FROM YOUTH TO PROFESSOR 



sports; hockey in winter, and tennis during the remainder of the year. 

 In tennis he excelled, and in those days he was one of the strongest 

 players in Holland. The crowning glory came when, around 1910, 

 he was a member of the Dutch team that was to play against a Belgian 

 one, and won both singles matches. Soon thereafter he put his racket 

 away, however, so that he could devote himself exclusively to his 

 studies ! 



From 1910-1916 Kluyver was assistant at the Laboratory for Micro- 

 scopical Anatomy, later renamed Laboratory for Technical Botany. 

 It was a period during which not many industrial positions were open. 

 Moreover, Kluyver wanted to spend at least some years in pure re- 

 search; and in Van Iterson's institute he had a splendid opportunity 

 to acquaint himself with various aspects of botany and eventually to 

 master the field. The first two years offered scant opportunity for in- 

 vestigations of his own. He assisted with everything pertaining to the 

 teaching functions of the laboratory, such as the preparation of lecture 

 demonstrations and of the laboratory courses. This involved a great 

 deal of work, particularly because the institute's staff could boast only 

 one technician and a single gardener. Furthermore, he assisted in the 

 laboratory courses, and partly supervised the work of the students 

 specializing in the field. And when, in the spring of 191 1, Van Iterson 

 travelled to the Dutch East Indies as a delegate of the Netherlands' 

 Government to the International Fibre Congress in Surabaja, Kluy- 

 ver was left in complete charge of the laboratory for several months. 



During the summer vacation of 191 1 he spent some months working 

 under Prof. Dr. Hans Molisch at the Plant-Physiological Institute of 

 the University of Vienna. This led to a paper entitled 'Observations 

 on the effect of ultraviolet radiation on higher plants' [191 1]. He rel- 

 ished the beauties of Vienna, and returned home via the Dolomites. 



It was logical to expect that Kluyver would attempt to prepare a 

 Doctor's dissertation. In the spring of 191 2 he began an investigation 

 of biochemical sugar determinations, with the aim of elaborating this 

 subject and, if possible, using the results for a thesis. For more than 

 two years Kluyver threw himself into the problem with all his energy 

 and endurance. Meanwhile he had moved back to Delft so that he 

 could spend all his time on this study. This was particularly necessary 

 because he regularly had to work evenings in the laboratory, and 



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