# Hospital, William-Francis-Antony, Marquis De L'

, a great mathematician of France, was born of a branch
of the preceding family, in 1661. He was a geometrician
almost from his infancy; for one day being at the duke de
Rohan’s, where some able mathematicians were speaking
of a problem of PaschaPs, which appeared to them extremely difficult, he ventured to say, that he, believed he
could solve it. They were amazed at what appeared such
unpardonable presumption in a boy of fifteen, for he was
then no more, yet it a few days be sent them the solution.
He entered early into the army, but always preserved his
love for the mathematics, and studied them even in his
tent; whither he used to retire, it is said, not only to
study, but also to conceal his application to study: for in
| those days, to be knowing in the sciences was thought to
derogate from nobility; and a soldier of quality, to preserve his dignity, was in some measure obliged to hide his
literary attainments. De l’Hospital was a captain of horse;
but, being extremely short-sighted, and exposed on that
account to perpetual inconveniences and errors, he at
length quitted the army, and applied himself entirely
to his favourite amusement. He contracted a friendship with Malbranche, judging by his “Recherche de la
Verite*,” that he must be an excellent guide in the sciences;
and he took his opinion upon all occasions. His abilities
and knowledge were no longer a secret: and at the age of
thirty-two he gave a public solution of problems, drawn
from the deepest geometry, which had been proposed to
mathematicians in the acts of Leipsic. In 1693 he was received an honorary member of the academy of sciences at
Paris; and published a work upon sir Isaac Newton’s calculations, entitled “L’Analyse des iniinimens petits.” He
was the first in France who wrote on this subject: and on
this account was regarded almost as a prodigy. He engaged afterwards in another work of the mathematical kind,
in which he included “Les Sectiones coniques, les Lieux
georoetriques, la Construction des Equations,” and “Une
Theorie des Courbes mechaniques:” but a little before he
had finished it, he was seized with a fever, of which he
died Feb. 2, 1704, aged 49. It was published after his
death, viz. in 1707. There are also six of his pieces inserted in different volumes of the memoirs of the academy
of sciences. ^{1}