Diamagnetic Susceptibility of Heavy Water

Abstract

THE diamagnetic susceptibility of heavy water has been measured by Selwood and Frost¹ using a specimen only 92 per cent pure, and by Cabrera and Fahlenbrach² with a 99 per cent pure specimen. A specimen of 99.2 per cent purity having recently become available, it was thought worth while to measure the susceptibility by Gouy's method, using apparatus already set up for other investigations of which details have appeared elsewhere³. Two specimen tubes were used containing approximately 1.32 gm. and 1.01 gm. of ordinary water to their respective filling marks. The procedure was to take a reading with ordinary water in the tube and then with heavy water. Equal volumes of ordinary and heavy water were delivered into the tube from a specially constructed pipette. In this way measurements were made upon three samples in each tube, the mean results being 0.649 ± 0.001(3) and 0.649 ± 0.001(0) in units of 10⁶, for the two tubes, obtained by taking the susceptibility of ordinary water to be 0.720 at 20° C. The final mean value, corrected for the presence of ordinary water, is 0.648 ± 0.001(2) at 20° C.; the average deviation from the mean is given in each case.