INORGANIC RESPONSE 



3. Transient rise of current on cessation of light 

 Another very curious fact observed in the retina by 

 Kuline and Steiner is that immediately on the stoppage 

 of light there is sometimes a sudden increase in the 

 retinal current, before the 



usual recovery takes place. 

 This is very well shown in 

 the series of records taken 

 by Waller (fig. 106). It 

 will be noticed that on illu- 

 mination the response-curve 

 rises, that continued illumi- 

 nation produces a decline, 

 and that on the cessation of 

 light there is a transient rise 

 of current. I give here a 

 series of records which will 

 show the remarkable simi- 

 larity between the responses 

 of the cell and retina, in re- 

 spect even of abnormalities 

 so marked as those described 

 (fig. 107). I may mention 

 here that some of these 

 curious effects, that is to 

 say, the preliminary negative 

 twitch and sudden augmen- 

 tation of the current on the cessation of light, have also 

 been noticed by Minchin in photo-electric cells. 



4. Decline and reversal. We have seen that under 

 the continuous action of light, response begins to 



FIG. 107. KESPONSES IN SILVER 

 CELL 



The thick lino represents response 

 during light (half a minute's 

 exposure), and dotted line the 

 recovery during darkness. Note 

 the terminal positive twitch. 



