KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 
TE AMSTERDAM. 
PROCEEDINGS OF THE MEETING 
of Friday April 29, 1910. 
(Translated from: Verslag van de gewone vergadering der Wis- en Natuurkimdige 
Afdeeling van 29 April 1910, DL XVHI). 
OOSTTEITTa 
Jan de Vries: “On polar figures with respect to a ] 
J. G. Sleeswijk: “Contributions to the study of 
(Communicated by Prof. C. H. H. Spkonck), p. 
L. E. J. Brouwer: “On the structure of perfect sets 
M. W. Beijerinck : “Emulsion laevulan, the produ 
um-anaphylaxis” (4th Communication). 
■ points”. (Communicated by Prof. D. J. 
H. Kameriangh Onnes 
oxygen”, p. 799. (With one plate). 
. St. Lori a: “The magneto-optic KuRR-Effect in ferro magnetic compounds and alloys”. (Com¬ 
municated by Pro£ H. E. J. G. du Bois), p. 835. (With one plate). 
52 
