1641 in science
# 1641 in science

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

## Medicine

* 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)
* September 26 – Nehemiah Grew, English botanist and physician who made some of the early microscopical observations of plants (died 1712)

## 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)
* Guy de La Brosse, French physician and botanist (born c. 1586)
