ClO) Ne TENs Es: Vv 
Chemistry. KE. H. BücnNer and Apa Prins: “Vapour pressures in the system: carbon 
disulphide-methylalcohol”, 1232. 
CIRCLES (The) that cut a plane curve perpendicularly. IL. 255. 
CLARK (A, L.) and J. P. Kurnen, Critical point, critical phenomena and a few con- 
densation-constants of air. 1088. 
CLEAVAGE PLANEs (On the relation on the first three) to the principal axes in the 
embryo of Rana fusca Rösel. 498, 
cLoups (On the influence of an electric field on the light transmitted and dispersed 
by). 415. 
COHEN (ERNST) presents a paper of Prof. H. R. Kruyr and W. D. HELDERMAN: 
“The equilibrium solid-liquid-gas in binary systems which present mixed erystals”’, 
439. 
Jen presents a paper of Prof. H. R. Kruyr: ‘The equilibrium solid-liquid-gas in 
binary systems which present mixed crystals”. 4th Comm. 555. 
— presents a paper of Dr J. Our Jr. and A. J. Byu: “RÖNTGEN-investigation of 
altotropic forms”. 920. 
— presents a paper of Prof. H. R. Kruyr: “Current potentials of electrolyte 
solutions.” 2nd Communication. 1021. 
COLLOIDAL SOLUTIONS (Birefractive). 189. 
COLOURPATTERN (The) on Diptera-wings. 1141. 
CONDENSATION-CONSTANTS (Critical point, critical phenomena and a few) of air. 1088, 
CONSTANT of precession (Determination of the) and of the systematic proper motions 
of the stars, by the comparison of KustNEr’s Catalogue of 10663 stars with 
some zone-catalogues of the “Astronomische Gesellschaft”. 65. 
CONTINUA (Einstein's theory of gravitation and Hereiotz’s mechanics of). 884. 
CORAL REEF problem and isostasy. 610. 
CORPUT (J. G. VAN DER). On the values which the function Z (s) assumes for s 
positive and odd. 489. 
— On an arithmetical function connected with the decomposition of the positive 
integers into prime factors. 1. 826. II. 842. 
CRANIUM (On the determination of the position of the macula planes and the planes 
of the semicircular canals in the). 49. 
CRITICAL DENsITY (The increase of the quantity a of the equation of state for densities 
greater than the). 359. 
CRITICAL POINT (The clustering tendency of the molecules at the). 1321. 
— Critical phenomena and a few condensation-constants of air. 1088. 
CROMMELIN (Cc. A), H. KAMERLINGH ONNES and P. G. Cara. [sothermals of 
monatomic substances and their binary mixtures. XVII, 1058. 
CRYOGENIC LABORATORY (Methods and apparatus used in the). XVII. 1049. 
CRYSTALS (Interpretation of the Röntgenograms and Röntgenspectra of). 432. 
— (Lhe equilibrium solid-liquid-gas in binary systems which present mixed). 3rd 
Comm. 439. 4th Comm. 555. 
— (Contributions to the research of liquid). 1315. 
CUBIC SURFACE (Pencils of twisted cubics on aj. 97. 
