ABSTRACT
The road by which Polanyi came to metallurgical research is by no means the usual one. In the year 1920, R. O. Herzog and Scherrer1 had observed that the cellulose in plant fibres has a crystalline structure. By irradiation of a parallel bundle of fibres, using a perpendicular monochro matic X-ray beam, they obtained diagrams which did not exhibit uniform density of the Debye-Scherrer circles, and could not therefore be explained by random orientation of the micro-crystallites. The circles contained maxima of density only at particular points (4-and 2-point systems), the position of which did not change, even when the bundle was rotated about its vertical axis. If, on the other hand, the bundle was irradiated parallel to its axis, the uniform density characteristic of a micro-crystalline struc ture with random distribution was obtained. The interpretation of these ‘fibre diagrams’ in terms of the partial parallel orientation of the crystal lites, and the reason for the occurrence of this orientation: these were the problems which Polanyi had undertaken to investigate at Herzog’s sug gestion-an investigation which he pursued with great originality as leader of a small group of enthusiastic collaborators at the Kaiser-Wilhelm Insti tute for Fibre Research in Berlin-Dahlem.
