KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 



TE AMSTERDAM. 



PROCEEDINGS 



VOLUME XX 

 N°. 2. 



President: Prof. H. A. LoRENTZ. 

 Secretary: Prof. P. Zeeman. 



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

 Natuurkundige Afdeeling," Vol. XXV and XXVI). 



CONTENTS. 



J. J. VAN LAAR: "On the Critical Temperature and Pressure of Mercury and Phosphorus'. (Com- 

 municated by Prof. H. A. LORENTZ), p. 138. 



J. M. BURGERS: "Adiabatic Invariants of Mechanical Systems." I, II and III. (Communicated by 

 Prof. H. A. LORENTZ), p. 149, p. 158 and p. 163. 



J. M. BURGERS: "The spectrum of a rotating molecule according to the theory of quanta". (Com- 

 municated by Prof. H. A. LORENTZ), p. 170. 



H. Kamerlingh Onnes, C. a Crommelin and P. 0. Cath: "Isothermals of di-atomic substances 

 and their binary mixtures. XIX. A preliminary determination of the critical point of hydro- 

 gen", p. 178. 



H. I. Waterman : "Amygdalin as nutriment for Fusarium". (Communicated by Prof. J. BÖESEKEN), p. 185. 



H. ZWAARDEMAKER: "On the behaviour of the Uranium-heart towards Electric Stimulation, as 

 investigated by Mr. M. den Boer, p. 189. 



N. VOORHOEVE: "A hypothesis concerning the mutual relation between some hereditary abnormalities 

 that occur combined". 'Communicated by Prof. I. K. A. Wertheim Salomonson), p. 194. 



P. Ehrenfest: "in what way does it become manifest in the fundamental laws of physics that 

 space has three dimensions?" (Commumunicated by Prof. H. A. Lorentz), p. 200. 



W. J. H. Moll and L. S. Ornstein: "Contribution to the research of liquid crystals. 11. The 

 influence of the temperature on the extinction; further experiments upon the influence of the 

 magnetic field". (Communicated by Prof. W. H. JULIUS), p. 210. 



C. J. V. D. HORST: "The Fore-brain of Synbranchidae". (Communicated by Prof. Max Weber), p. 217. 



W. DE Sitter: "On the curvature of space", p. 229. 



F. M. JAEGER: "Investigations into PASTEUR'S Principle of the Connection between Molecular and 

 Crystallonomical Dissymmetry. III. Racemic and Optically Active Complex Salts of Trivalent 

 Rhodium", p. 244. 



F. M. JAEGER: "Ibid. IV. Racemic and Optically-active Complex Salts of Rhodium-tri-oxalic Acid," p. 263. 



F. M. JAEGER: "Two Crystallised, Isomeric rf-Fructose-Penta-acetates", p. 280. 



F. M. JAEGER and R. T. A. MEES: "On Complex Salts of Ferri-Malonic-Acid", p. 283. 



F. M. JAEGER and Jul. Kahn: "On some isomeric, complex cis- and frans-Diethylenediamine-Salts 

 of Cobaltum, and on Tri-ethylenediamine-Zinc-Chloride". p. 292. 



B. P. HAALMEIJER: "On Elementary Surfaces of the third order." (Second communication). (Com- 

 . municated by Prof. L. E. J. BrouweR), p. 304. 



E. H. BiiCHNER: "The boiling point line of the system: hexane-nitrobenzene." (Communicated by 

 Prof. A. F. HOLLEMAN), p. 322. 



1. K. A. WERTHEIM SALOMONSON: "Photography of the fundus of the human eye", p. 326. (With one 

 plate). 



10 



Proceedings Royal Acad. Amsterdam. Vol. XX. 



