KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 
TE AMSTERDAM. 
PROGGEDENGS 
VOLUME XX11I 
Ne. 5. 
President: Prof. H. A. LORENTZ. 
Secretary: Prof. P. ZEEMAN. 
(Translated from: ‘Verslag van de gewone vergaderingen der Wis- en 
Natuurkundige Afdeeling,’ Vols. XXVIII and XXIX). 
CONTENTS. 
F. M. JAEGER: “Some Remarks concerning the Röntgenograms obtained by means of Mica-Piles 
composed by crossed Lamellae”, p. 676. 
A. SMITS: “On the Validity of the Law of Partition for the Equilibrium between a Mixed-Crystal 
Phase and a Coexisting Liquid”. I. (Communicated by Prof. P. ZEEMAN), p. 679. 
A. SMITS and J. SPUYMAN: “The Thermo-electric Determination of Transition Points”. I. (Commu- 
nicated by Prof. P. ZEEMAN), p. 687. ; 
H. C. BURGER: “Observations of the Temperature during Solidification’. (Communicated by Prof. 
H. A. LORENTZ), p. 691. 
W. EINTHOVEN: “On the Observation and Representation of Thin Threads”, p. 705. 
A. PANNEKOEK: “The Distance of the Dark Nebulae in Taurus”. (Communicated by Prof. J. C. 
KAPTEYN), p. 707. 
A. PANNEKOEK: “Further Remarks on the Dark Nebulae in Taurus”. (Communicated by Prof. J. C. 
KAPTEYN), p. 720. 
G. HOLST and E. OOSTERHUIS: “The so-called cyanogen-bands”. (Communicated by Prof. H. KAMER- 
LINGH ONNES), p. 727. 
A. D. FOKKER: “The geodesic precession: a consequence of EINSTEIN’s theory of gravitation”. 
(Communicated by Prof. H. A. LORENTZ), p. 729. 
J. VERSLUYS und R. DEMOLL: “Die Verwandtschaft der Merostomata mit den Arachnida und den 
anderen Abteilungen der Arthropoda”. (Communicated by Prof. MAX WEBER), p. 739. 
A. A. HIJMANS VAN DEN BERGH and P. MULLER: “On Serum-lipochrome”, (Part II), p. 766. 
J. M. BURGERS: “On the resistance of fluids and vortex motion”. (Communicated by Prof. P. 
EHRENFEST), p. 774. 
P. E. VERKADE: “On the Action of Micro-organisms on Organic Compounds. II. The Solubility 
of some Organic Acids in Fatty Oils”. (Communicated by Prof. J. BOESEKEN), p. 783. 
H. C. BURGER and P. H. VAN CITTERT: “Measurements on the Intensity of Spectrum Lines by the 
Aid of the Echelon”. (Communicated by Prof. W. H. JULIUS), p. 790. 
K. W. RUTGERS: “Degenerations in Linear Systems of Prane Cubics”. (Communicated by Prof. 
JAN DE VRIES), p. 797. 
RASSA RIWLIN: “Photographic Absorption- and Extinction-Measurements. Contributions to the 
study of liquid crystals. V. Extinction-measurements”. (Communicated by Prof. W. H, JULIUS), 
p. 807. 
F. BERNSTEIN (Göttingen): “Die Integralgleichung der elliptischen Thetanullfunktion. Zweite Note: 
Allgemeine Losung”. (Communicated by Prof. L. E. J. BROUWER), p. 817. 
44 
Proceedings Royal Acad. Amsterdam. Vol. X XIII. 
