1667 in science

The year 1667 in science and technology involved some significant events.

• June 24 – The site of the Paris Observatory is located on the Paris Meridian.

• Johann Joachim Becher originates what will become known as phlogiston theory in his Physical Education.^[1]

• Thomas Sprat publishes The History of the Royal-Society of London, for the Improving of Natural Knowledge.

• James Gregory demonstrates the transcendence of π.^[2]

• June 15 – Jean-Baptiste Denys performs the first blood transfusion from a lamb into a boy.
• Robert Hooke demonstrates that the alteration of the blood in the lungs is essential for respiration.
• Thomas Willis publishes Pathologicae Cerebri, et nervosi generis specimen.

• Nicolas Steno publishes Elementorum Myologiae Specimen, seu Musculi Descriptio Geometrica. Cui accedunt canis carchariae dissectum caput, et dissectus piscis ex canum genere in Florence, providing a foundation for the study of muscle mechanics, the ovary (based on his dissection of dogfish), and the sedimentary theory of geology.^[3]

• April 29 (bapt.) – John Arbuthnot, Scottish-born polymath (died 1735)
• May 2 – Jacob Christoph Le Blon, German inventor of four-colour printing (died 1741)
• May 26 – Abraham de Moivre, French mathematician (died 1754)
• July 27 – Johann Bernoulli, Swiss mathematician (died 1748)

• April 3 – Edward Somerset, 2nd Marquess of Worcester, English inventor (born 1601?)
• April 10 – Jan Marek Marci, Bohemian physician (born 1595)
• June 5 – Grégoire de Saint-Vincent, Flemish mathematician (born 1584)
• probable date – Peter Mundy, English traveller (born c. 1596)