KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 



TE AMSTERDAM. 



PROCEEDINGS 



VOLUME XXI 

 N°. 6 and 7. 



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. 



C. Spruit P.Pzn.: "On the influence of electrolytes on the motility of Chlamydomonas variabilis 



Dangeard". (Communicated by Prof. Went), p. 782. 

 H. A. BROUWER: "On the Non-existence of Active Volcanoes between Pantar and Dammer 



lEast Indian archipelago), in Connection with the Tectonic Movements in this Region". iCom- 



municated by Prof. G. A. F. MOLENGRAAFF', p. 795. 

 H, A. BROUWER: "On the Age of the Igneous Uocksin the Moluccas''. (Communicated by Prof. G, A. F. 



MOLENQRAAFF), p. 803. 

 H. A. BROUWER: "On Reefcaps". (Communicated by Prof. G. A. F. MOLENQRAAFF), p. 816. 



F. E. C. SCHEFFER: "On the Occurrence of Solid Substance in Binary Mixtures with Unmixing" I. 



(Communicated by Prof. J. BÖESEKEN), p. 827. 

 J. E. VerschaffelT: "On the shape of large liquid drops and gas-bubbles and the use made 



of them for the measurement of capillary constants". (Communicated by Prof. KAMERLINGH 



ONNES', p. 836. 

 Bug. DUBOIS: "Comparison of the Brain Weight in Function of the Body Weight, between the 



Two Sexes''. 'Communicated by Prof. H. ZWAARDEMAKER, p. 850. 

 W. J. A. SCHOUTEN; "The Distribution of the Absolute Magnitudes among the Stars in and about 



the Milky Way". Second Communication'. (Communicated by Prof. J. C. KAPTEYN), p. 870. 



(With one plate 

 |. WOLTJER Jr.: "The longitude of Hyperion's pericentre and the mass of Titan". (Communicated 



by Prof. W. DE SlTTER), p. 881. 

 J. BÖESEKEN. Miss Q. W. Tergau and A. C. Binnendijk: "On the influence of some salts on the 



dyeing of cellulose with Benzopurpurin 4B", p. 893. 

 J. BÖESEKEN and W. M. DEERNS: "The mutual influence on the electrolytic conductivity of gallic 



tannic acid and boric acid in connection with the composition of the tannins'', p. 907. 

 L. S. Ornstein and F. Zernike: 'Magnetic properties of cubic lattices". (Communicated by Prof. 



H. A. Lorentz), p. 9U. 

 L. S. Ornstein and H. C. Burger: "On the theory of the Brownian motion". (Communicated by 



Prof. H. A. Lorentz , p. 922. 



G. HOLST and E. OosterhuiS: "The audion as an amplifier". (Communicated by Prof. H. A. Lorentz», 



p. 932. 

 L. E. J. BROUWER: "Remark on the plane translation theorem', p. 935. 

 J. K. A. Wertheim SalomonsON: "A new ophthalmoscope", p. 937. 

 J. K. A. Wertheim SALOMONSON and Mrs. Ratu Langi-Houtman: "Tonus and faradic tetanus", 



p. 941. With one platei. 

 Erik Agduhr: „is the post-embryonal growth of the nervous system due only to an increase in 

 size or also to an increase in number of the neurones?" (Communicated by Prof. J. BOEKE), 



p. 944. 

 Errata, p. 966. 



51 

 Proceedings Royal Acad. Amsterdam. Vol. XXI. 



