(Lewis Otto), in Latin Menkenius, a learned professor of morality at Leipzig, was born at Oldenburg in Westphalia in 1644. He studied in several universities of Germany; and became an able philosopher, civilian, and divine. He was made professor of morality at Leipzig in 1668; and enjoyed that post to his death. He was five times rector of the university of that city, and seven times dean of the faculty of philosophy. He published several works; but his most considerable, and what alone is sufficient to perpetuate his memory, is the Ada Eruditorum of Leipzig, of which he was the first author, and in which he was engaged till his death. The first volume was published at Leipzig, in 4to, in 1682.

Mencke (John Burchard), son to the preceding. After his studies he travelled into England and Holland; and upon his return was appointed professor of history at Leipzig in 1699. He gained great reputation by his lectures as well as his writings. He died in 1732, aged 58. He wrote many pieces. His De Charlataneria eruditorum declamationes due, is an excellent satire, designed to expose the artifices used by false scholars to raise themselves a name. As he named and pointed at certain persons, it exasperated them, and they procured his book to be seized; but it spread, and editions of it were multiplied. He likewise published Methode pour étudier l'Histoire, avec un catalogue des principaux historiens, &c. He made a great many additions to Mr Lenglet's book, especially with regard to the German historians.