The Nineteenth Century 215 



connection with the wave theory of light and most useful because of 

 its bibliography. Another was the Elements of Natural or Experi- 

 mental Philosophy (2 v., Philadelphia, 1813) , by Tiberius Cavallo 

 (1749-1809) , best known for his work on electricity. The book 

 contains a section dealing with " Phosphorescent Bodies," which 

 are divided into five types: (1) Animals like glowworms; (2) Phos- 

 phors which imbibe light and give it off in the dark; (3) Bodies 

 which light when heated slightly; (4) Bodies which light as a result 

 of attrition; (5) Bodies in a state of decomposition such as fish and 

 flesh, also the ignis fatuus. 



In the middle of the century, in the various textbooks of the 

 Becquerels, father and son, particular attention was paid to lumi- 

 nescence. These texts exerted such an influence on subsequent study 

 that they will be considered in a special section. 



The Coiirs de Physique (1856) of Adolphe Ganot, famous as a 

 college textbook in the English translation (1861, 1876) of E. 

 Atkinson, mentioned luminous wood, flesh, and the sea, without 

 much detail. 



Bioluminescence was included as late as 1879 in the Traite Ele- 

 mentaire de Physique Theoretique et Experimental (4 v., Paris) of 

 P. A. Daguin, which devoted five pages to phosphorescence of ani- 

 mals and inorganic substances, and mentioned the bacteria of Nuesch 

 (1877) as the cause of phosphorescence of meat. 



An important physics text, Cours de Physique, by J. E. Jamin, 

 appeared as a first edition (3 v.) in 1858-1866 and was used in the 

 £cole Polytechnique, Paris for many years. The third edition (of 

 four volumes, 1878-1883) with the name of E. M. L. Bouty added 

 as co-author, contained one of the best accounts of phosphorescence 

 and fluorescence to appear at that time. The thirty-page treatment 

 included all the pertinent facts concerning emission spectra, color 

 changes in the phosphorescence depending on temperature or type 

 of impurity, duration of the phosphorescence, etc. In addition it 

 was well illustrated with graphs and figures. 



The end of the century is noted not only for great increase in 

 volume of journal papers, but for the massive German compilations 

 on physics, which were to run to many volumes in the twentieth cen- 

 tury. One of these, which appeared in several editions was the Lehr- 

 buch der Experimental Physik of Adolf Wiillner (1835-1908) , who 

 carried out important research on fluorescence. The first edition 

 was published in 1870 and contained little on luminescence, but the 

 fourth edition in 1883 devoted considerable space to the subject, 

 and the fifth edition (vol. 4) , appearing in 1899, contains sixty- 

 three pages on electroluminescence, fluorescence, and phosphores- 



