ing Italy in 1641,
he remained during the winter of that year in Florence, studying the
"paradoxes of the great star-gazer" Galileo, who died within a league of
the city early in 1642. Returning to England in 1644 he found that his
father was dead and had left him the manor of Stalbridge in Dorsetshire,
together with estates in Ireland. From that time he gave up his life to
study and scientific research, and soon took a prominent place in the
band of inquirers, known as the "Invisible College," who devoted
themselves to the cultivation of the "new philosophy." They met
frequently in London, often at Gresham College; some of the members also
had meetings at Oxford, and in that city Boyle went to reside in 1654.
Reading in 1657 of Otto von Guericke's air-pump, he set himself with the
assistance of Robert Hooke to devise improvements in its construction,
and with the result, the "machina Boyleana" or "Pneumatical Engine,"
finished in 1659, he began a series of experiments on the properties of
air. An account of the work he did with this instrument was published in
1660 under the title _New Experiments Physico-Mechanical touching the
spring of air and its effects_. Among the critics of the views put
forward in this book was a Jesuit, Franciscus Linus (1595-1675), and it
was while answering his objections that Boyle enunciated the law that
the volume of a gas varies inversely as the pressure, which among
English-speaking peoples is usually called after his name, though on the
continent of Europe it is attributed to E. Mariotte, who did not publish
it till 1676. In 1663 the "Invisible College" became the "Royal Society
of London for improving natural knowledge," and the charter of
incorporation granted by Charles II. named Boyle a member of the
council. In 1680 he was elected president of the society, but declined
the honour from a scruple about oaths. In 1668 he left Oxford for London
where he resided at the house of his sister, Lady Ranelagh, in Pall
Mall. About 1689 his health, never very strong, began to fail seriously
and he gradually withdrew from his public engagements, ceasing his
communications to the Royal Society, and advertising his desire to be
excused from receiving guests, "unless upon occasions very
extraordinary," on Tuesday and Friday forenoon, and Wednesday and
Saturday afternoon. In the leisure thus gained he wished to "recruit his
spirits, range his papers," and prepare some important chemical
investigatio