KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 



TE AMSTERDAM. 



PROCEEDINGS 



VOLUME XX 

 N°. 3. 



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. C. Kluyver: "On hyperelliptic integrals of deficiency p— 2, reducible by a transformation of 

 order r~4", p. 330. 



J. P. Treub: "On the Saponification of Fats". II. (Communicated by Prof. S. HOOGEWERFF), p. 343. 



Annie van Vleuten: "Do the forces causing the diurnal variation of terrestrial magnetism possess 

 a potential?" (Communicated by Dr. J. P. VAN DER Stok), p. 358. 



Annie van Vleuten : "On the question whether the internal magnetic field, to which the diurnal 

 variation in terrestrial magnetism is partly ascribed, depends on induced currents". (Communi- 

 cated by Dr. J. P. VAN DER STOK), p. 361. 



J. E. Verschaffelt: "The equation of state of an associating substance". (Communicated by Prof. 

 H. KAMERLINGH ONNES), p. 365. 



H. I. Waterman r "Influence of different compounds on the destruction of monosaccharids by sodium- 

 hydroxide and on the inversion of sucrose by hydrochloric acid." II. (Communicated by Prof. 

 J. BÖESEKEN), p. 382. 



A. Smits, G. Meyer, and R. Th. Beck: "On Black Phosphorus". II. (Communicated by Prof. S. 

 HOOGEWERFF), 392. 



A. Smits and C. A. LOBRV DE Bruyn: "On the Electro-Chemical Behaviour of Nickel". (Communi- 

 nicated by Prof. S. HOOGEWERFF), p. 394. 



S. DE BOER: "On the transmission of stimula through the ventricle of frogs' hearts". (Communi- 

 cated by Prof. G. van Rijnberk), p. 404. 



Jan DE Vries : "Surfaces that may be represented in a plane by a linear congruence of rays'', p. 419. 



J. BÖESEKEN and H. W. HOFSTEDE: "Observations about hydration under the influence of Colloidal 

 Catalysers and how to account for this process", p. 424. tWith one plate). 



G. P. FRETS: "On Mendelian Segregation with the Heredity of Headform in Man". (Communicated 

 by Prof. C. Winkler), p. 435. 



H. B A. BOCKWINKEL: "Some Considerations on Complete Transmutation". (Third communication). 

 (Communicated by Prof. L. E. J. BROUWERi, p. 449. 



C. J. C. VAN Hoogenhuyze: "Researches relating to the Etiology of FebrisExanthematicus." (Com- 

 municated by Prof. C. Eykman), p. 465. (With one plate). 



F. ROELS: "Intercomparison of some results obtained in the Investigation of Memory by the Natural 

 and the Experimental Learning Method". (Communicated by Prof. C. WINKLER), p. 477. 



J. J. VAN LAAR: "On the Fundamental Values of the Quantities b and |/a for Different Elements, 

 in Connection with the Periodic System. V. The Elements of the Carbon and Titanium Groups", 

 (Communicated by Prof. H. A. LORENTZ), p. 492. 



J. J. VAN Laar: "Idem VI. The Alkali Metals" (Communicated by Prof. H. A. LORENTZ), p. 505. 



A. SMITS and J. GiLLlS: "On Milk-Sugar". L (Communicated by Prof. S. HOOGEWERFF), p. 520. 



22 



Proceedings Royal Acad. Amsterdam. Vol. XX. 



