178 PHOSPHORESCENCE. 



Some papers upon phosphorescence after inso- 

 lation, were afterwards published by M. Dessaignes; 

 they gained the prize of the Academy of Sciences, 

 at Paris, in 1807-1808. This author was the first 

 to observe that substances which are bad conductors 

 of electricity are very easily rendered phospho- 

 rescent, whilst those which are good conductors 

 apparently very rarely or never. 



Dessaignes, moreover, remarked that electricity, 

 either in the shape of an electric spark or dis- 

 charge, or in that of a simple current devoid of 

 light, gives the faculty of shining in the dark to 

 bodies which do not appear to possess it.* Des- 

 saignes was therefore naturally brought to the 

 conclusion that every case of phosphorescence is 

 intimately connected with electricity. 



Some years later, M. Becquerel and M. Biot, 

 in France, and afterwards, Professor Henry, in 

 America, repeating the experiments of Dessaignes, 

 and adding some new ones of their own, arrived 

 at the same conclusion. 



But they were not the only observers who were 

 occupied upon this subject; whilst Grothuss, in 

 Germany, who seems to have been the first to re- 

 cognize the action of an electric discharge upon 

 phosphoric bodies, was evidently remaining be- 



* Grotlmss seems to have been the first to show that the dia- 

 mond became luminous when an electric discharge was passed 

 over it. 



