171 



CHAPTER I. 

 HISTOEICAL NOTES. 



I HAVE now exposed all the cases of phosphores- 

 cence with which I am acquainted,, in minerals, 

 mineral substances artificially produced, in vege- 

 tables, both phanerogams and cryptogams, and 

 in animals dead or living, besides having alluded 

 to several singular cases of meteorological, and 

 some problematical cases of astronomical, emission 

 of phosphoric light. 



It will thus be seen that phosphorescence per- 

 vades the whole of nature. Not only have spon- 

 taneous evolutions of light been witnessed in our 

 chemical and physical laboratories as curiosities 

 produced by human skill, we find the same in- 

 teresting phenomena exhibited in natural mineral 

 substances, in various plants and animals, where 

 our physical knowledge takes no part in their pro- 

 duction. Moreover, we see phosphoric light de- 

 veloped in the atmosphere, as, for instance, lumi- 

 nous fogs, and in the heavens. 



