KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 
TE AMSTERDAM. 
PROCEEDINGS 
VOLUME XXIII 
Ne, 4. 
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. 
JAN DE VRIES: “An Involutory Transformation of the Rays of Space which is defined by two Involutory 
Homologies”, p. 462. 
JAN DE VRIES: “An Involution of Rays defined by a Congruence of REYE and an Involutory 
Homology”, p. 466. 
TH. WEEVERS: “On the Calcifuge Plants of the Inland Dunes of the Island of Goeree”. (Communicated 
by Prof. F. A. F. C. WENT), p. 475. 
R. MAGNUS and U. G. BIJLSMA: “On the Pharmacological Action of Isoamylhydrocuprein (eukupin) 
and Isoctyl hydrocuprein (vuzin)”, p. 481. 
W. STORM VAN LEEUWEN and J. ZEYDNER: “On Adsorption of Poisons by Constituents of the 
Animal Body. II. The Adsorbent Power of Rabbit’s Serum for Atropin”. (Communicated by Prof. 
R. MAGNUS), p. 486. 
L. RUTTEN: “On the Occurrence of Halimeda in Old-Miocene Coastreefs of East-Borneo”, p. 506. 
A. DE KLEYN: “On the Effect of Tonic Labyrinthine and Cervical Reflexes upon the Eye-muscles”. 
(Communicated by Prof. R. MAGNUS), p. 509. 
W.H. JULIUS and P. H. VAN CITTERT: “The General Relativity Theory and the Solar Spectrum”, p. 522. 
S. DE BOER: “On Fibrillation of the Heart. (Part. III). Ventricular Fibrillation and “Gehäufte” 
Extrasystoles of the Ventricle excited by the “Erregung” consequent on an Artificial Auricular 
Systole”. (Communicated by Prof. I. K. A. WERTHEIM SALOMONSON), p. 533. 
S. DE BOER: “On the Artificial Extra-pause of the Ventricle of the Frog’s Heart”. (Communicated 
by Prof. W. EINTHOVEN), p. 542. 
S. DE BOER: “On Artificial and Spontaneous Changes of Rhythm in the Bled Frog’s Heart”. (Com- 
municated by Prof. W. EINTHOVEN), p. 552. 
H. A. BROUWER: “Crystallization and Resorption in the Magma of the Volcano Ruang. (Sangi Islands)”. 
(Communicated by Prof. G. A. F. MOLENGRAAFF), p. 561. 
H. A. BROUWER: “Fractures and Faults near the Surface of Moving Geanticlines”. I. (Communicated 
by Prof. G. A. F. MOLENGRAAFF), p. 570. 
CLARA ZOLLIKOFER: “Ueber die tropistische Wirkung von rotem Licht auf Dunkelpflanzen von 
Avena sativa’. (Communicated by Prof. F. A. F. C. WENT), p. 577. 
J. WOLFF: “On the Theorem of Picard”. (Communicated by Prof. L. E. J. BROUWER), p. 585. 
W. VAN DER WOUDE: “On the Motion of a Fixed System”. (Communicated by Prof. J. CARDINAAL), 
p. 589. 
J. E. W. IHLE and G J. VAN OORDT: “On the larval development of Oxyuris equi (Schrank)”. (Communi- 
cated by Prof. C. PH. SLUITER), p. 603. 
I. K. A. WERTHEIM SALOMONSON: “The Limit of Sensitiveness of the String-galvanometer”. (2d Com- 
munication), p. 613. 
H. C. BURGER: “The Process of Solidification as a Problem of Conduction of Heat”. (Communicated 
by Prof. W. H. JULIUS), p. 616. 
W. STORM VAN LEEUWEN and Miss C. VAN DEN BROEKE: “A Quantitative Inquiry into the Antogonism 
Pilocarpin-Atropin on the Surviving Cat-gut”. (Communicated by Prof. R. MAGNUS), p. 628. 
B. VAN DEX POL Jr.: “Discontinuities in the Magnetisation”. (Communicated by Prof. H. A. LORENTZ), 
p. 637. 
N. H. KOLKMEIJER, J. M. BIJVOET and A. KARSSEN: “Investigation by means of X-rays of the crystal- 
structure of sodium-chlorate and sodium-bromate”. (Communicated by Prof. H. KAMERLINGH 
ONNES), p. 644. : 
H. ZWAARDEMAKER: “On the adsorption of odorous molecules to the surface of solids”, p. 654. 
H. ZWAARDEMAKER and H. ZEEHUISEN: “On Spray-electricity of Solutions of Electrolytes”, p. 658. 
W. KOSTER Dz.: “On the Theory of Hysteresis according to VOLTERRA”. (Communicated by Prof. 
W. H, JULIUS), p. 663. 
Proceedings Royal Acad. Amsterdam. Vol. XXIII. 
