Herman, the most celebrated physician of the eighteenth century, and one who without impropriety may be opposed to the Galen of antiquity, if not in extent of genius, at least for the number and variety of his acquirements, the exclusive empire which his medical system obtained, and the immense celebrity which he enjoyed during his life. He was born in 1668, at Worhout, a village near Leyden. At the age of sixteen he found himself without parents, protection, advice, or fortune. He had already studied theology and the other ecclesiastical sciences, with the view of devoting himself to a clerical life; but the science of nature, which had equally occupied his mind, soon engrossed his whole attention. This illustrious person, whose name afterwards spread throughout the world, and who left at his death above L200,000, could at that time barely live by his labours, and was compelled to teach mathematics in order to obtain the means of subsistence. But in 1693 he was received as doctor of physic, and began practice; and his merit having been discovered, many powerful friends patronized him, and procured him three valuable appointments; first, that of professor of medicine in the university of Leyden; secondly, that of professor of chemistry; and thirdly, that of professor of botany. The Academy of Sciences of Paris, and the Royal Society of London, each invited him to become one of their members; and he communicated to both his discoveries in chemistry. In Boerhaave's time the city of Leyden became the school of Europe for this science, as well as for medicine and botany. All the princes of Europe sent him disciples, who found in this skilful professor not only an indefatigable teacher, but an affectionate guardian, who encouraged them to pursue their labours, consoled them in their afflictions, and solaced them in their wants. When Peter the Great went to Holland in 1715, to instruct himself in maritime affairs, he also attended Boerhaave in order to receive lessons. The reputation of the latter extended as far as China: a mandarin wrote to him a letter superscribed with this direction, "To the illustrious Boerhaave, physician in Europe;" and it reached him in due course. The city of Leyden has raised a monument in the church of St Peter, to the salutary genius of Boerhaave, Salutifero Boerhaavii genio sacrum.

From the time of Hippocrates, no physician had more justly merited the esteem of his contemporaries, and the thanks of posterity, than Boerhaave. To an uncommon genius and extraordinary talents he united those qualities of the heart which give them so great a value to society. His appearance was decent, simple, venerable, and, latterly, almost patriarchal. He was an eloquent orator, and discoursed with dignity and grace. He taught very methodically, and with great precision; he never tired his auditors, who always regretted when his discourses were finished. He would sometimes also give them a lively turn; but his merriment was refined and ingenious, and it enlivened the subject he treated of, without carrying with it any thing severe or satirical. A declared foe to all excess, he considered decent mirth as the salt of life. It was the daily practice of this eminent person, throughout his life, as soon as he rose in the morning, which was generally very early, to retire for an hour to private prayer, and meditation on some part of the Scriptures. He often told his friends, when they asked him how it was possible for him to go through so much fatigue, that it was this practice which gave him spirit and vigour in the business of the day. He therefore recommended it as the best rule he could give; for nothing, said he, can tend more to the health of the body than the tranquillity of the mind.

Of his sagacity, and the wonderful penetration with which he often discovered and described, at first sight, such distempers as betray themselves by no symptoms to common eyes, very surprising accounts have been transmitted to us. Yet this great master of medical knowledge was so far from having presumptuous confidence in his own abilities, or from being puffed up by riches, that he was condescending to all, and remarkably diligent in his profession; and he used often to observe that the life of a patient, if trifled with or neglected, would one day be required at the hand of the physician. The activity of his mind sparkled visibly in his eyes. He was always cheerful, and desirous of promoting every valuable end of conversation, of which the excellency of the Christian religion was frequently the subject; for he asserted, on all proper occasions, the divine authority and sacred efficacy of the Scriptures. He never regarded calumny nor detraction,—for even Boerhaave himself had enemies,—nor in any instance thought it necessary to confute them. "They are sparks," said he, "which, if you do not blow them, will go out of themselves. The surest remedy against scandal, is to live it down by a perseverance in well-doing; and by praying to God that he would cure the distempered minds of those who traduce and injure us." Being once asked by a friend, who had often admired his patience under great provocations, whether he knew what it was to be angry, and by what means he had so entirely suppressed that impetuous and ungovernable passion, he answered, with the utmost frankness and sincerity, that he was naturally quick of resentment; but that, by daily prayer and meditation, he had at length attained to this mastery over himself.

About the middle of the year 1737 he felt the first approaches of that fatal illness which brought him to the grave; namely, a disorder in the chest, which was at times very painful, often threatening him with immediate suffocation, and which terminated in an universal dropsy. But during this afflictive and lingering illness, his constancy and firmness did not forsake him; he neither intermitted the necessary cares of life, nor forgot the proper preparations for death. About three weeks before his dissolution, when the Rev. Mr Schultens, one of the most learned and exemplary divines of the age, attended him at his country-house, the doctor desired his prayers, and afterwards entered into a most remarkably judicious discourse with him on the spiritual and immaterial nature of the soul; and this he illustrated to Mr Schultens with wonderful perspicuity, by a description of the effects which the infirmities of his body had upon his faculties; which, however, they did not so oppress or vanquish as to deprive his mind of the mastery over itself. As death approached nearer, he was so far from terror or confusion, that he seemed less sensible of pain, and more cheerful under his sufferings, which continued till the 23d day of September 1738, when he died, between four and five in the morning, in the seventieth year of his age; often recommending to the bystanders a careful observation of St John's precepts concerning the love of God and the love of man, as frequently inculcated in his first epistle, particularly in the fifth chapter. His funeral oration was spoken in Latin before the university of Leyden, to a very numerous audience, by Mr Schultens, and afterwards published at their particular desire.

When Boerhaave first directed his attention to medicine, the new philosophy of Bacon, and the creation of the experimental art, had caused the physical sciences to make great advancement; and these, accordingly, occupied all minds, whilst the healing art had but little profited in consequence. It was overlooked or forgotten, that, from its very origin, Hippocrates had applied to it the very philosophy with which the learned were now everywhere so enthusiastically occupied. His theory, however, still continued to fluctuate between several dogmas equally remote from the truth. The chemists who, at the revival of learning in Europe, had overturned the authority of Galen, had to defend themselves against the sects of the mechanicians, and of Bellini, which divided the domain of medicine between them. In a small portion of Germany alone Stahl brought back men's minds to the judicious doctrine of Hippocrates, attributing all the movements in the animal economy to a force inherent in itself, and different from the general forces of matter; but in adopting a word, the meaning of which was by no means precise, he rendered less general and less salutary the influence which he would otherwise have produced. The first perusal of Hippocrates appeared to have carried away Boerhaave; but this physician, endowed by nature with a mind fitted for analysis, comparison, and combination, rather than with a creative and inventive genius, was unable to resist the influence of his age, and, above all, the effect of his early studies. Having been a mathematician and natural philosopher before he became physician, he was constantly carried away by the first objects of his labour and research; and being more capable than any one else of detecting the accessory affinities between these sciences and that of man, he ran greater risk of being seduced by them. But as every system, however vicious, has always, along with the facts which it arranges and offers to explain, a point of accordance more or less remote, he thought that the best medical system would be that which should unite and combine all opinions. Forgetting that living bodies are free, during their life, from those movements to which other bodies are imperiously constrained, or at least counterbalance them, and that all the acts which they perform are the result of an activity which is peculiar to them; overlooking, also, that those of the movements of the living economy which most easily admit an application of the laws of physics and mechanics, have, nevertheless, as a primum mobile, the force of life, and only receive from the forces of dead matter an accessory impulse; Boerhaave wished to combine in one and the same theory the vital philosophy of Hippocrates, the chemical principles of Sylvius, the mechanism of Bellini, and many other incongruities besides; attributing more, however, to the mechanical and chemical forces, which can never be but accessory, than to the more profound and secret powers of life, which are the principal. Thus the calibre of the vessels adjusted to the dimensions of the globules composing the liquids of the body, formed, according to him, the hydraulic relation on which depended the circulation of the humours, their separation from the blood in the different secretory organs, the morbid congestion of the blood in various fluxions, in humours, inflammations, and such like; and hence he concluded that all the efforts of the physician should be directed to establish this relation, or rather mechanical equilibrium. Nor did he stop even here. To the mechanical hypotheses just mentioned he added others founded on chemical principles, when, in attempting to explain the causes and the phenomena of diseases, he admitted the formation of pretended acrimonies in the blood, which the physician ought, according to him, to have constantly in view in order to neutralize them; acrimonies which were long famous in the language of the schools, and which are still found in that of ordinary life. The whole phenomena of diseases, with the spontaneous evacuations by which they are terminated, and which constitute Boethius' crises, find a ready explanation on this vicious system, which seems to offer a reason, when it only mystifies with a word, involving a gratuitous hypothesis. In practice, however, theory receives many modifications; and there can be little doubt, that in prescribing for patients, Boerhaave was more guided by experience and good sense than by the strangely eclectic doctrine to which we have here cursorily alluded.

The principal works of this illustrious physician are:

1. *Institutiones Medicae*, Leyden, 1708; 2. *Aphorismi de cognoscendis et curandis Morbis*, Leyden, 1709; 3. *Institutiones et Experimenta Chymiae*, Paris, 1724; 4. *Libellus de Materia Medica, et Remediiorum Formulis quae serviant Aphorismus*. Van Swieten published *Commentaries upon his Aphorisms*, in five vols. 4to; and several other works, all greatly esteemed.