In the sixteenth century science was taught as 'natural philosophy'. The seventeenth century saw the institution of the University Chairs of Mathematics and Botany, followed the next century by Chairs of Natural History, Astronomy, Chemistry and Agriculture. During the eighteenth century, the University was a key contributor to the Scottish Enlightenment and it educated many of the most notable scientists of the time. It was Edinburgh's professors who took a leading part in the formation of the Royal Society of Edinburgh in 1783. In 1785, Joseph Black, Professor of Chemistry and discoverer of carbon dioxide, founded the world's first Chemical Society. The nineteenth century was a time of huge advances in scientific thinking and technological development. The first named degrees of Bachelor and Doctor of Science were instituted in 1864, and a separate 'Faculty of Science' was created in 1893 after three centuries of scientific advances at Edinburgh. The Regius Chair in Engineering was established in 1868, and the Regius Chair in Geology in 1871. In 1991 the Faculty of Science was renamed the Faculty of Science and Engineering, and in 2002 it became the College of Science and Engineering. All teaching is now done over two semesters (rather than 3 terms) – bringing the timetables of different Schools into line with one another, and coming into line with many other large universities (in the US, and to an increasing degree in the UK as well). The University of Edinburgh is a member of the Russell Group of research-led British universities and one of several British universities to be a member of both the Coimbra Group and the LERU (League of European Research Universities). The university is also a member of Universitas 21, an international association of research-led universities. Edinburgh is a member of the 'Sutton 13' of top ranked Universities in the UK. Beside, the university maintains historically strong ties with the neighbouring Heriot-Watt University for teaching and research. Moreover, the University of Edinburgh has around 300 student exchange partners in nearly 40 countries world-wide including exchange programs with Peking University, Washington University in St. Louis, Karolinska Institute, and Caltech. As of 2019, Edinburgh had the 8th highest average entry qualification for undergraduates among UK universities, with new students averaging 189 UCAS points, equivalent to just above AAAaa in A-level grades. The university gives offers of admission to 20% of its 18 year old applicants, the 5th lowest amongst the Russell Group. As the number of places available for Scottish and EU students are capped by the Scottish Government since students do not pay tuition fees, students applying from the UK and outside of the European Union have a higher likelihood of an offer.