CONTENTS xvii 
PRINS (ADA) and E. H. BücunNer. Vapour pressures in the system: carbon disul- 
phide-methylaleohol. 1232. 
PROPER MOTIONS of the stars, (Determination of the constant of precession and of the 
systematic) by the comparison of KiisTNER’s catalogue of 10663 stars with some 
zone catalogues of the “Astronomische Gesellschaft”. 65. 
Psychology (Experimental). F. Rorrs: “Some further experiments on Inhibition pro- 
ceeding from a false recognition”. 628. 
— F. Roegts: “Intercomparison of some results obtained in the investigation of 
memory by the natural and the experimental learning-method”. 1242. 
PULMONARY RESPIRATION (The movements of the heart and the) with spiders. 162. 
QUADRUPLY infinite system of point groups in space. 1133. 
QUANTITIES 4 and (/a (On the fundamental values of the) for different elements, in 
connection with the periodic system. IL. 2. IIL. 287. IV. 295. 
QUANTITY a (The increase of the) of the equation of state for densities greater than the 
critical density. 359. 
QUANTUM THEORY (On adiabatic changes of a system in connection with the). 576. 
RADIUM as a substitute, in an equiradio-active amount, for potassium in the so-called 
physiological fluids. 633. 
RADIUM-radiation (Distance-relations in the eftects of) on the isolated heart. 1161. 
RADIUS (On the energy and the) of the electron. 985. 
RANA ESCULENTA (The gastrulation of) and of Rana fusca. 906. 
RANA FUSCA RösrL (On the relation of the first three cleavage planes to the principal 
axis in the embryo of). 498. 
REINDERS (w.). The system iron-carbon-oxygen. 175. 
— Birefractive colloidal solutions. 189. 
REINDERS (w.) and L. HAMBURGER, Ultramicroscopic investigation of very thin 
metal and saltfilms obtained by evaporation in high vacuum. 958. 
RHYTHM (Spontaneous and experimental variations of the). 1029. 
ROELS (F.). Some further experiments on Inhibition proceeding from a false 
recognition. 628 
— Intercomparison of some results obtained in the investigation of memory by the 
natural and the experimental learning-method. 1242. 
ROMBURGH (P. VAN) presents a paper of Dr. J.D. JANSEN: “On nitro-derivatives 
of alkyltoluidines and the relation between their molecular refractions and those 
of similar compounds”. 564, 
— presents a paper of Dr. J. D. Jansen: ‘On the distinction between methylated nitro- 
anilines and their nitrosamines by means of refractometric determinations” ([L). 1098. 
RON TGEN-investigation of allotropic forms. 920. 
RONTGENOGRAMS and Röntgenspectra (Interpretation of the) of crystals. 432. 
ROTATION (On the relativity of) in ErnsTe1n’s theory, 527. 
RUTTEN (L.). Modifications of the facies in the tertiary formation of East Kutei 
(Borneo). 728. 
RIJNBERK (G. VAN) presents a paper of Prof. V. WitLEM: “The movements of the 
heart and the pulmonary respiration with spiders”. 162. 
89 
Proceedings Royal Acad. Amsterdam. Vol. XIX. 
