171 
CHAPTER I. 
HISTORICAL 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 lhght. 
It will thus be seen that phosphorescence per- 
vades the whole of nature. Not only have spon- 
taneous evolutions of ight 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. 
