- Niels Steensen
- Nicolaus Steno
- Father of Geology
Anatomist and priest. Among his anatomical achievements was the discovery of the excretory duct of the parotid glands and the circulation of the blood in the body. When the Danes finally called for him to return, he had become a Catholic in Florence, Italy, and as such could not return. In Italy he made many geological discoveries and was the first to explain petrifactions in the earth. Ordained in 1675, he was made vicar Apostolic for the northern missions and titular bishop of Titiopolis. He was in a constant personal struggle to have this faith and his scientific discoveries exist and work together.
- “Blessed Niels Stenson“. CatholicSaints.Info. 10 December 2016. Web. 27 February 2017. <>