PETER DE, a very distinguished natural philosopher and mathematician, was born Muschen-broek was born at Utrecht a little before 1700. He was first professor in his own university, and afterwards invited to the chair at Leyden, where he died full of reputation and honours in 1761. He was a member of several academies; particularly the Academy of Sciences at Paris. He was the author of several works in Latin, which are frequently referred to, and all of which discover great penetration and exactness of the subjects of which he treats. He was also consummate in the knowledge of law.