GON WEN TDS VII 
Patus (An interference phenomenon due to the introduction of sodium 
vapour into one of the) of the FizEAUu-MICHELSON interferometer- 
arrangement. 206. 
PEKELHARING (GC. A). On the movement of pepsin in a protein- 
containing or protein-free gel of agar-agar. 269. 
PELLIA EPIPHYLLA (Concerning the influence of light and. gravitation on). 2. 
PENCILS (Explanation of some interference-curves of uni-axial and bi-axial 
crystals by superposition of elliptic). (Second paper). 195. 
PePsiN (On the movement of) in a protein-containing or protein-free gel of 
agar-agar. 269. bh 
PHOTOTROPIC curvatures (On anti-) occurring in the coleoptiles of Avena. 177. 
Physics. H. Groot: "Gravity and pressure of radiation”. 64. 
— C. A. Reeser and R. SissincH:’’An extension of the theory of BABINET's 
compensator’. 102. 
— C. A. REESER and R. SiIssINGH: "The optical investigation of surface 
layers on mercury and a more refined method of observation with 
BABINET’S compensator’. 108. 
— W. H. KeesoMm: "On the calculation of the molecular quadrupole- 
moments from the equation of state’. 162. 
— G. C. Dissetz Jr. and P. ZEEMAN: “An interference phenomenon due 
to the introduction of sodium vapour into one of the paths of the 
FizEAU-MICHELSON interferometer-arrangement’’. 206. 
— F. ZERNIKE: “A moving coil galvanometer of high sensitivity”. 239. 
— J. J. van LAAR: "On the equation of state for arbitrary temperatures 
and volumes. III. On the law of force between the molecules of mon- 
atomic substances”. 294. 
— H. A. Lorentz: “Double refraction by regular crystals’. 333. 
Physiology. Miss L. Kaiser: ’Muscle sound in birds”. 78. 
— Miss L. Kaiser: "A simple method to obtain a curve of the contrac- 
tion of the M. arrectores pilorum’’. 81. 
— JASPER TEN CATE: “Regarding automatic movements of the isolated 
iris.” 84, 
— S. pe Boer: “On the action of the novocain on the tonus of the 
skeletal muscle.” 185. 
— K. LANDSTEINER: “On the formation of heterogenetic antigen by 
combination of hapten and protein.’ 237. 
— H. ZWAARDEMAKER: “On superficial and internal processes.” 246. 
— C. A. PEKELHARING: “On the movement of pepsin in a protein-con- 
taining or protein-free gel of agar-agar.” 269. 
— L. J. J. Muskens: “The myoclonic reflexes.” 280. 
