GONTENTS IX 
H oENEN,S. J. (P. H. J.). Pressure-and temperature- coefficients, volume- and 
heat-effects in bivariant systems. 526. 
— Extension of the law of Braun. 531. 
HOGEWIND/(P.) and H. ZWAARDEMAKER. On Spray-Electricity and Waterfall- 
Electricity. 429. 
HOLLANDER (A. J. DEN) and F. E. vAN HAEFTEN. On the Nitration- 
Products of p.-Dichlor-Benzene. 661. 
HOLLEMAN (A. F.) presents a paper of Dr. A. J. DEN HOLLANDER and Dr. 
F.E. van HAEFTEN: “On the Nitration-Products of p-Dichlor-Benzene.” 661. 
HOMOGENEOUS GROUP (On expansions in series of covariant and contra- 
variant quantities of higher degree under the linear). 251. 
HIJMANS VAN DEN BERGH (A. A.) v. BERGH (A. A. HIJMANS VAN DEN) 
INDEX LOQUELAE (On the). 98. 
INFLUENZA (On the so-called filtrable virus of) described by VON ANGERER. 172. 
INSECTES (Quelques) de |’Aquitanien de Rott, Sept-Monts (Prusse rhénane). 
727. 891. 
INTEGRALS (Remark on Multiple). 150. 
INTERFEROMETER (A Theory of a Method for the Derivation of the 
Distribution of Energy in a Narrow Spectrum Region from the Distri- 
bution of Energy, Observed in an). 200. 
INTESTINE The Action of Atropin on the) depending on its amount of 
Cholin. 438. 
INVOLUTION (On an) among the rays of space. 478. 488. 
— (On an) among the rays of space, which is determined by two 
Reyer congruences. 482. 
— (On an) among the rays of space, which is determined by a bilinear 
congruence of twisted elliptical quartics. 493. 
— (An) of pairs of points and an involution of pairs of rays in space. 580. 
INVOLUTIONS in a field of circles. 379. 
ION CONCENTRATION (A method for the determination of the) in ultra filtrates 
and other protein free solutions. 762. 
ISOTHERMALS of monatomic substances and their binary mixtures. XX. 
Isothermals of neon from + 20° C. to — 217°C. 108. 
JAEGER (F. M.) presents a paper of Prof. H. J. BACKER and J. V. Dussky: 
“On the preparation of a sulphopropionic acid.” 415. 
— On the Symmetry of the R6NTGEN-patterns Obtained by means of 
Systems Composed of Crystalline Lamellae, and on the Structure of 
Pseudo-Symmetrical Crystals. 815. 
Jona (A. W. K. pe). The trimorphism of allocinnamic acid. 497. 
— The Truxillic Acids. 509. 
Juutus (W. H.) presents a paper of Dr. P. H. van Citrert: “The Structure 
of the Sun's Radiation.” 73. 
