the ecumenical movement. The university became prominent in the sciences in the 18th century with names such as the physician and botanist Carl Linnaeus (1707–1778), the father of biological and mineralogical taxonomy, and his numerous important pupils, the physicist and astronomer Anders Celsius (1701–1744), inventor of the Celsius scale the predecessor of the Celsius scale, and the chemist Torbern Bergman (1735–1784). Another scientist from this era is Emanuel Swedenborg (1688–1772), better remembered today as a religious mystic. Several of the elements were discovered by Uppsala scientists during this period or later. Jöns Jakob Berzelius, one of the fathers of modern chemistry, received his doctorate in medicine in Uppsala in 1804, but later moved to Stockholm. Uppsala scientists of the 19th century include the physicist Anders Jonas Ångström (1814–1874). During the 20th century, several Nobel laureates in the sciences have been Uppsala alumni or professors at the university. Many well-known Swedish writers have studied in Uppsala: Georg Stiernhielm (1598–1672) is often called the father of Swedish poetry. The poet and song composer Carl Michael Bellman (1740–1795), without doubt, the best-loved and best-remembered Swedish 18th-century poet, matriculated but left the university after less than a year. The writer, historian and composer Erik Gustaf Geijer (1783–1847), professor of history, and the poet Per Daniel Amadeus Atterbom (1790–1855), professor of poetry, were principal figures of early 19th-century Swedish romanticism. The less than happy experiences of the Uppsala student life of novelist and playwright August Strindberg (1849–1912), resulted in his Från Fjärdingen och Svartbäcken (1877), a collection of short stories set in Uppsala ("From Fjärdingen and Svartbäcken," the title refers to two districts in Uppsala). Other Uppsala alumni are the poet Erik Axel Karlfeldt (1864–1931), who refused the Nobel Prize for Literature in 1918 but received it posthumously in 1931, the novelist and playwright Pär Lagerkvist (1891–1974), Nobel laureate in 1951, and the poet and novelist Karin Boye (1900–1941), for whom one branch of the university library has been named. The Communist leader Ture Nerman (1886–1969) wrote a novel called Olympen, based on his experience as a student in Uppsala. International cooperation Uppsala University has signed student exchange agreements with about 400 universities across all parts of the world. It takes part in the Erasmus programme and the Nordplus programme. It also benefits from its membership in the Coimbra Group of universities. In May 2010 Uppsala joined the Matariki Network of Universities (MNU) together with