Kuenen, Johannes Petrus

(b Leiden, Netherlands, 11 October 1866; d. Leiden, 25 September 1922)

physics.

Johan Kuenen was the son of Abraham Kuenen, professor of theology at the University of Leiden and Wiepkju Muurling, a daughter of W. Muurling, professor of theology at the University of Groningen. Juenen began his studies of physics at the University of Leien in 1884. In 1889 he was appointed assistant to H. Kamerlingh Onnes. He won his doctorate with a dissertation which, as a prize essay, had been awarded a gold medal in 1892. From 1893 until 1895 he served as conservator of the university physics laboratory; in the latter year, he went to England, where he worked with Sir William Ramsay in London and with Sir James Walker in Dundee, at the university of which town he was soon appointed professor of physics. He stayed at the University of Dundee until December 01906, when he was called back to Leiden to occupy a chair of physics. He held this post until his death.

Kuenen is known chiefly for his work on phase equilibria. The golden era of Dutch physics had been inaugurated in 1873 by J. D. van der Waals with his dissertation Over de continuiteit van den gasen vloeistoftoestand, in which the famous equation of state had been introduced. The foundation for many pioneering investigations on critical phenomena and phase equilibria, it led dutch physicists triumphs as the liquefaction and solidification of helium. Kuenen undertook his doctoral work to supply data for the theoretical research on binary mixtures that was then being conducted by van der Waals.

While pursuing this investigation, Kuenen discovered the phenomenon of retrograde condensation, which may be explained as follows. If the volume of a two (or multi-) component gaseous system, kept at constant temperature and pressure below critical conditions, is gradually reduced, condensation will start when a certain volume is reached; the amount of condensate will gradually increase upon further reduction in volume, until finally the entire system is liquefied. If, however, the composition of such a system lies between the compositions defined by the so-called true and pseudo critical points, the condensate formed upon reduction of the volume will disappear on continued reduction of the volume. This disappearance of the condensate is called retrograde condensation. The phenomenon finds a practical application in the recovery of gasoline from gas wells.

Kuenen devoted his entire scientific life to the study of phase relations, designing many instruments for use in this study and contributing numerous data. Although he excelled as an experimenter, he also found theoretical solutions to problems that arose from his own work or that of other. In addition, he contributed articles of popular nature on the progress of physics and its implications to the monthly magazine De Gids and wrote a history of physics in the Netherlands.

BIBLIOGRAPHY

I. Original Works. A list of Kuenen’s scientific papers has been complied by W. J. de Haas (see below).

His works include Mettingen betreffende het oppervlak van van der Waals voor mengsels van koolzuur en chloor methyl (Leiden, 1892); Theorie der Verdampfung und Vertion, vol. IV of G. Bredig, ed., Handbuch der angewandten chung der Gase und Flüssigkeiten und die Kontinuitätstheorie (Brunswick, 1907); Die Eigenschaften der Gase, vol. III of W. Ostwald, ed., handbuch der allegemeinen Chemie (Leipzig, 1919); and Het aandeel van Nederland in de ontwikkeling de rNatuurkunde gedurende de laatste 150 jaren (Gedenboek van het Bataafsch Genootschap der Proefondervindelijke Wijsbegeerte te Rotterdam, 1769–1919), privately prionted (Rotterdam, 1919).

II. Secondary Literature. On Kuenen and his work see W. J. de Hass, “Prof. Dr. J. P. Kuenen, ter nagedachtenis,”in Physica, 2 (1922), 281–287; and “Lijst van verhandelingen vanProfessor Dr. J. P. Kuenen,” ibid 342–344, a bibliography of Kuenen’s scientific papers; J. Herderschee, “abraham Kuenen,” in Nieuw Nederlandsch biografisch Woordenboek, II (Leiden, 1912), 734–735; H. Kamerlingh Onnes “Prof. J. P. Kuenen,” in Nature, 110 (1922), 673–674; and JH. A. Lorentz, “Kuenen als Natuurkundige,” in de Gids, 4th ser., 86 (1922), 209–215; and “John Kuenen (1866–1822), grafrede,” in P. Zeeman and A. D. Fokker, eds., H. A. Lorentz, Collected Papers, IX (The Hague, 1939, 404–406.

Peter W. Van der Pas