KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 



TE AMSTERDAM. 



PROCEEDINGS 



VOLUME XX 

 N°. 9 and 10. 



President: Prof. H. A. LORENTZ. 

 Secretary : Prof. P. Zeeman. 



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

 Natuurkundige Afdeeling," Vol. XXVI). 



CONTENTS. 



Miss L. Kaiser : "On the refractory stage of tfie frog's gastrocnemius". (Communicated by Prof. 

 Q. VAN RljNBERK), p. 1214. 



A. W. K. DE JONO: "The double acid from normal- and allo-cinnamic acids". 'Communicated by 



P. VAN ROMBURGH , p. 1230. 



V. WlLLEM: "On the Respiratory Movements of the Frog." (Communicated by Prof. G. VAN RljNBERK), 

 p. 1234. 



Gunnar Nordstrom: "On the Energy of the Gravitation Field in EiNSTEIN's Theory". (Communi- 

 cated by Prof. H. A. LORENTZi, p. 1238. 



B. P. HaalmeijeR: "On Elementary Surfaces of the Third Order". (Fourth communication). (Com- 



municated Prof. L. E. J. BROUWER), p. 1246. 

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



J. D. VAN DER WAALS), p. 1254. 

 H. Zwaardemaker and H. Zeehuisen: "On the Electric Nebulae of Antipyretica", p 1272. 

 W. J. DE HAAS: "On the diffraction phenomenon caused by a great number of irregularly distributed 



apertures or opaque particles'. 'Communicated by Prof. H. A. LORENTZ), p. 1278. 

 W. DE SITTER: "Outlines of a new theory of Jupiter's satellites", p. 1289; (continued) p. 1300. 

 W. DE SlTTER: "Further remarks on the solutions of the field-equations of EiNSTEIN's theory of 



gravitation", p. 1309. 

 W. VAN Bemmelen: "The Atmospherical Circulation above Australasia according to the Pilot- 

 balloon-Observations made at Batavia '. (Communicated by Dr. J. P. van DER Stok), p. I3I3. 



(With one table). 

 EUO. DUBOIS: "On the Relation between the Quantities of the Brain, the Neurone and its Parts, 



and the Size of the Body." (Communicated by Prof. H. ZWAARDEMAKER), p. 1328. 



84 

 Proceedings Royal Acad. Amsterdam. Vol. XX. 



