Chemiluminescence 453 



(1803) also mentioned the whitish light when lime and the reddish 

 light when magnesia are mixed with strong acids like H2SO4 and 

 HCl. After the discovery of hydrogen peroxide it was noticed that 

 its decomposition in the presence of catalysts like colloidal silver 

 and platinum, PbOz and MnOz will result in light production. 



In 1861 K. J. von Reichenbach gathered together many instances 

 of dim chemiluminescence which he held were the result of vibra- 

 tion of molecules during such processes as crystallization, fusion, 

 solidification, effervescence, and condensation of vapors. He men- 

 tioned the light which appears when H2SO4 is added to water, or 

 HCl to calcite, when water drops pass into steam or water is elec- 

 trolysed, and other remarkable phenomena, so unusual in fact that 

 many of his claims may have been based on unknown impurities, or 

 may have been subjective phenomena.*^ 



ORGANIC COMPOUNDS 



The first important study of organic chemiluminescences in solu- 

 tion is due to Bronislaus Radziszewski (born 1838) , professor of 

 chemistry at Lemberg in Galicia. He published two papers in 1877, 

 one dealing with the luminescence which appears when lophin, 

 amarin, or hydrobenzamid are shaken with air in alkaline alcohol 

 solution, the other, a few months later, describing the light of new 

 organic compounds, aldehydes and amides, treated in the same way. 

 These contributions were followed (1880) by investigation of a long 

 list of organic and biological compounds, terpene oils, cholic acids, 

 fatty acids, etc., which luminesced when oxidized in alkaline solu- 

 tion. The first chemiluminescent spectrum of an organic compound 

 in solution, that of lophin, was also studied by Radziszewski (1880) 

 and found to have a short continuous band, brightest at the Fraun- 

 hofer line E, quite similar to the spectra of some luminous animals. 



Radziszewski's observations on oils and his spectral studies led 

 him in 1883 to extract a yellowish oil from the luminous jellyfish, 

 Pelagia noctiluca, which luminesced, " blitzartig," on shaking with 

 alkali, just as does the living jellyfish itself, and he held that oxida- 

 tion of an oil was responsible for the light. Although the idea that 

 the luminescence of animals was due to an oil was expressed by 

 Phipson in 1860 and 1862 and by Panceri in 1871, Radziszewski's 

 studies on luminescent oils greatly influenced the later ideas on the 

 chemical nature of the luminous material of luminous animals. 

 They were reviewed by a Dr. Kolbert in the Deutsche Medezinische 



*^ Among other subjects, Reichenbach wrote on Od, a hypothetical force which he 

 thought explained mesmerism and animal magnetism. 



