. CON T EENSTS XXVII 
VOSMAER (G. €. 4). On the occurrence of desmas or desmoids in Hymeniacidon 
sanguinea. 1159. 
VRIES (uk, pe). Circles cutting a plane curve perpendicularly. [. 1449. 
VRIES (JAN DE). A particular bilinear congruence of rational twisted quintics. 39- 
— Bilinear congruences of elliptic and hyperelliptic twisted quintics. 43. 
— Bilinear congruences of twisted curves, which are determined by nets of cubic 
surfaces. 431. 
— presents a paper of Mr. Cus, H. van Os: “Associated points with respect to 
a complex of quadrics”. 441. 
— presents a paper of Mr. Ca. H. van Os: “On twisted quartics passing through 
eight associated points”. 1147. 
— Characteristic numbers for nets of algebraic surfaces. 1270. 
— Tangential curves of a pencil of rational cubies. 1277, 
— A simply infinite system of twisted cubics. 1464. 
— presents a paper of Dr. kK. W. Rurcers: ‘‘On the nature of the limiting surface 
for multiple space transformations”. 1636. 
WAALS (J. D. VAN DER) presents a paper of Prof. A. Smars: “Molecular- 
allotropy and phase-allotropy in organic chemistry”. 346. 
— presents a paper of Prof. A. Sirs: “The apparent contradiction between 
“theory and practice in the crystallisation of allotropic substances from different 
solvents”. 363. 
— presents a paper of Prof. A. Smrrs and Mr. S. C. Bokuorst: “On tension 
lines of the system phosphorus”, IV. 106. 
— presents a paper of Prof. A. Smits: “On critical endpoints in ternary 
systems”. IIL. 793. 
— presents a paper of Prof, A. Sms and Mr. C. A. Lopry pe BRUIJN: “The 
periodic passivity of iron”. 807. 
— presents a paper of Prof. A. Smirs, G. Meyer and R. Pu. Beek: “On black 
phosphorus”. I. 992. 
— presents a paper of Prof. J. D. vaN DER Waats Jr. and Miss AUpA SNETHLAGE : 
“The theory of the Brownian movement”. 1322. 
— presents a paper of Prof. A. Smits: “The P,X-figures of unary systems, 
according to the theory of allotropy”. 1334. 
— presents a paper of Miss A. SNETHLAGE: “On the Brownian movement in 
gases”. 1480. 
— presents a paper of Prof. A. Smits and Dr. A. H. W. Aven: “The application 
of the theory of allotropy to electromotive equilibria”. IV, 1485. 
WAALS Jr. (J. D. YAN DER) and Miss Aupa SNETHLAGE: “The theory of the 
Brownian movement”. 1322. 
WEBER (MAX) presents a paper of Dr. K _Kurper Jr: “Physiology of the 
air-bladder of fishes”. 572. 
WEBER (SOPHUS) and H, KaMERLINGH Onnes. Further experiments with liquid 
helium. O. 493. 
