MERSENNE, MARIN, in Latin Mersennus, a learned
French author, born at Oylé, in the province of
Maine, anno 1588. He studied at La Flicke at the
same time with Des Cartes; with whom he contracted
a strict friendship, which lasted till death. He af-
terwards went to Paris, and studied at the Sorbonne; and
in 1611 entered himself among the Minims. He became
well skilled in Hebrew, philosophy, and mathematics.
He was of a tranquil, sincere, and engaging temper;
and was universally esteemed by persons illustrious for
their birth, their dignity, and their learning. He
taught philosophy and divinity in the convent of Nevers,
and at length became superior of the convent; but
being willing to apply himself to study with more free-
dom, he resigned all the posts he enjoyed in his order,
and travelled into Germany, Italy, and the Netherlands.
He wrote a great number of excellent works; the prin-
cipal of which are, 1. Questiones celeberrime in Genesim.
2. Harmonicum libri. 3. De sonorum natura, causis,
et effectibus. 4. Cogitata physico-mathematica. 5. La
verité des Sciences. 6. Les questions inouies. He died
at Paris in 1648. He had the reputation of being one
of the best men of his age. No person was more curious
in penetrating into the secrets of nature, and carrying
all the arts and sciences to their utmost perfection. He
was in a manner the centre of all the men of learning,
by the mutual correspondence which he managed
between them. He omitted no means to engage them
to publish their works; and the world is obliged to
him for several excellent discoveries, which, had it not
been for him, would perhaps have been lost.