KVA GEO NUL ESN MIES 
ONNES (H. KAMERLINGH) and W. H. Keresom. The specific heat at low tem- 
peratures. IL. 484, III, 1247. 
— and Sopuus WeBeR, Further experiments with liquid helium. O. 493. 
OPTICAL METHOD (An) for determining the ratio between the mean and maximal 
velocities in the turbulent motion of fluids. Contribution to the experiment 
of Frzeau. 1240. 
ORBITAL PLANES (On the) of Jupiter’s Satellites, as derived from measurements made 
at Berlin. 1012. 
Os (CHS. H. VAN). Associated points with respect to a complex of quadrics. 441. 
— On twisted quarties passing through eight associated points. 1147. 
OSMOTIC PRESSURE (Some remarks on the). 184. 
OSTRACODS (Some young-pliocene) of Timor. 1205. 
PADANG (On the post-carboniferous age of granites of the highlands of). 1513. 
Palaeontology. Miss E. C. Fran: “Some young-pliocene Ostracods of Timor.” 1205. 
— W.C. Krein: “On a trilobite fauna of presumably devonian age in the Dutch 
East Indies near Kaloeé (Tamiang district S. E. Atjeh)”. 1632. 
PARALLAX Of the stars (On the influence exercised by the systematic connection between 
the) and their apparent distance from the galactic plane upon the determination 
of the precessional constant and of the systematic proper motions of the stars. 683. 
PASSAGE of light (The) through the slit of a spectroscope. 412. 
passivity (The periodic) of iron. 807. 
PASTEUR’S principle (Investigations on) of the relation between molecular and 
physical dissymmetry. II. 49. 
Pathology. C. Eykman and C. J. C. van Hooerruuyze: “The influence of feeding 
and of starvation on the development of polyneuritis gallinarum.” 1467. 
PEKELHARING (C. A.) presents a paper of Dr. W. E‚ Ringer: “Further researches 
on pure pepsin.” 738. 
— and C. J. C. van Hoocennuyze. Further observations on the relation between 
the muscular tonus and the amount of kreatin in the muscles. 1564. 
PEPSIN (Further researches on pure). 738. 
PERIODIC SYSTEM (Properties of elements and the). 384. 
PERIODICAL SYSTEM (On the additivity of the values of 4 and Va of the equation of 
state and on the fundamental values of these quantities for different elements, 
in connection with the). 1220. 
Petrography. H. A. Brouwer: “Pneumatolytic hornfels from the hill countries of 
Siak (Sumatra)”. 584. 
— H. A. Brouwer: “On the post-carboniferous age of granites of the highlands 
of Padang.” 1513. 
PHOCAENA COMMUNIS (On the vagus and hypoglossus area of). 965. 
PHOSPHORITE (On) of the isle of Ajawi. 214. 
PHOSPHORUS (On tension lines of the system). IV. 106. 
—- (On black). L. 992. 
PHOTOGRAPHIC PLATE (A difference between the «ction of light and of X-rays 
on the). 671. 
