196 
CHAP TH, TE. 
PRACTICAL CONSIDERATIONS. 
To those reflective minds who really enjoy the beau- 
ties of nature and contemplate them with admira- 
tion, practical details are of so little interest, that 
I had not the intention of saying anything upon 
the subject in this work. But, as some persons 
endeavour, at any risk, to turn everything to pro- 
fit, to make everything in nature useful to man 
in one way or another, [ am willing to show that 
phosphorescence is far from being devoid of uti- 
lity, and that it has already been extensively ap- 
plied to various uses, often without a knowledge 
of the fact. 
lt would, indeed, be superfluous here to dilate 
upon the uses of light ; 1t will be sufficient for me 
to state that the most powerful hght ever pro- 
duced by man, without exception, is owed to a 
phenomenon of phosphorescence. I allude to the 
“ Drummond, or Lime-light.” 
It is produced by submitting lime, a highly 
