INDEX. 



955 



Poole (J. H. J.) on the photo- 

 electric theory of vision, 347 ; 

 on the separation of mercury into 

 its isotopes by centrifuging, 818. 



Porter (Prof. A. W.) on systems 

 with propagated coupling, 432, 

 827. 



Positive rays, on the spectrum of 

 hydrogen, 558, 586. 



Potentials, on the scalar and vector, 

 due to the motion of electric 

 charges, 483. 



Prescott (Dr. J.) on the torsion of 

 closed and open tubes, 569. 



Priestley (Prof. H. J.) on the Ein- 

 stein spectral line effect, 747. 



Prismatic bars, on the transverse 

 vibrations of, 744. 



Propagated coupling, on systems 

 with, 432, 826. 



Quantum theorv of vision, on a, 

 289. 



Radiation, on an electromagnetic 

 theory of, 107 ; on the tem- 

 perature, of gases, 2(57 ; on the 

 supposed weight and ultimate 

 fate of, 549. 



Radium, on the distribution of the 

 active deposit of, in electric fields, 

 357. 



Raman (Prof. C. V.) on the colours 

 of mixed plates, 338, 860. 



Pelativitv, on electronic energy 

 and, 96. 



Resistance, on the effective, of mag- 

 neto windings, 33. 



Rhodopsin, on the liberation of 

 electrons in, 289. 



Pigidity, on the moduli of, for 

 spruce, 848. 



Ring electron, on the properties of 

 the, 113. 



Robinson (J. W. D.) on the Devonian 

 of Ferques, 884. 



Rock-salt, on the intensity of re- 

 flexion of X-rays by, 309. 



Rod, on the period of vibration of a 

 tapering, 259. 



Rontgen rays, on the beta-ray emis- 

 sion from films of elements ex- 

 posed to, 120. 



Rutherford (Sir E.) on the collision 

 of alpha particles with hydrogen 

 atoms, 307 ; on the mass of the 

 long-range particles from thorium 

 O, 570. 



Salia (Dr. M. N.) on the temperature 

 radiation of gases, 267. 



Sargent (H. C.) on the chert forma- 

 tions of Derbyshire, 159. 



Schumann region, on the spectrum 

 of helium in the, 814. 



Sethi (Prof. N. K.) on Talbot's bands 

 and the colour sequence in the 

 spectrum, 211. 



Shafts, on the whirling of, 81. 



Shaxby (J. H.) on vapour pressures 

 and the isothermals of vapours, 

 441. 



Shear, on the correction for, of the 

 differential equation for vibrations 

 of prismatic bars, 744. 



Shenstone (A. G.) on the effect of 

 an electric current on the photo- 

 electric effect, 916. 



Simons (L.) on the beta-ray emis- 

 sion from films of elements ex- 

 posed to Rontgen rays, 120. 



de Sitter's inertial frame, on a hyper- 

 bolic form of, 141. 



Slate (Prof. F.) on electronic 

 energy and relativity, 96 ; on 

 force-transformation, proper time, 

 and Fresnel's coefficient, 652, 



Smith (T.) on the accuracy of the in- 

 ternally focussing telescope, 890. 



Sodium chloride, on the intensity of 

 reflexion of X-rays by, 309. 



Southwell (R. V.) on a graphical 

 method for determining the fre- 

 quencies of lateral vibration, or 

 whirling speeds, for a rod of non- 

 uniform cross-section, 419. 



Sparking voltages in small gaps, on 

 impulsive, 462. 



Spectra, on precision measurements 

 in the X-ray, 675. 



Spectral line effect, on the Einslein, 

 747, 944. 



Spectrum, on Talbot's bands and the 

 colour sequence in the, 211 ; on 

 the, of hydrogen positive rays, 

 558, 566; on the, of helium in the 

 extreme ultra-violet, 814. 



Spruce, on the moduli of rigidity 

 for, 848. 



Stead (G.) on the design of soft 

 thermionic valves, 470. 



Sucrose solutions, cm the activity of 

 water in, 484. 



Surface energy, latent heat, and 

 compressibility, on, 21. 



Swain (Miss L. M.) on the period of 

 vibration of the gravest mode of a 

 thin rod in the form o( a truncated 

 wedge, 259. 



