

PLATE A, Royal Soe. trans. Edin. Vol. XU p. 5 84: 
Weare ne a 







* Projection of observations of the brightness of impressions, with the times during which light acted on the eye . 


























O16 0102 0:0 
Time during which light acted on the eye 
















je iS. ol Ee SS Sa eS AE ee | 
25 0108 01065 0.04 




a eee | 
WEAK. Johnston, Fatt 
