Heike Kamerlingh Onnes when his notebook was deciphered a century later). He reported that ""Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state"". He published more articles about the phenomenon, initially referring to it as ""supraconductivity"" and, only later adopting the term "superconductivity". Kamerlingh Onnes received widespread recognition for his work, including the 1913 Nobel Prize in Physics for (in the words of the committee) ""his investigations on the properties of matter at low temperatures which led, "inter alia", to the production of liquid helium"". Some of the instruments he devised
Heike Kamerlingh Onnes helium, using several precooling stages and the Hampson–Linde cycle based on the Joule–Thomson effect. This way he lowered the temperature to the boiling point of helium (−269 °C, 4.2 K). By reducing the pressure of the liquid helium he achieved a temperature near 1.5 K. These were the coldest temperatures achieved on earth at the time. The equipment employed is at the Boerhaave Museum in Leiden. In 1911 Kamerlingh Onnes measured the electrical conductivity of pure metals (mercury, and later tin and lead) at very low temperatures. Some scientists, such as William Thomson (Lord Kelvin), believed that electrons flowing through