1641 in science

The year 1641 in science and technology involved some significant events.

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

• 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.^[1]

• 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)

• 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)