- May 3 – Total solar eclipse across southern England, Sweden and Finland (last total eclipse visible in London for almost 900 years).
- Edmond Halley suggests that nebulae are clouds of interstellar gas.
- Publication in London of David Gregory's The elements of astronomy, physical and geometrical... Done into English, containing the first recorded use in English of the word Physics in its modern scientific sense and the first mention of a series approximating the Titius–Bode law on celestial orbits.
- French anatomist Raymond Vieussens's Traité nouveau de la structure et des causes du mouvement naturel du coeur is published in Toulouse, giving the first description of valvular disease of the heart.
- January 29 – Bernard Lamy, French mathematician, philosopher and physicist (born 1640)
- February 17 – Antoine Galland, French archaeologist (born 1646)
- March – William Dampier, English explorer, hydrographic surveyor and triple circumnavigator (born 1651)
- May – Thomas Savery, English engineer, inventor of a steam pump (born c. 1650)
- May 21 – Pierre Magnol, French botanist (born 1638)
- June 19 – Nicolas Lémery, French pharmacist and chemist (born 1645)
- August 16 – Raymond Vieussens, French anatomist (born c. 1635)
- September 24 – Wilhelm Homberg, Dutch chemist working in France (born 1652)
- October 15 – Humphry Ditton, English mathematician (born 1675)
- November 1 – Shibukawa Shunkai, Japanese scholar and astronomer (born 1637)