819 ] 



INDEX to VOL. XXX. 



Aberrations of a symmetri- 

 cal optical instrument, on the 

 third-order, 270. 



Air, on the residual ionization in, 

 enclosed in a vessel of ice, 428 ; 

 on the mobilities of ions in, at 

 high pressures, 484. 



Alpha particles, on the passage of, 

 through hydrogen, 240; on the 

 velocities of the, from thorium 

 active deposit, 702. 



rays, on the delta radiation 



emitted by zinc when bombarded 

 by, 491 ; on the ionization tracks 

 of, in hydrogen, 676. 



Anderson (E. M.) on the pitchstones 

 of Mull, 447. 



Arc and spark spectra of nickel, on 

 the, 885. 



Ash worth (Dr. J. R.) on the appli- 

 cation of van der Waals' equation 

 of state to magnetism, 711. 



Atmospheric precipitation, on the 

 electricity of, 1. 



Atoms, on the quantum theory of 

 radiation and the structure of, 

 394 ; on the construction of com- 

 pound molecules with theoretical, 

 618 ; on energy relations involved 

 in the formation of complex, 

 723. 



Baly (Prof. E. C. C.) on light 

 absorption and fluorescence, 510. 



Barkla (Prof. C. G.) on the velocity 

 of electrons expelled by X rays, 

 74.',. 



Barnes (Prof. J.) on the maximum 

 frequency of the X rays from a 

 Coolidge tube for different volt- 

 ages, 839 ; on the efficiency of pro- 

 duction of X rays from a Coolidge 

 tube, 361 ; on the high-frequency 

 spectrum of tungsten, 368. 



Benzene ri ng, on a structural formula 

 for the, 674. 



Beta particles, on the decrease in 

 velocity of, in passing through 

 matter. 627. 



rays, on the excitation of gamma 



rays Dy, 220. 



Bohr (Dr. N.) on the quantum theory 

 of radiation and the structure of 

 the atom, 394 ; on the decrease of 

 velocity of swiftly moving elec- 

 ted particles in passing through 

 matter, 581. 



Books, new : — Knott's Physics, 208 ; 

 Allen's Photoelectricity, 208 ; 

 Calculus Made Easy, 445 ; Nunn's 

 The Teaching of Algebra, and 

 Exercises in Algebra, 818. 



Bragg (Prof. W. H.) on the structure 

 of the spinel group of crystals, 805. 



Brown (W. Or.) on reflexion from a 

 moving mirror, 282. 



Burton (Dr. C V. ) on the scattering 

 and regular reflexion of light by 

 gas molecules, 87. 



Cadmium vapour, on the absorption 

 spectrum of, 695. 



Candle-power, on the unit of, in 

 white light, 63. 



Carbon, on the construction of com- 

 pound molecules of the organic 

 compounds of, 613. 



atoms, on the construction of 



the diamond with theoretical, 

 257. 



dioxide, on the dispersion of, 



in the infra-red region of the 

 spectrum, 737. 



Chakravarti (S. K.) on the tempe- 

 rature coefficient of Young's 

 modulus for electrically heated 

 iron wire, 373. 



Colour identity, on the estimation 

 of high temperatures by the 

 method of, 34. 



Coolidge tube, on the X rays from 

 a, 339, 361. 



Corresponding states, on the general 

 theory of, 146. 



Crehore (Dr. A. C.) on the con- 

 struction of the diamond with 

 theoretical carbon atoms, 257 ; on 

 the construction of compound 

 molecules with theoretical atoms, 

 613. 



Crystals, on the structure of the 

 spinel group of, 305. 



