CONTLANTS 
CHAPTER XVI 
INORGANIC RESPONSE—EFFECT OF CHEMICAL REAGENTS 

Action of chemical reagents—Action of stimulants on metals—Action 
of depressants on metals—Effect of ‘ poisons ’ on metals—Opposite 
effect of large and small doses 
CHAPTER XVII 
ON THE STIMULUS OF LIGHT AND RETINAL CURRENTS 
Visual impulse : (1) chemical theory; (2) electrical theory—Retinal 
currents—Normal response positive—Inorganic response under 
stimulus of light—Typical experiment on the electrical effect in- 
duced by light 
CHAPTER XVIII 
INORGANIC RESPONSE--INFLUENCE OF VARIOUS CONDI- 
TIONS ON THE RESPONSE TO STIMULUS OF LIGHT 

Effect of temperature—Effect of increasing length of exposure—Rela- 
tion between intensity of light and magnitude of response—A< fter- 
oscillation—Abnormal effects: (1) preliminary negative twitch; 
(2) reversal of response ; (3) transient positive twitch on cessation 
of light ; (4) decline and reversal—Résumé | 
CHAPTER XIX 
VISUAL ANALOGUES 
Effect of light of short duration—A fter-oscillation—Positive and nega- 
tive after-images— Binocular alternation of vision—Period of alter- 
nation modified by physical condition—After-images and their 
revival— Unconscious visual impression 
CHAPTER XX 
GENERAL SURVEY AND CONCLUSION . . 
INDEX 
Xl 
PAGE 
139 
148 
158 
170 
