XVIII CONTENTS 
Physics. J. J. van LAAR: “On apparent thermodynamic discontinuities in connection 
with the value of the quantity 4 for infinitely large volume’’. 606. 
— Miss H. J. Former: “A new electrometer, especially arranged for radio-active 
investigations”. 659. 
- — G.J. Erras: “On the structure of the absorptionlines D, and JD”, 720. 
— G. J, Erras: “The lowering of the freezing point in consequence of an elastic 
deformation’’. 732. 
— G.J. Extras: “The effect of maguetisation of the electrodes on the electromotive 
force”. 745. 
— L. 8. ORNSTEIN: “On the theory of the string-galvanometer of ErntHoven”’. 784. 
— L. S. Ornstein and F. ZERNIKE: “Accidental deviations of density and opales- 
cense at the critical point of a single substance”. 793. 
— F. E. C. Scuerrer: “On unmixing in a binary system for which the three 
phase pressure is greater than the sum of the vapour tensions of the two compo- 
nents”. 834, 
— Mrs. T. EHRENFEST—AFANASSJEWA: “Contribution to the theory of corresponding 
states”. 840. 
— P. Exrenrest and H. KAMERLINGH ONNEs: “Simplified deduction of the 
formula from the theory of combinations which PLANcK uses as the basis of his 
radiationtheory”. 870. 
— H. vu Bors: “The universality of the Zeeman-effect witk respect to the STARK- 
effect in canal-rays”. 873. 
— J. J. van Laar: “The calculation of the molecular dimensions from the suppo- 
sition of the electric nature of the quasi-elastic atomic forces”. 877. 
— W. H. Kersom and H. KAMERLINGH Onnes: “The specific heat at low tempe- 
ratures. I. Measurements on the specific heat of lead between 14° and 80° K. 
and of copper between 159 and 22° k.” 894. 
— J. P. Kuenen: “On the measurement of the capillary pressure in a soap-bubble”. 
946. 
— H. KAMERLINGH ONNEs, C. Dorsman and G. Horst: “Isothermals of di-atomic 
substances and their binary mixtures. XV. Vapour pressures of oxygen and critical 
point of oxygen and nitrogen”. 950. 
— E. Maratas, H. KAMERLINGH ONNEs and U, A. CROMMELIN : “The rectilinear 
diameter of nitrogen”. 953, 
— ©, A. CROMMELIN: “Isothermals of di-atomic substances and their binary mixe- 
tures. XVI. Vapour pressures of nitrogen between the critical point and the 
boiling point”. 959, 
= J. Droste: “On the field of a single centre in E1nsTEtn’s theory of gravitation”, 
998, 
— J. P. Kuenen: “The diffusion coefficient of gases and the viscosity of gase 
mixtures”. 1068, 
— H, Terrope: “Theoretical determination of the enttopy constant of gases and 
liquids”. 1167. 
