220 History of Luminescence 



discharge tubes, beginning in 1878. He then became interested in 

 phosphorescence and other types of inorganic luminescence which 

 took up a major part of his research time, but his only book on 

 physics, a Physikalische Practicum with H. Ebert (4th ed., 1899), 

 hardly mentions luminescence. An early student of the history of 

 science, Wiedemann specialized in Arab knowledge, concerning 

 which he published many papers, and a booklet, Die Naturwissen- 

 schajten bei den Araben (Hamburg, 1890, 32 pp.) • 



BOOKS ON INORGANIC LUMINESCENCE 



After Heinrich's compilation in 1811-1820, Die Phosphorescenz 

 der Korper, most of the papers on luminescence were published in 

 various journals. One little known thesis, De Phosphorescentia per 

 Irradiationem, designated a " Dissertatio Historica Physica " by 

 Petrus Adrianus Bergsma, appeared in Dutch at Utrecht in 1854. 

 As the title indicates, the essay was a comprehensive historical 

 account of phosphors. There were three sections: (1) From dis- 

 covery of the Bolognian phosphor in 1604 until the work of Bec- 

 caria in 1771; (2) From Beccaria to Becquerel, 1771-1839; (3) 

 From Becquerel until 1854. Thus the history ended in the midst 

 of the great labors of Edmond Becquerel, even before his descrip- 

 tion of the famous phosphoroscope, but the divisions of the book 

 indicate the influence which E. Becquerel's work was exerting 

 throughout Europe at this time. 



Another work of interest on a special subject was Die Fluorescenz 

 des Lichtes of 115 pages, published at Vienna by F. J. Pisco in 1861. 

 The volume was based on Stokes' research and covered quite com- 

 pletely the facts concerning fluorescence known at the time (see 

 Chapter XI) . 



The only other book on luminescences which appeared during 

 the Becquerel period was Phosphorescence , by T. L. Phipson, pub- 

 lished in London (1862) . This semi-popular account used the word 

 " phosphorescence " in a broad sense, to include all kinds of light 

 emission at a low temperature. Somewhat less space is devoted in 

 Part I to " Phosphorescence of Minerals " than to " Phosphorescence 

 of Vegetables " (Part II) or " Phosphorescence of Animals " (Part 

 III) , but every aspect of inorganic luminescence knowledge is in- 

 cluded—light after insolation; light by heat, cleavage, friction, per- 

 cussion, crystallization, and molecular or chemical change; also 

 " phosphorescences of gases," " metereological phosphorescence," 

 and " invisible phosphorescence." By the latter, Phipson referred 

 to " some curious phenomena discovered by my ingenious friend M. 

 Niepce de St. Victor." The effect was the rapid formation of a 



