276 



Sir James Dewar 



[Jan. 16, 



Corrected for reflection. 



Common Substances 

 Glass 



Mica, white 



,, black 



Celluloid 



Collodion films ... 



Gelatin ' , 



,, 2 discs ... 

 3 „ 

 Goldbeater's skin 

 Ebonite 



India-rubber 



f By reflected light. 



