438 History of Luminescence 



ration as J. J. Berzelius (1843) and R. F. Marchand (1850) had 

 claimed. 



The most important early papers were those of Gottling, Ber- 

 thollet, Spallanzani, and Boeckmann. They will be discussed in 

 some detail, as they illustrate the difficulty in interpreting results, 

 due to impure gases or traces of volatile substances, even water vapor. 



Berthollet was led to study the luminescence of phosphorus after 

 reading about the peculiar results of Gottling (1795) , who found 

 no luminescence in pure oxygen, but claimed luminescence in nitro- 

 gen, and thought the nitrogen acted on the phosphorus. Berthollet 

 was surprised to find that phosphorus did luminesce in nitrogen gas, 

 but the light was weak and did not last long. He was even more 

 surprised to note, as Gottling had claimed, that in pure oxygen at 

 room temperature, no luminescence of phosphorus was visible, but 

 on slight heating light appeared. 



If a bubble of oxygen was allowed to enter the nonluminescent 

 sample of phosphorus in nitrogen gas, the luminescence started again. 

 He consequently suggested that nitrogen decomposed (dissous) the 

 phosphorus, and that only after this change could oxygen attack it, 

 forming white fumes of acid, accompanied by luminescence in the 

 dark. Berthollet also attributed the weak light in " pure " nitrogen 

 to the presence of small amounts of oxygen, as did de Mons (1797) 

 at a later date. 



Spallanzani, like Berthollet, was intrigued with Gottling's observa- 

 tions, and wrote a booklet, Chimico esame degli Esperimenti del 

 Sig. Gottling sopra la Luce del Fosforo di Kunkel Osservata nell'Aria 

 Comune (Modena, 1796) ,^'^ in which, as usual, he came to the cor- 

 rect conclusion. His essential findings were translated in the Annalen 

 der Physik for 1799. Spallanzani studied luminous wood (see Chap- 

 ter XIV) in addition to Kunckel's phosphorus and found that both 

 luminescences became weaker in nitrogen or in marsh gas, and re- 

 turned to the original brightness in air. He therefore concluded 

 that both were the result of a slow combustion, and criticized Gott- 

 ling's conclusions. 



Of special interest is another book, Versuche ilber das Verhalten 

 des Phosphors in verscheidenen Gasarten (Erlangen, 1800) of C. W. 

 Boeckmann, who made a minute comparison of the luminescence of 

 both phosphorus and shining wood in various gases. Boeckmann's 

 results with respect to Kunkel's phosphorus are as follows: ^^ 



"Translated in Ann. der Physik 1: 33-63, 1799. 



^*Frora the translation in Phil. Mag. 16:18-26, 1803. In addition to Gottling's 

 paper the first volume (1795) of Gren's Neues Jour, der Physik contained papers on 

 phosphorus by Lemke and Lampadius and by Hauch. After four volumes, the Journal 

 was continued as Gilbert's Annalen der Physik. 



