FOREWORD BY THE EDITORS 



The purpose of this Series on the Progress of Research in 

 Holland during the war is to show the world that scientists in 

 the Netherlands have remained active during the five years of 

 German occupation. The publication of monographs by the 

 most representative research workers was already planned in 

 the first years of the war, as a token of the undaunted spirit 

 of the Netherlands. 



In spite of the ever-growing burden of oppression and 

 starvation research was continued intensively in all directions. 

 Most of the material now published in this series was, for 

 obvious reasons, kept a secret during the war. 



It being the Editors' aim to present these monographs as 

 early as posj^ible after war, the majority of them were 

 prepared whilst the war was still on. Authors were therefore 

 expected to give mainly the results of their own investigations 

 without exhaustive reference to the Anglo-Saxon literature 

 which would not be available to them until after the war 



The hope is expressed that the publication of this series will 

 further intensify the interest shown by the allied nations in 

 the fate of the Netherlands, demonstrating, as it does, the 

 whole-hearted preparedness of our nation to contribute to 

 the progress of mankind. 



The Editors, 



Dr Ir R. Houwink 



Dr J. A. A. Ketelaar 



Amsterdam, on V.E.-day, 8th May 1945. 



