His time was wholly taken up in visiting the sick, studying, making chemical experiments, searching into every part of medicine with the utmost diligence, teaching the mathematicks, and reading the scriptures, and those authors who profess to teach a certain method of loving God.*

This was his method of living to the year 1701, when he was recommended by Van Berg to the university, as a proper person to succeed Drelincurtius in the professorship of physick, and elected without any solicitations on his part, and almost without his consent, on the 18th of May.

On this occasion, having observed, with grief, that Hippocrates, whom he regarded not only as the father but as the prince of physicians, was not sufficiently read or esteemed by young students, he pronounced an oration, "de commendando Studio "Hippocratico;" by which he restored that great author to his just and ancient reputation.

He now began to read publick lectures with great applause, and was prevailed upon by his audience to enlarge his original design, and instruct them in chemistry.

*Circa hoc tempus, lautis conditionibus, lautioribus promissis, invitatus, plus vice simplici, a viro primariæ dignationis, qui gratia flagrantissima florebat regis Gulielmi III. ut Hagamcomitum sedem caperet fortunarum, declinavit constans. Contentus videlicet vita libera, remota a turbis, studiisque porro percolendis unice impensa, ubi non cogeretur alia dicere et simulare, alia sentire et dissimulare: affectuum studiis rapi, regi. Sic tum vita erat, ægros visere, mox domi in museo se condere, officinam Vulcaniam exercere; omnes medicinæ partes acerrime persequi; mathematica etiam aliis tradere; sacra legere, et auctores qui profitentur docere rationem certam amandi Deum." Orig, Edit.

This he undertook, not only to the great advan tage of his pupils, but to the great improvement of the art itself, which had hitherto been treated only in a confused and irregular manner, and was little more than a history of particular experiments, not reduced to certain principles, nor connected one with another: this vast chaos he reduced to order, and made that clear and easy, which was before to the last degree difficult and obscure.

His reputation now began to bear some proportion to his merit, and extended itself to distant universities; so that, in 170S, the professorship of physick being vacant at Groningen, he was invited thither; but he refused to leave Leyden, and chose to continue his present course of life.

This invitation and refusal being related to the governors of the university of Leyden, they had so grateful a sense of his regard for them, that they. immediately voted an honorary increase of his salary, and promised him the first professorship that should be vacant.

On this occasion he pronounced an oration upon the use of mechanicks in the science of physick, in which he endeavoured to recommend a rational and mathematical enquiry into the causes of diseases, and the structure of bodies; and to shew the follies and weaknesses of the jargon introduced by Paracelsus, Helmont, and other chemical enthusiasts, who have obtruded upon the world the most airy dreams, and instead of enlightening their readers with explications of nature, have darkened the plainest appearances, and bewildered mankind in error and obscurity.

Boerhaave had now for nine years read physical lectures, but without the title or dignity of a professor, when, by the death of professor Hotten, the professorship of physick and botany fell to him of

course.

On this occasion he asserted the simplicity and facility of the science of physick, in opposition to those that think obscurity contributes to the dignity of learning, and that to be admired it is necessary not to be understood.

His profession of botany made it part of his duty to superintend the physical garden, which improved so much by the immense number of new plants which he procured, that it was enlarged to twice its original extent.

In 1714, he was deservedly advanced to the highest dignities of the university, and in the same year made physician of St. Augustin's hospital in Leyden, into which the students are admitted twice a week, to learn the practice of physick.

This was of equal advantage to the sick and to the students, for the success of his practice was the best demonstration of the soundness of his principles.

When he laid down his office of governor of the university in 1715, he made an oration upon the subject of "attaining to certainty in natural philosophy;" in which he declares, in the strongest terms, in favour of experimental knowledge, and reflects, with just severity, upon those arrogant philosophers, who are too easily disgusted with the slow methods of obtaining true notions by frequent experiments, and who, possessed with too high an

opinion of their own abilities, rather chuse to consult their own imaginations, than enquire into nature, and are better pleased with the charming amusement of forming hypotheses, than the toilsome drudgery of making observations.

The emptiness and uncertainty of all those systems, whether venerable for their antiquity, or agreeable for their novelty, he has evidently shewn; and not only declared, but proved, that we are entirely ignorant of the principles of things, and that all the knowledge we have is of such qualities alone as are discoverable by experience, or such as may be deduced from them by mathematical demonstration.

This discourse, filled as it was with piety, and a true sense of the greatness of the Supreme Being, and the incomprehensibility of his works, gave such offence to a professor of Franeker, who professed the utmost esteem for Des Cartes, and considered his principles as the bulwark of orthodoxy, that he appeared in vindication of his darling author, and spoke of the injury done him with the utmost vehemence, declaring little less than that the Cartesian system and the Christian must inevitably stand and fall together, and that to say that we were ignorant of the principles of things, was not only to enlist among the Sceptics, but sink into Atheism itself.

So far can prejudice darken the understanding, as to make it consider precarious systems as the chief support of sacred and invariable truth...

This treatment of Boerhaave was so far resented by the governors of his university, that they procured from Franeker a recantation of the invective that had been thrown out against him; this was not

only complied with, but offers were made him of more ample satisfaction; to which he returned an answer not less to his honour than the victory he gained, “that he should think himself sufficiently compensated, if his adversary received no farther "molestation on his account."

So far was this weak and injudicious attack from shaking a reputation not casually raised by fashion or caprice, but founded upon solid merit, that the same year his correspondence was desired upon Botany and Natural Philosophy by the Academy of Sciences at Paris, of which he was, upon the death of Count Marsigli, in the year 1728, elected a

member.:

Nor were the French the only nation by which this great man was courted and distinguished; for, two years after, he was elected fellow of our Royal Society.

It cannot be doubted but, thus caressed and honoured with the highest and most publick marks of esteem by other nations, he became more celebrated in the university; for Boerhaave was not one of those learned men, of whom the world has seen too many, that disgrace their studies by their vices, and by unaccountable weaknesses make themselves ridiculous at home, while their writings procure them the veneration of distant countries, where their learning is known, but not their follies.

Not that his countrymen can be charged with being insensible of his excellences till other nations taught them to admire him; for in 1718 he was chosen to succeed Le Mort in the professorship of chemistry; on which occasion he pronounced an ora