COON “PE NSE S XXV 
PEKELHARING (C. A.) presents a paper of Miss M. A. VAN HERWERDEN: 
_ “Concerning the influence of the adrenal cortex upon the growth and 
the reproduction of lower organisms and its presumable antitoxis 
action.” 1339. 
PHOTOCHEMICAL decomposition (The) of potassium-cobaltioxalate and its 
catalysis by neutral salts. 84. 
PHOTOGRAPHIC PLATE (Extinction by a blackened) as function of wavelength, 
quantity of silver and size of the grains. 848. 
Physics N. H. KOLKMEYER: “Remark on the possible existence of binding 
rings in diamond.” 120. 
— J. Tresuinc: “Derivation of a formula for the temperature dependence 
of the velocity constants in gas reactions from a special image of the 
process.” 143. 
— P. EHRENFEST and V. TRKAL: “Deduction of the dissociation-equilibrium 
from the theory of quanta and a calculation of the chemical constant 
based on this.” 162. 
— H. HursHor: “The osmotic pressure, regarded as a capillary pheno- 
menon. 184. 
— J. J. vAN LAAR: “On the critical quantities of mercury in connection 
with the increase of the molecular attraction on dissociation of the 
double molecules.” I. 267. II. 282. 
— L. HAMBURGER: “On centres of luminescence and variations of the 
gas pressure in spectrum tubes at electrical discharges.” 379. 
— W. H. Jurrius and P. H. van Citrert: “The general relativity theory 
and the solar spectrum.” 522. 
— |. K. A. WERTHEIM SALOMONSON: “The limit of sensitiveness of the 
String-galvanometer.” (2d communication). 613. 
— H. C. Burcer: “The process of solidification as a problem of 
conduction of heat.” 616. 
— B. VAN DER Pou Jr.: “Discontinuities in the magnetisation.” 637. II. 980. 
— N. H. KorkMEYER, J. M. BiyvoET and A. KARSSEN: “Investigation by 
means of x-rays of the crystalstructure of sodium-chlorate and sodium- 
bromate.” 644. 
— W. Koster Dz.: “On the theory of hysteresis according to 
VOLTERRA. 663. . 
— H. C. Burcer: “Observations of the temperature during solidifi- 
cation.” 691. 
— G. Horsr and E. OosreErHuis: “The so-called cyanogen-bands.” 727. 
— A. D. Fokker: “The geodesic precession: a consequence of EINSTEIN’S 
theory of gravitation.” 729. 
— J. M. BurGcers: “On the resistance of fluids and vortex motion.” 774, 
