HERMANN BOERHAAVE, one of the most celebrated physicians of modern times, was born at Voorhout near Leyden, December 31, 1668. Destined for the clerical profession, to which his father belonged, he received a liberal education, and early displayed unusual abilities. At the age of sixteen he entered the University of Leyden, where he studied under Gronovius, Ryckius, Trigland, and other distinguished men, and obtained the highest academical honours. In 1690 he took his degree in philosophy; on which occasion he delivered an inaugural dissertation De distinctions mentis a corpore, wherein he attacked the doctrines of Epicurus, Hobbes, and Spinoza. Being left, on the death of his father, without any provision, he was compelled to support himself by teaching mathematics. By the advice of Vandenberg, the burgomaster of Leyden, Boerhaave now applied himself with ardour to the study of medicine, to which indeed he had early manifested a decided inclination. The works of Hippocrates among the ancients, and those of Sydenham among the moderns, were the especial objects of his study; but his reading was by no means confined to these authors. In 1693 he took his degree of M.D. at Harderwyck in Guelderland, and immediately entered on the studies of his profession. His merits were soon recognized, and in 1701 he was appointed by the University of Leyden to supply the place of Drelincourt as lecturer on the institutes of medicine. His inaugural discourse on this occasion was entitled De commendando Ilippocratis studio, in which he recommended to his pupils that great physician as their model. In 1709, the university appointed him successor to Hotton in the chair of botany and medicine, in which capacity he did good service, not only to his own university, but also to botanical science, by his improvements and additions to the botanic garden of Leyden, and by the publication of numerous works descriptive of new species of plants. He was appointed in 1714 rector of the university. In the same year he succeeded Bidloo in the chair of practical medicine, and in this capacity he had the merit of introducing into modern practice the system of clinical instruction. Four years later he was appointed to the chair of chemistry, and delivered an inaugural discourse, which contains the germs of his celebrated Elements of Chemistry. In 172S he was elected into the Royal Academy of Sciences of Paris, and two years later into the Royal Society of London; to both of which he communicated his chemical researches In 1729 declining health obliged him to resign the chairs of chemistry and botany ; and in 1731 he resigned the rectorship of the university, to which office he had been re-elected On this occasion he delivered a discourse De Honore Medici Servitute. This great and good man died, after a lingering and painful illness, on th morning of the 23rd September 1738.

From the time of Hippocrates, no physician had more justly merited the esteem of his contemporaries n< i the admiration of posterity than Boerhaave. To uncommon intellectual abUities he united those amiable qualities of the heart which give them so great a value to society. His personal appearance was simple and venerable. He taught very methodically, and with great precision ; his style was eloquent, and his deUvery dignified and graceful. He sometimes also gave his lectures a lively turn; but his raillery was never coarse or satirical. He possessed remarkable powers of memory, and was an accomplished linguist. A declared foe to all excess, he considered decent mirth as the salt of life. He was fond of music, with which he had a scientific acquaintance ; and during winter he had a weekly concert in his house. It was his daily practice throughout Ufe, 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.

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 so far was he from having presumptuous confidence in his own abilities, or from being puffed up by prosperity, that he was condescending to all, and remarkably diligent in his profession. His great skill and celebrity as a physician brought him a large fortune. He left his only surviving daughter two millions of florins.

The genius of Boerhaave raised the fame of the University of Leyden, especially as a school of medicine, so as to make it a resort of strangers from every part of Europe. All the princes of Europe sent him disciples, who found in this skillful professor not only an indefatigable teacher, but an affectionate guardian. When Peter the Great went to Holland in 1715, to instruct himself in maritime affairs, he also took lessons from Boerhaave. The reputation of this eminent man was not confined to Europe; a Chinese mandarin wrote him a letter directed " To the illustrious Boerhaave, physician in Europe," and it reached him in due course. The city of Leyden raised a splendid monument to his memory in the church of St Peter, inscribed " To the health-giving genius of Boerhaave," SALUTIFERO
BOERHAAVII GENTO SACRUM.

The principal works of Boerhaave are—(1.) Institutiones Medicae, Leyden, 1708; (2.) Aphorismi de cognoscendis et curandis Morbis, Leyden, 1709,—on this work, which was the text-book of Boerhaave's iectures, Van Swieten published a commentary in 5 vols. 4to; (3.) Libellus de Materia Medica et Remediorum Formulis, Leyden, 1719; (4.) Institutiones et Expenmenta Chemioe, Paris, 1724.