CO NT ENT 8, XIII 
PLAITPOINT temperatures (On) of the system water-phenol. 594. 
PLANE CURVE (The) of order 4 with 2 or 3 cusps and 0 or 1 nodes as a projection 
of the twisted curve of order 4 and of the Ist species. 627. 
POLAK (J. J.) and A. F. HoLLEMAN. On the bromation of toluol. 511. 
— On the sulfonisation of benzol sulfonic acid. 511. 
POLYHEDRA (On groups of) with diagonal planes derived from polytopes, 277. 
POLYPORANDRA JUNGHUHNII, a hitherto undescribed species of the order of Leacinaceae, 
found in ’s Rijks Herbarium at Leiden. 763. 
POLYTOPES (On groups of polyhedra with diagonal planes derived from). 277. 
POSTMA (o.). On the kinetic derivation of the second law of thermodynamics. 303. 
— On the calculation of the pressure of a gas by the aid of the assumption of a 
canonical ensemble. 781. 
POTERION a boring-sponge. 37. 
PRESSURE of a gas (On the calculation, of the) by the aid of the assumption of a 
canonical ensemble. 781. 
PRINSEN GEERLIGS (H. C.). Rapid change in composition of some tropical fruits 
during their ripening. 74. 
PROBLEM of four bodies (On the periodic solutions of a special case of the). 682. 
— of STEINER (On the combinatory). 352. 
PYILOCODIUM REPENS (On) a new gymnoblastic hydroid epizoie on a pennatulid. 635. 
QUARTERNARY SYSTEMS (Equilibria in). 138. 
REACTION (The dynamic conception of a reversible chemical). 162. 
REEDERS (J. cum.) and Pu. Konnstamm. On the phenomena of condensation for 
mixtures of carbonic acid and urethane in connection with double retrograde 
condensation. 913. 
REFRACTION PHENOMENA (Anomalous) investigated with the spectroheliograph. 213. 
rocks from Central Borneo (The mineralogic and chemical composition of some). 398. 
RUBIACEAE (Lindeniopsis. A new subgenus of the). 123. 
SANDE BAKHUYZEN (E F. VAN DE) presents a paper of Mr. C. SANpERs: 
“Contributions to the determination of geographical positions on the West Coast 
of Africa.” ILI. 88. Appendix. 107. 
— presents a paper of Mr. C. SANDERs: “Observation of the transit of Mercury on 
November 14, 1907 at Chiloango in Portuguese West- Africa.” 108. 
— presents a paper of Mr, J. Weeper: “The investigation of the weights in 
equations according to the principle of the least squares.” 142. 
— presents a paper of Prof. W, pe Srrrer: “On the periodic solutions of a special 
case of the problem of four bodies.” 682. 
SANDERS (C.). Contributions to the determination of geographical positions on the 
West Coast of Africa. [I[. 88. Appendix. 107. 
— Observation of the transit of Mercury on November 14, 1907 at Chiloango in 
Portuguese West-Africa. 108, 
SCHMUTZER (J.). The mineralogic and chemical composition of some rocks from 
Central Borneo, 398, 
