Rasmus Bartholin (Latinized Erasmus Bartholinus; 13 August 1625, Roskilde – 4 November 1698, Kopenhagen) was a Danish scientist and physician. As part of his studies, he travelled in Europe for ten years. Professor at the University of Copenhagen, first in Geometry, later in Medicine. He was a younger brother of Thomas Bartholin.

Rasmus Bartholin is remembered especially for his discovery (1669) of the double refraction of a light ray by Iceland spar (calcite). He published an accurate description of the phenomenon, but since the physical nature of light was poorly understood at the time, he was unable to explain it. It was only after Thomas Young proposed the wave theory of light, c. 1801 that an explanation became possible.

Rasmus Bartholin, Experimenta crystalli islandici disdiaclastici quibus mira & insolita refractio detegitur. Hafniæ 1669. English translation: Experiments with the double refracting Iceland crystal which led to the discovery of a marvelous and strange refraction, tr. by Werner Brandt. Westtown, Pa., 1959.

Bartholin was also the first to document the physical characteristics of trisomy 13, Patau Syndrome, in medical literature.

Important Facts

1. Dates Born: Roskilde, Denmark, 13 Aug. 1625 Died: Copenhagen, 4 Nov. 1698 Dateinfo: Dates Certain Lifespan: 73

2. Father Occupation: Physician, Academic Caspar Bartholin, Physician, Academic. He died when Erasmus was four. No clear information on financial status.

3. Nationality Birth: Roskilde, Denmark Career: Denmark Death: Copenhagen, Denmark

4. Education Schooling: Copenhagen, B.A. and M.A.; Leiden; Padua, M.D. Taught initially by private teachers, then attended Latin school. 1642-4: Univ. of Copenhagen, B.A. in 1644. M.A. in 1647. Studied mathematics at the University of Leiden for several years beginning in 1645. 1651: studied mathematics in France and Italy, ultimately at Padua where he was Consiliarius for the German Nation and Vice-syndicus for the university. M.D., 1654 at Padua. 1654-6: travelled and studied in Italy.

5. Religion Affiliation: Lutheran.

6. Scientific Disciplines Primary: Mathematics, Optics Subordinate: Medicine, Astronomy Major contribution to science was his study of Icelandic spar. Writings in pure mathematics were fairly numerous but not of great importance. Wrote a little on medicine. Observed the comets of 1665 and other astronomical objects, and published about this topic.

7. Means of Support Primary: Academia, Patronage, Government Professor of mathematics at Copenhagen, 1657. Extraordinary chair of medicine, 1657. Royal Mathematician, 1667. Ordinary chair of medicine, 1671. Teacher to Prince Joergen, 1671. Dean of the faculty of medicine. Librarian. Rector in three different years. Royal physician. Privy concilor, Advisor to the chancellor, then minister of justice.

8. Patronage Type: Court Official He was supported and directed by Frederick III of Denmark to prepare for publication of collected manuscript observations of Tycho Brahe. In addition, all of the connections to the court, and the various appointments above.

9. Technological Involvement Type: Medical Practice As a physician, he introduced quinine in the fight against malaria.

10. Scientific Societies Memberships: None He worked with Ole Roemer on Tycho's manuscripts. He worked with Niels Stensen on crystallography.

External links

* O'Connor, John J.; Robertson, Edmund F., "Rasmus Bartholin", MacTutor History of Mathematics archive, University of St Andrews, http://www-history.mcs.st-andrews.ac.uk/Biographies/Bartholin.html .