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, im 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 
heht, gives the faculty of shining in the dark to 
bodies which do not appear to possess it.* Des- 
salgnes 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- 
* Grothuss seems to have been the first to show that the dia- 
mond became luminous when an electric discharge was passed 
over it. 
