158 PHOSPHORESCENCE IN 



trivirgatus, or Singe Dormeur (Sleeping Monkey), 

 described for the first time by Humboldt, under 

 the name of Simia trivirgata, in his ' Recueil d'Ob- 

 servations de Zoologie et d'Anatomie Comparee ' 

 (vol. i. p. 306). 



I have observed a brilliant scintillation in the 

 eyes of man himself, but only once. The light 

 was of a metallic-pink colour, resembling, in ge- 

 neral aspect, the green light emitted from dogs' 

 eyes. I only saw this in one individual, though 

 I have examined many ; but a friend of mine 

 lately witnessed it in the eyes of a little girl. 

 Both subjects alluded to were remarkably de- 

 licate. 



I do not think we can attribute this light to 

 phosphorescence, but rather, that it is owing to a 

 phenomenon of reflection. I have never had an 

 opportunity of ascertaining whether this luminosity 

 of the eyes of human beings is visible in complete 

 obscurity, as Eennger states was the case with the 

 light emitted from the eyes of Simia trivirgata; 

 but it is certain that the scintillation in the eyes 

 of a cat or a dog is not visible in complete dark- 

 ness. 



In most cases it is not difficult to distinguish 

 light which is reflected from light which is directly 

 transmitted to us from the illuminated body itself, 

 by means of the phenomena to which reflected 

 light gives birth in the polariscope, an ingenious 



