L891.] 



Colour of Cases of Tobacco Scotoma, 



505 



She matched the red disc alone with black and white, aud also the 

 }lue disc alone 



360 E = 56 W+304 B (corrected), 

 360 U = 60 W + 300 B (corrected). 



any proportion of B and U mixed together she matched a grey 

 approximately the same intensity as above, as it might be supposed 

 she would from the last two equations. 



The thin line curve is the curve of luminosity for the normal eye. 



