xvi Contents 



PAGE 



Charles Francois de C. Dufay 327 



Andreas Siegmund Marggraf 328 



John Canton and Benjamin Wilson 329 



Camillo Galvani 333 



Excitation of Phosphorescence by Spectral Colors . . 333 



Phosphorescence and Electric Sparks 334 



Phosphors and Combustion 337 



The Effect of Ultraviolet and Infrared Rays .... 340 



Dessaignes, Heinrich, and von Grotthus 342 



New Phosphors. The Effect of Traces of Metals . . 345 



Edmond Becquerel and the Recent Period .... 349 



Wave-lengths for Excitation 352 



Duration of Phosphorescence 354 



Intensity of Phosphorescence and the Law of Decay . 356 



Spectrum of Phosphorescence 357 



Temperature Effects 358 



Polarization of Phosphorescent Light 359 



The Photoelectric Effect and Phosphorescence . . 360 

 Theories of Phosphorescence (and Fluorescence) . A 



Review 361 



Chapter IX. Thermoluminescence 366 



Introduction 366 



Seventeenth-Century Observations 366 



Eighteenth-Century Experiments 368 



Relation of Thermoluminescence to Triboluminescence 370 



Nineteenth-Century Contributions 371 



Candoluminescence 377 



Chapter X. Triboluminescence, Piezoluminescence, Crys- 



talloluminescence, and Lyoluminescence .... 378 



Introduction 378 



Triboluminescence and Piezoluminescence .... 379 



Early Observations 379 



Relation to Electricity 381 



Eighteenth-Century Observations on Minerals . . 382 



Nineteenth-Century Research 385 



Crystalloluminescence 387 



Lyoluminescence 389 



