1691 in science

Biology

• Italian Jesuit scholar Filippo Bonanni publishes the results of his microscopic observations of invertebrates in Observationes circa Viventia, quae in Rebus non-Viventibus.

Mathematics

• Gottfried Leibniz discovers the technique of separation of variables for ordinary differential equations.
• Michel Rolle invents Rolle's theorem.

Medicine

• Anton Nuck's Adenographia curiosa et uteri foeminei anatome nova is published at Leiden, including a description of the canal of Nuck and a demonstration that the embryo is derived from the ovary and not the sperm.

Technology

• Edmond Halley devises a diving bell.
• In music, the "equal temperament scale" used in modern music is developed by organist Andreas Werckmeister.

Births

• November 18 – Mårten Triewald, Swedish mechanical engineer (died 1747)

Deaths

• January 17 – Richard Lower, English physician who performed the first direct blood transfusion (born 1631)
• December 31 – Robert Boyle, Anglo-Irish chemist (born 1627)

References

References

1. Enersen, Ole Daniel. "Nuck's canal". [[Who Named It?.
2. Speert, Harold. (1958). "Obstetric and Gynecologic Milestones". Macmillan.
3. "History of diving". [[South Pacific Underwater Medicine Society]] Journal.
4. "Robert Boyle {{!}} Biography, Contributions, Works, & Facts".