Hermann Boekhaaye, a Dutch physician, born at Voorhout, near Leyden, Dec. 31, 1668, died in Leyden, Sept. 23, 1738. His father was a clergyman, and he was destined for the same calling. He studied at Leyden under Gronovius, Ryckius, and Trigland, and obtained the highest academical honors. In 1689 he received his degree in philosophy, the subject of his thesis being the distinction between mind and matter, in which he condemned the doctrines of Epicurus, Hobbes, and Spinoza, and maintained that the doctrines of Epicurus had been completely analyzed and refuted by Cicero. For this dissertation a gold medal was given to him by the city. After the death of his father Boerhaave supported himself for a while by teaching mathematics, and then engaged in the study of medicine. In 1693 he obtained his degree of doctor of medicine at Harderwyck, and immediately entered on the duties of his profession. 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 wasentirled De commendando Hippocra-tis Studio, in which he recommended to his pupils the study of the works of that writer as the best source of instruction.

He was fond of chemistry, botany, and mathematics, and these sciences were much consulted in his medical investigations. In 1708 he published at Leyden the Institutiones Medicae in Usus Annum Exercitationis Domesticos, a comprehensive work on the study and practice of medicine, the functions of the body, health, disease, and the means of prolonging life. The next year appeared his Aphorismi de Cognoscendis et Curandis Morbis, a classification of diseases, with explanations of their causes, symptoms, and treatment. These two works, which show immense learning and are models of style, passed through numerous editions, were copiously annotated, and translated into many languages. In 1709 he was appointed successor to Hotton in the chair of botany and medicine. Under his influence additions were made to the botanical garden of Leyden, and he published numerous works descriptive of new species of plants. In 1714 he was appointed rector of the university, and in the same year succeeded Bidloo in the chair of practical medicine. In this position he had the merit of reviving the ancient system of clinical instruction.

In 1718 he was appointed to the chair of chemistry, and the fruit of his labors in this position appeared some years later in his Elementa Chemice (best ed., 4to, Leyden, 1732). In 1729 declining health induced him to resign the chairs of chemistry and botany, and in 1731 he resigned the rectorship of the university, delivering a discourse De Honore Medici Servitute. Besides attending to his active duties as rector of the university and professor of chemistry, botany, and medicine, Boerhaave was always much consulted as a practical physician. He was simple and economical in his habits, and when he died he left a fortune of 2,000,000 florins to his only surviving daughter. - The genius of Boerhaave attracted students to the university of Leyden from all parts of Europe; and when Peter the Great revisited Holland in 1716, he had recourse to him for instruction. From the time of Hippocrates, no physician had excited so much admiration as Boerhaave. His personal appearance was simple and venerable; to uncommon intellectual powers he united gentleness, benevolence, and amiable manners. In lecturing, his style was eloquent and graceful, his ideas clear, and his delivery perfect. He possessed an excellent memory, and was an accomplished linguist and fond of music.

He was of a religious turn of mind, and usually devoted an hour early in the morning to reading the Scriptures and pious meditations, to which habit he attributed his faculty of enduring with cheerfulness his immense labors. The city of Leyden raised a monument to his memory in the church of St. Peter, inscribed "To the health-giving skill of Boerhaave" (Salutifero Boerhaarii genio sacrum), and on which was engraved his motto, Simplex rigittum veri.