INORGANIC RESPONSE 



161 



the incandescent burner is at a distance of 150 cm., has 

 been taken as the arbitrary unit. In order to make 

 allowance for the possible effects of fatigue I took two 



r\ 



r\ 



r 



FIG. 103. RESPONSES OF SENSITIVE CELL TO VARIOUS INTENSITIES OF LIGHT 



On the left the responses are for diminishing intensities in the ratios of 7, 5, 3, 

 and 1. On the right they are for the increasing intensities 1, 3, 5, and 7. 

 The thick lines are records during exposures of one minute ; the dotted 

 lines represent recoveries for one minute. 



successive series of responses (fig. 103). In the first, 

 records were taken with intensities diminishing from 

 7 to 1, and immediately afterwards increasing from 1 to 

 7, in the second. 



TABLE GIVING KESPONSE TO VAJRYING INTENSITIES OF LIGHT 



(The intensity of an incandescent gas-burner at a distance of 150 cm. 

 is taken as unit.) 



As the zero point was slightly shifted during the 



M 



