^in,^Ji '-u.i RiLjuniiu^ ^J lh^~fho -- 



V 



f ■ Lii / 



Fig. 35. A plate of the luminescent eflects of phosphorus from the book of J. S. 

 Elscholtz, Be Phosphoris Observationis (Rerlin. 1081). Elsciioltz described four 

 phosphors (Berlin, 1676) , the Bolonian. the BaUlewinian. tlie true phospiiorus 

 fulgurans or stellatus (also called " ignis frigidus ") and a iliermophosphorus which 

 would glow when warmed slighth. 



