"patientia Christiana," which Lipsius, the great master of
the stoical philosophy, begged of God in his last hours; it was
founded on religion, not vanity, not on vain reasonings, but on
confidence in God.

In 1727, he was seized with a violent burning fever, which continued
so long, that he was once more given up by his friends.

From this time he was frequently afflicted with returns of his
distemper, which yet did not so far subdue him, as to make him lay
aside his studies or his lectures, till, in 1726, he found himself so
worn out, that it was improper for him to continue any longer the
professorships of botany or chymistry, which he, therefore, resigned,
April 28, and, upon his resignation, spoke a "Sermo academicus," or
oration, in which he asserts the power and wisdom of the creator from
the wonderful fabrick of the human body; and confutes all those idle
reasoners, who pretend to explain the formation of parts, or the
animal operations, to which he proves, that art can produce nothing
equal, nor any thing parallel. One instance I shall mention, which is
produced by him, of the vanity of any attempt to rival the work of
God. Nothing is more boasted by the admirers of chymistry, than that
they can, by artificial heats and digestion, imitate the productions
of nature. "Let all these heroes of science meet together," says
Boerhaave; "let them take bread and wine, the food that forms the
blood of man, and, by assimilation, contributes to the growth of the
body: let them try all their arts, they shall not be able, from these
materials, to produce a single drop of blood. So much is the most
common act of nature beyond the utmost efforts of the most extended
science!"

From this time Boerhaave lived with less publick employment, indeed,
but not an idle or an useless life; for, besides his hours spent in
instructing his scholars, a great part of his time was taken up by
patients, which came, when the distemper would admit it, from all
parts of Europe to consult him, or by letters which, in more urgent
cases, were continually sent to inquire his opinion and ask his
advice.

Of his sagacity, and the wonderful penetration with which he often
discovered and described, at first sight of a patient, such distempers
as betray themselves by no symptoms to common eyes, such wonderful
relations have been spread over the world, as, though attested beyond
doubt, can scarcely be credited. I mention none of them, because I
have