30 



knock against, and be hurt by, protruding stones, but af ter leaving 

 the building and contemplating at a distance its superb architecture, 

 the former visitor would be lost in rapture. 



The description of Beijerinck's activities in his academie period 

 would be incomplete, if no mention were made of the fact that a 

 quite considerable number of foreign scholars came to work some 

 time under Beijerinck's supervision. Amongst these there were se- 

 veral scientists who have gained a well-deserved reputation in their 

 special fields. The names of Issatchenko (Russia), Gran (Norway), 

 Kaserer (Austria), Stoklasa (Austria), Krzeminiewski (Poland), 

 Krainsky (Ukraine) and Melin (Sweden) may be recorded here. 



The professorship often weighed heavily upon Beijerinck. A1- 

 ready in 1905, following a rather serious difference of opinion with 

 one of his collaborators, he feit inclined to resign. This urge came 

 with new force a few years later, when many of his colleagues, such as 

 Professors Hoogewerff, Aronstein and Scheltema, had left. In 

 1912 the intention turned up again, but, when after great trouble the 

 laboratory at the Nieuwe Laan acquired a new annexe, he was again 

 able to enjoy the work, although it was still disappointing, after all 

 the material improvements, that only a few students came to work 

 with him. 



There is no doubt that in the second half of his professorship Beije- 

 rinck was often dissatisfied with his achievements. For instance, he 

 once exclaimed : "At Delft I have come to grief ! If I had remained at 

 Wageningen, I should have been ahead of Buchner with his discovery 

 of the press-juice, I should also have rediscovered the Mendelian laws, 

 and those are not the only things I have missed!" He apparently often 

 dreaded a decline in public recognition, and he also fancied that he 

 no longer came up to the demands of his position. Indeed there is 

 reason to think that by 1905 he had attained his scientific peak. This 

 may have partly been due to the circumstance that exploration of the 

 microbe world, which under Beijerinck's pioneering guidance had 

 led to so many remarkable discoveries, had by then entered on a new 

 and more settled phase. 



Other matters certainly contributed to Beijerinck's periodic 

 attacks of mental depression. In 1911 the early death of his friend 

 VAN 't Hoef, then professor at the University of Berlin, made a deep 

 impression on him. He at once went to Berlin, and also attended the 

 cremation at Ohlsdorff near Hamburg. 



Great was his distress when war broke out in 1914 and almost entir- 

 ely put a stop to his relations with foreign scientists. 



At various times he intimated that he feared approaching old age. 

 But, in spite of all his worries, Beijerinck did know many moments 

 of real happiness. Possessed of an urge after knowledge, an almost 

 Dionysian joy often came over him when his experiments were suc- 

 cessful. Then his brown eyes would glitter, and, with a staring look 



