The Dutch physicist Heike Kamerlingh-Onnes, 1853- 1926. Kamerlingh-Onnes studied under Bunsen and Kirchhoff in Heidelberg, and in 1882 he became professor at Leyden University. He worked on the properties of matter at low temperatures. He obtained liquid helium by cooling it using liquid hydrogen, followed by expansion, and found that it did not solidify even at a temperature of just below 1 Kelvin. In 1911 he found that metals such as mercury, tin and lead at very low temperatures become superconductors, with near-zero electrical resistance. He won the Nobel Prize for his work in low temperature physics in 1913.