws than those of development and growth.

But with those examples the catalogue of physiological diseases is exhausted. We are left with a vast residue of diseases, which have always bulked largely in the popular mind, and have carried the most terrible associations with them. Such are the pestilences or diseases of peoples: — the plague, sweating sickness, cholera, yellow fever, typhus fever, relapsing fever, typhoid fever, diphtheria, small-pox, measles, scarlet fever, influenza, dengue. Such also are the cancers, consumptions, leprosies, and other loathsome infections. This enormous residue is more than the half of disease, and the definition of disease or the scheme of pathology is brought to a test in finding room within its scientific categories for such maladies as those. The popular imagination in all countries has personified them; medicine in its metaphysical period has regarded them as entities or things in themselves; and it remains to be seen in what way or to what extent medicine in its scientific period will bring them within the category of perturbations of the physiological life.

In considering, for a moment, where to place cancer in the pathological scheme, we shall arrive at a point of view from which the relation of the acute and chronic infections (or contagions) to diseases of the physiological order may be contemplated at least provisionally. Taking cancers, in a generic sense, to mean tumours that have acquired or are possessed of malignancy, we find that such tumours have many points in common with simple tumours,—that they have grown out of the tissues of particular organs or parts under particular (functional) circumstances, and that they may, in general terms, be traced back to that point at which they left the line of health (see Pathology). The tracing back of tumours along the physiological track is often difficult and laborious; but there is no tumour of the body whose origins are not at length discoverable within the limits of physiological action. That which makes any tumour a cancer is something over and beyond; it is a remarkable acquired property of reproducing its structure in manifold copies, or of infecting the organism of which it is itself a part. The tumour thus becomes a semi-independent power within the body; it may be said, in a political figure, to have acquired autonomy, or to have become imperium in impei'io. A due consideration of such a phenomenon as the infectiveness or cancerousness of some tumours will satisfy one that there are concepts in pathology which carry the investigator entirely beyond physiological bounds or out of sight of the line of health, which bring him face to face with the notion of a disease as a thing in itself, and which thus constitute a peculiar subject-matter. There is nothing that we know among biological phenomena altogether analogous to the semiindependence which an integral part of the body, or condition of the body, manifests towards the organism as a whole, and that, too, strictly in respect of its acquired devious or rebellious habit. The familiar definition of disease, morbus est vita praeter naturam, which embodies the notion of divergence from the line of health, makes no provision for an acquired autonomy of a morbid state; and that definition has to be supplemented by another, which will recognize the possibility of a disease becoming a thing in itself. The old definition of Van Helmont, morbus est ens reale subsistens in corpore, appears to satisfy the requirement; but that definition, although it grew out of the phenomena of disease as observed in fevers, was made too general, and has now associations that are too exclusively ontological and metaphysical. The supplementary definition should be as far as possible in the terms of the principal definition; and we shall provide best in the pathological scheme for such a disease as cancer if, in addition to tho formula morbus est vita prseter naturam, we construct a secondary formula, morbus est vivum in vivo.

The notion of autonomy acquired by a morbid state implies, naturally, a pre-autonomous stage of the disease, which had been a mere perturbation of the norm of tho body, capable of being measured by the physiological standard. The autonomous stage and the pre-autonomous stage, which may be demonstrated, in individual cases, for cancers, are a philosophical necessity for all other infective diseases that are marked by morphological features, or by structural characters rooted in and growing out of the proper textures of the body. Thus the peculiar skin eruption of small-pox, which is communicable from person to person, along with a distinctive course of fever, must have had pre-autonomous antecedents (not altogether historically vague) in certain casual conditions of the skin and associated constitutional disturbance, which had recurred and become inveterate, and had so attained to a degree of individuality or a point of autonomy at which they began to be propagated as an organic unit. Again, a second group of infections, exemplified by glanders, bovine tubercle, and syphilis, are rooted in deeper textural processes, which must have been at one time (and may still be) set up by the casual operation of ordinary causes, and at length became the occasion of infective mimicry. It is not so easy to picture (and it is not difficult, with a modern dominant school, to ignore) the casual morbid conditions or ordinary physiological perturbations out of which powerful infections like cholera, typhoid fever, or yellow fever may have arisen; but if the rise and consolidation of their autonomy be a subtle or even untraceable history, yet there are diseases, such as dysentery and erysipelas, which are apt to occur both as casual or spontaneous conditions and as specific infections side by side. Ophthalmia is an example of a purulent catarrh which is constantly arising de novo in Egypt from local causes in a non4nfective manner, and yet has become, on at least one memorable occasion, a powerful and widespread infection for British troops returning from that country and for the home garrisons for many years subsequently. Infective pneumonia in cattle, and more rarely in man, is an analogous case. In such an episode we observe the actual rise of the disease-autonomy. Again, all the infective diseases have degrees of intensity, at one extreme of which there must occur the vanishing point of their infective property; and those gradations of infectiveness are nowhere more noticeable than in the relation of cholera to choleraic diarrhoea. Further, the remarkable group of climatic fevers are not communicable from person to person (see Malakia) ; in that respect, and for the reason that the liability of the patient is anything but exhausted by one attack, they are examples of fevers without autonomy. There is not one of the infections that may not be profitably studied from the point of view of its autonomy, and of its more or less obscure pre-autonomous stage. That is a point of view from which even the pestilences and other specific diseases may be regarded as coming within the physiological categories. The large residue of diseases, which are more than perturbations of the physiological life, may still be joined by natural descent to the class of simple perturbations, if we can show for them how their autonomy was acquired, or what was their origin as diseasespecies.

There is an established place in the history of medicine, and there ought therefore to be room in the definition of <lisease, for epidemic outbreaks of purely psychical diseased states, such as the dancing madness (Tanzwuth), and the boys’ crusades; the epidemic diffusion of such morbid states is best approached from the point of view of an acquired autonomy (fixed idea) and an infective mimicry.

The physiological definition of disease, morbus est vita prater naturam, affords no place for parasitic diseases. However, the supplementary formula that has been proposed to meet the case of diseases existing autonomously in the body, morbus est vivum in vivo, will meet the case of parasitic diseases also. According to many pathologists of the present generation, the whole class of pestilences, fevers, and specific infections generally are caused by certain species of minute parasites invading the body; according to one form of that hypothesis the distinctive characters or specific marks (morphological and other) of those diseases are neither more nor less than the appropriate effects wrought upon the textures and fluids of the body by the respective species of parasites. In this way the great group of infective diseases, which are apt to be the stumbling-block of a scientific definition and logical scheme of disease, are easily disposed of by placing them beside the otherwise insignificant group of parasitic diseases. Whether all or any of those diseases are due in a sense to the invasion of parasites, or wholly caused by parasites, are questions that naturally fall to be settled by a careful sifting of a mass of evidence which has already proved to be peculiarly rich in opportunities for mistake. It may be expected that the facts of infective parasitism and the facts of acquired disease-autonomy will in the end find their place in a common theory of specific diseases, which might be expressed in terms of the physiological formula morbus est vita praeter naturam with the rider morbus est vivum in vivo.

The theory of remedies, which forms the second division of the science of medicine, is chiefly based upon pharmacology or toxicology. If pharmacology be considered as not co-extensive with toxicology, it will be taken tobe in great part pharmacographia, or the systematic description of articles of the materia medica—their source, preparation, physical properties, and the like. Toxicology is in its general sense the investigation of the physiological action of drugs, a science which is largely dependent upon experiments on the lower animals; in a more technical sense toxicology relates to the effects of poisons and the art of detecting them (see Poisons). The physiological action of drugs is the key to their therapeutical action. Therapeutics has been defined as “the discovery of the means by which a system of forces competent to eliminate any given perturbation may be introduced into the economy.” The adaptation of remedies to diseases is, however, greatly wanting in precision, and continues to be in large part empirical and traditional. It may be objected to the above definition that all diseases are not reducible to the category of “perturbations,” and that there is a certain scientific justification for the doctrine of specifics. Besides the articles of the materia medica proper, agencies such as electricity, baths, sea-voyages, and changes of climate generally, enter into the consideration of therapeutics, and two of those form the subject of special departments, viz., electro-therapeutics and hydropathy. Regimen and diet are also important factors in the treatment of disease; according to a contention of Hippocrates, it was in the dietetic needs of mankind that the medical art had its origin.

Subdivisions of Medicine as an Ai t and, Discipline.— The medical art (ars medendi) breaks away at once from the unity of the theory of disease. While there is but one body of pathological doctrine for either sex, for every period of life, and for every region and part of the organism, the practical art divides itself into departments and subdepartments. The most fundamental division is into internal and external medicine, or into medicine proper and surgery. The treatment of wounds, injuries, and deformities, with operative interference in general, is the special department of surgical practice (the corresponding parts of pathology, including inflammation, repair, and removable tumours, are sometimes grouped together as surgical pathology); and where the work of the profession is highly subdivided, surgery becomes the exclusive province of the surgeon, while internal medicine remains to the physician. A third great department of practice is formed by obstetric medicine or midwifery, and with obstetrics there is usually associated gynaecology, or the diseases peculiar to women. Diseases of children are the subject of a voluminous separate literature. Dermatology (diseases of the skin) is an important province of practice which, like the diseases of women and children, pertains as much to medicine as to surgery. The greatest of the so-called special departments of practice is ophthalmology (diseases and injuries of the eye). Laryngology is a department that owes its existence mainly to the invention of the laryngoscope, its special province being the treatment of the inflammations (ordinary and specific), tumours, and the like, to which the larynx is liable in common with other parts. Diseases of the ear (otology) form even a more restricted department of practice, owing to the comparative inaccessibility of the chief part of the organ of hearing. The congenital condition of deaf-mutism may or may not be taken as falling within the province of the last-mentioned subdivision. Dentistry or odontology is extremely limited in the range of its subject-matter; but it affords great opportunities for refinements of technical skill, and it is given up to a distinct branch of the profession.

The care of the weak-minded and the insane (psychological medicine) is an integral part of medical practice, inasmuch as it is concerned with diseases of the nervous system and with numerous correlated states of other organs; but it occupies a unique place by reason of the engrossing interest of the subjective phenomena. Habitual drunkenness is also a subject of special treatment.

' A state of war, actual or contingent, gives occasion to special developments of medical and surgical practice (military hygiene and military surgery). Wounds caused by projectiles, sabres, &c., are the special subject of naval and military surgery; while under the head of military hygiene we may include the general subject of ambulances, the sanitary arrangements of camps, and the various forms of epidemic camp sickness.

The administration of the civil and criminal law involves frequent relations with medicine, and the professional subjects most likely to arise in that connexion, together with a summary of causes célèbret, are formed into the department of medical jurisprudence. It is the practice in Great Britain to call independent medical evidence on both sides of a cause, whether the proceedings be civil or criminal.

The system of life assurance is based upon the co-operation of the medical profession. Heredity, constitution, and diathesis are here the chief subjects of general consideration, while prognosis is the skilled faculty specially called into play.

Relations of Medicine to the Body Politic.— The statutes of the United Kingdom which have direct relation to medicine are (1) those relating to the public health; (2) those relating to lunacy (and habitual drunkenness); (3) those relating to the status of the medical profession, to dentists, and to pharmaceutical chemists; (4) those relating to restrictions on the “practice” of anatomy and physiology. There are, besides, several statutes in which medicine is concerned indirectly,—such as the Poor Laws, the Prisons Acts, the Shipping Acts, the Registration of Births and Deaths Act, the Sale of Food and Drugs Act, the Sale of Poisons Act, the Factory and Workshops Act, the Artisans’ Dwellings (Metropolitan) Act, the Rivers Pollution Prevention Act, the Contagious Diseases (Animals) Act (1878), and the Public Health...