The Sense of Sight : Brightness Vision 117 



TABLE 13 



GRAY DISCRIMINATION 



The Delicacy of Brightness Discrimination 



No. 420 



transmitted light, in what is now to be described as the Weber's 

 law apparatus, that I was able to account for the meager power 

 of discrimination which the mice exhibited in the gray tests. 

 As it happened, the Weber's law experiment contributed quite 



