KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 



TE AMSTERDAM. 



PROCEEDINGS 



VOLUME XXi 

 N°. 5. 



President: Prof. H. A. Lorentz. 

 Secretary: Prof. P. Zeeman. 



(Translated from : "Verslag van de gewone vergaderingen der Wis- en 

 Natuurkundige Afdeeling," Vol. XXVI and XXVII). 



CONTENTS. 



D. J. HULSHOFF POL: "Our equilibrium-organ". (Communicated by Prof C. Winkler), p. 626. 



D. J. HULSHOFF POL: "Cerebellar ataxia as disturbance of the equilibrium-sensation". (Communi- 

 cated by Prof. C. Winkler», p. 637. 



J. J. VAN LaaR: "On the Heat of Dissociation of Di-atomic Gases in Connection with the Increased 

 Valency-Attractions l A of the Free Atoms". (Communicated by Prof. H. A. LORENTZ\ p. 644. 



P. G. Cath: "On the measurement of very low temperatures. XXIX. Vapour-pressures of oxygen 

 and nitrogen for obtaining fixed points on the temperature-scale below 0° C". (Communicated 

 by Prof. H. Kamerlingh Onnes), p. 656. 



F. E. C. SCHEFFER: "On Phenyl Carbaminic Acid and its Homologues". Communicated by Prof. 

 BÖESEKEN), p. 664. 



J. J. HAAK and R. SiSSlNGH: "Experimental Inquiry into the Nature of the Surface-Layers in the 

 Reflection by Mercury, and into the Difference in the Optical Behaviour of Liquid and 

 Solid Mercury". (Communicated by Prof H. A. LORENTZ), p. 678. 



F. M. JAEGER and William thomas B. SC: "Investigations on Pasteur's Principle concerning the 

 Relation between Molecular and Crystallonomical Dissymmetry: VIII. On the spontaneous 

 Fission of racemic Potassium-Cobalti-Oxalate into its optically-active -Antipodes", p. 693. 



L. E. J. BROUWER: "Ueber eineindeutige, stetige Transforniationen von Flachen in sich". iSechste 

 Mitteilung), p. 707. 



EUO. DUBOIS: "The Significance of the Size of the Neurone and its Parts". (Communicated by Prof. 

 H. Zwaardemaker), p. 7li. 



A. Pannekoek: "Expansion of a cosmic gassphere, the new stars and the Cepheids". (Communi- 

 cated by Prof. W. DE SITTER), p. 730. 



J. D. VAN DER Waals Jr.: "On the Theory of the Friction of Liquids. (Communicated by Prof. J. 

 D. VAN DER Waals), p. 743. 



A. B. Droooleever FORTUVN: "On two Nerves of Vertebrates agreeing in Structure with the 

 Nerves of Invertebrates". (Communicated by Prof. J. B0EKE\ p. 756. 



K\e^''')': (Zv 



N. G. W. H. BEEGER: "Ueber die Teilkörper des Kreiskörpers K \e' /". (Zweiter Teil), p. 758, 

 (Dritter Teil), p. 774. (Communicated by Prof. W. Kapteyn). 



41 



Proceedings Royal Acad. Amsterdam. Vol. XXI. 



