730 



INDEX. 



Orr (Prof. W. M'=F.) on the impossi- 

 bility of undamped vibrations in 

 an unbounded dielectric, 667. 



Owen (G.) on condensation, nuclei 

 produced in air and hydrogen by 

 heating a platinum wire, 306. 



Oxygen, on the coefficient of expan- 

 sion of, 502. 



Parkinson (J.) on the geology of the 

 Tintagel and Davidstow district, 

 546 ; on primary and secondary 

 devitrification in glassy igneous 

 rocks, 633. 



Patterson (Prof. J.) on the ioniza- 

 tion in air at different tempera- 

 tures and pressures, 231. 



Pender (H.) on the magnetic effect 

 of electric convection, 442. 



Petavel (J. E.) on the effect of 

 pressure upon arc spectra, 569. 



Pjetursson (H.) on a shelly boulder- 

 clay at Burlandshofdi, 639. 



Platinum, on the positive ionization 

 produced by hot, in air, 80, 267 ; 

 on condensation nuclei produced 

 in air and hydrogen by hot, 306. 



Platinum resistance thermometer^ 

 on a new form of, 350. 



Plug experiment, on a modification 

 of the, 518. 



Point-discharge in mixtures of gases, 

 on the, 1 76. 



Poisson's ratio, on the determination 

 of, 417. 



Positive column, on the electric in- 

 tensity in the uniform, 180. 



Potential of a circular current, on 

 the, 19. 



Potentiometer, on the sensitivity of 

 the, for measuring resistances, 38 ; 

 on a direct-reading, for thermo- 

 electric work, 41. 



Preller (Dr. 0. S. DiiRiche) on the 

 age of the principal lake-basins 

 between the Jura and the Alps, 629. 



Prism, minimum deviation through 

 a, 529, 697. 



Przibram (Dr. K.) on the point- 

 discharge in mixtures of gases, 

 176. 



Quadrant electrometer, on the theory 

 of the, 238. 



Quaternions, on a method of estab- 

 lishing the principles of the cal- 

 culus of, 653. 



Radiation, on the pressure of, 157 -, 



on a penetrating, from the earth's 

 surface, 403. 



Radioactive gas from metallic mer- 

 cury, on a, 113. 



Radioactivity of metals, on the, 343 ; 

 on water, 563. 



Radium, on the atomic weight of, 

 64, 098 ; on the loss of negative 

 electricity by, 588. 



Radium radiation and contact elec- 

 tricity, on, 701. 



Raisin (Miss C. A.) on rocks from 

 S. Abyssinia, 545. 



Ramsay (Sir W.) on the vapour- 

 densities of some carbon com- 

 pounds, 492. 



Rayleigh (Lord) on the production 

 and distribution of sound, 289 ; 

 on the work done by forces opera- 

 tive at one or more points of an 

 elastic solid, 385. 



Refraction at a cylindrical surface, on, 

 46 ; on the theory of, in gases, 464. 



Resistance, on the influence of stress 

 and of temperature on the mag- 

 netic change of, in iron, nickel, 

 and nickel-steel, 693. 



Resistances, on the measurement of 

 small, 33. 



Resistance-thermometer, on a new 

 form of platinum, 350. 



Resonance, on the electrical, of metal 

 particles for light- waves, 259. 



Reversals, on photographic, in spec- 

 trum photographs, 577. 



Rheostat, on a simple, 173. 



Richardson (L.) on a section at 

 Cowley, 631 ; on the Rhsetic and 

 Lower Lias of Sedbury Cliff, 636. 



Richardson (0. W.) on the positive 

 ionization produced by hot plati- 

 num in air, 80. 



Righi (Prof. A.) on the influence of 

 magnetic field on thermal conduc- 

 tivity, 725. 



Rontgen rays, on the fluorescence of 

 crystals under, 250. 



Rose-Innes (J.) on the practical 

 attainment of the thermodynamic 

 scale of temperature, 353. 



Runge (Prof. C.) on the relation- 

 ship between spectra and atomic 

 weights, 698. 



Scrivenor (J, B.) on the granite and 

 greisen of Cligga Head, 541 ; on 

 the geology of Patagonia, 542. 



