190 BELL SYSTEM TECHNICAL JOURNAL 



temperature gradient necessary for the continuous growth of the crys- 

 tal. The orientation of the crystal with respect to the axis of the bar 

 may be chosen at will. 



Magnetic Properties of Single Crystals of Silicon Iron}'' H. J. 

 Williams. The magnetization curves for the [100], [110] and [111] 

 directions of single crystals of iron containing 3.85 per cent silicon were 

 obtained from single crystal specimens cut in the form of hollow 

 parallelograms so that the sides of each specimen were parallel to the 

 tetragonal, digonal or trigonal axes, respectively. This method avoids 

 the errors due to demagnetizing fields, inherent in previous measure- 

 ments on single crystals. In addition to the well-known anisotropy at 

 magnetizations above half of saturation, the data show for the first 

 time considerable anisotropy at low magnetizations. A maximum 

 permeability of 1,380,000, by far the highest ever reported for silicon 

 iron, was observed in the [100] specimen after careful annealing. 

 The magnetic anisotropy constants K\ and K^ were obtained from the 

 magnetization curves and from torque measurements on a disk cut 

 parallel to a (110) plane. 



The Quest of Vitamin Bi}^ R. R. Williams. An account is given 

 in semi-popular form of the events which led to a recognition of a 

 dietary deficiency as the cause of Oriental beriberi. The steps are 

 indicated which led to the isolation and synthesis of the lacking sub- 

 stance which is now known as vitamin Bi. The author began his re- 

 searches on this subject in Manila in 1910 and has prosecuted them 

 continuously since that time. In 1936 he had the gratification of 

 effecting with Dr. J. K. Cline of Merck and Company a practical 

 synthesis of this vital compound so that it is now produced artificially 

 much more cheaply than it can be obtained in pure form from nature. 



In presenting his work on the architecture of the molecule and its 

 artificial reconstruction from synthetic sources, the author endeavors 

 to make clear to the layman by analogy and otherwise the methods 

 which the organic chemist employs in such a study. The highly in- 

 ferential deductions concerning complex interatomic relationships 

 which result from tearing the natural molecule apart reach a dramatic 

 verification only when one finds he has actually reproduced in the 

 laboratory the precise product of nature's art. 



" Phys. Rev., October 1, 1937. 



'* Jour. Franklin Institute, November 1937. 



