1641 in science

• Nicolaes Tulp's Observationes Medicae is published in Amsterdam. ==Technology==

• The sealed thermometer is developed with Ferdinand II, Grand Duke of Tuscany, using a glass tube containing alcohol, which freezes well below the freezing point of water. • Samuel Winslow is granted the first patent in North America by the Massachusetts General Court for a new saltmaking process. ==Births==

• March – Menno van Coehoorn, Dutch military engineer (died 1704) • July 30 – Regnier de Graaf, Dutch physician and anatomist who discovered the ovarian follicles, which were later named Graafian follicles (died 1673) • August 2 – Jacob Bobart the Younger, English botanist (died 1719) • September 26 – Nehemiah Grew, English botanist and physician who makes some of the early microscopical observations of plants (died 1712) • October 28 – Sir Philip Skippon, English traveller, naturalist and Member of Parliament (died 1691) ==Deaths==

• January 3 – Jeremiah Horrocks, English astronomer (born 1618) • March 8 – Xu Xiake, Chinese explorer and geographer (born 1587) • July 5 – Simon Baskerville, English physician (born 1574) • August 31 – Guy de La Brosse, French physician and botanist (born c. 1586) ==References==