SENSATIONS IN TERMS OF LUMINOSITY. 



The adopted reading was 



V BB 



(33) 100 = 72-5 + 27-5. 



-'7J 



(XIX.) Collected Colour Sensations. 

 TABLE I. 



This equation was applied to the foregoing percentages of violet in the different 

 colours. The next table shows the provisional and the correct percentages. 

 1 n this and the following tables the former are shown in italics. 



Both sets of ordinates were drawn from the preceding table, and freehand curves 

 drawn through them. (The standard scale is the same as in ' Colour Photometry,' 

 Part III.) The results are shown in fig. 3. It will be noticed that, had the 

 provisionally-employed violet sensation been correct, the percentage curves are very 

 fairly regular, and altogether what would have been expected, but that in the true 

 sensation curves the red sensation takes a form which is curious, and> one which, 

 from any theoretical considerations, would not be prophesied as probable. In every 

 investigation, whether of colour fields or otherwise, the red sensation seems to be but 

 little connected with the other two. 



2 N 2 



