KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 

 TE AMSTERDAM. 



PROCEEDINGS OF THE iMEETJNG 

 of Saturday November 25, 1911. 



(Translated from : Verslag van de gewone vergadering der Wis- en Natuurkundige 

 Afdeeling van Zaterdag 25 November 1911, Dl. XX). 



(DOlSTTJEilSTTS. 



E. E. Mogkndokff: ".Siimiiiational and differential vibrations in line spectra". (Commiini- 



cated by Prof. P. Zekman), p. 470. 

 Hendrik dk VrikS: "On the conoids belonging to an arbitrary surface". (1st part), p. 481. 

 P. H. SciiocTE : "Surfaces, twisted curves and groups of points as loci of vertices of certain 



systems of cones", (First paper), p. 495. 

 .1. D. VAX DF.u Waals: "Contribution to the theory of the binary mixtures", XVI, p. .')04. 

 D. J. KoRTEWEG and F. A. II. SciireinemakkrS: "General considerations on the curves of 



contact of .surfaces with cones, with application to the lines of saturation and binodal lines 



in ternary systems", ji 510. 

 J. C. Kaptkyn: "The Milky way and the star-streams", p. 52 4. 

 A. Smits: "The system Iron — Carbon". (Communicated by Prof. A. F. IIollkman), p. 5.30. 



F. E. C. ScHEFFER and J. P. Treuh: "Determinations of vapour tensions of nitrogen tetroxide". 



(Communicated by Prof. A. F. Hollemax), p. 536. 



D. Moxtesaxo: "The theory of bilinear complexes of conies". (Communicated by Prof Jan 

 DK Vries), p. 550. 



K. Martix: "On geological records on the South- West coast of New Guinea", p. 555. 



F. il. Jaeger: "Contribution to tlie knowledge of the natural sulfo-antimonites", I. (Commu- 

 nicated by Prof. P. VAN Ko.mbl'ROHj, p. 555. 



F. M. Jaeger and II. S. van Klooster: "Contribution to the knowledge of sulfo-antimonites", 

 II. (Communicated by Prof. P. van IIo.mburgii), p. 555. 



32 



Proceedings Royal Acad. Amsterdam, Vol. XIV. 



