Change of Rigidity by Magnetization. 537 



tube, we may regard the liquid and the vapour as being 

 everywhere in approximate equilibrium. At the lower end, 

 since the pressure is atmospheric and the temperature scarcely 

 below 100°, there can be little alcohol ; for similar reasons 

 at the upper end there cannot be much water, although the 

 exclusion is here less complete on account of the peculiar 

 character of the curve representing the relation of com- 

 positions at this extreme. 



Experiments were tried with four different strengths of 

 mixture — 20, 40, 60, and 75 per cent, of alcohol. In all 

 cases the water was collected nearly pure, never containing 

 more than \ per cent. o£ alcohol. The alcoholic part con- 

 densed from the upper end varied but little. The weakest 

 (from the 20 per cent, mixture) was of 89 per cent., and the 

 strongest was of 90*3 per cent. All strengths are given by 

 weight, and were calculated by Mendeleef's tables from the 

 observed specific gravities with suitable temperature cor- 

 rection. The watery constituent which, not having been 

 evaporated, sometimes looked a little dirty, was usually redis- 

 tilled so as to obviate any risk of its purity being over- 

 estimated. In some cases it could not be distinguished from 

 pure water. 



The apparatus illustrates very well the principles of ideal 

 distillation, and its performance may be regarded as satis- 

 factory. When once the conditions, as to preliminary 

 heating (if necessary) and as to rate of feed, have been found 

 for a particular mixture, the continued working is almost 

 self-acting, or at any rate could be made so without much 

 difficulty ; and it is probable that separations, otherwise very 

 troublesome, could be easily effected by use of it. 



LX. Change of the Modulus of Rigidity of Ferromagnetic 

 Substances by Magnetization. By K. Honda, Rigakushi, 

 S. Shimizu, Riga/cushi, and S. Kusakabe, Rigahishi*. 



1. ~\\/^E have already seen that the change of elasticity by 

 T T magnetization is not so small as oenerallv admitted. 

 The present experiments deal with the change of rigidity by 

 magnetization. The investigation is especially important 

 inasmuch as the change of rigidity is reciprocally related to 

 that of magnetization by torsion. 



In the course of his experiments on the mutual relations 

 between torsion and magnetization, Gr. Wiedemann f observed 



* Communicated by Prof. Nagaoka. ■ 

 f Wiedemann's Electricitat, iii. p. 796. 



Phil. Mag. S. 6. Vol. 4. No. 23. Nov. 1902. 2 N 



