such that at the end of his course his delighted pupils prevailed upon him to instruct them in chemistry likewise.
Two years later he was invited to a vacant professorship at Groningen, which he declined with grateful acknowledgments. Thereupon his trusty friend Van der Berg, President of the Burgomasters and one of the seven curators of the university, induced the authorities to increase his salary, and to promise to him the first vacancy in the regular professorships. This did not occur until 1709, when, on the death of Dr. Hotton, he was made Professor of Medicine and of Botany.
By the aid of returning captains, at a time when Dutch ships ruled the sea, and by a system of exchanges with noted correspondents, in ten years he had doubled the number of plants in the botanical garden. Crocodiles, turtles, and other strange creatures were imported from distant settlements in the Indies. The bamboo, the papyrus, the palm, the coffee plant, trees of cinnamon, camphor, and mahogany could be seen growing in the open air and in hothouses. The plants were especially remarkable for their strength and vigor. In their classification Boerhaave prepared the way for Linnaeus.
In 1714 Boerhaave was elected to the rectorship of the university—"of their Noble High Mightenesses' University of Leyden," he terms it in his correspondence—and in the same year was appointed Professor of Physic in place of Prof. Bidloo, and to a position in the University Hospital. By this time his fame had outgrown its local limits, and students flocked to him from all parts of the world. When he began his public teachings, the doctrines of Van Helmont and Paracelsus were held in high favor. Indeed, he tells us that the works of the former he read through seven times and those of the latter four times. Van Helmont he regarded rather as a philosopher than as a physician, as his boasted remedies fell far short of their promised efficiency. Yet Paracelsus swore by his own soul, and calls every god in heaven to witness, that with one single remedy he was able to cure all diseases, be they what they would; and in another place he declares that no one need scruple about getting certain secrets of physic from the devil, and boasts of holding conversations with Galen and Avicenna at the gates of hell. By the school of Paracelsus it was claimed that the doctrine of transmutation was contained in the Pentateuch, in the books of Solomon, and in the Revelation of St. John.
Van Helmont's methods are illustrated by an account he gives us of how he treated himself for pneumonia. In 1640, in the sixtythird year of his age, he was seized with a fever, attended with a slight shivering which made his teeth chatter; a pricking pain about the sternum, a difficulty of respiration, and a spitting first
