SF.XSATIONS IN TERMS OF LUMINOSITY. 271 



Also it was found that 



W 245 390 



100 = 98-32 + 1-68. 

 Therefore 



W RS GS VS 



(7) 100 = 68-42 + 29-90 + 1-68, 



which is the equation to white in terms of RS, GS, and the provisional violet 

 sensation. 



(XVI.) Determination of the Sensation Values in the Orange, Yellow, and Green of 



the Spectrum. 



The slits placed at SSNs 220, 285, and 390. 



220 285 390 W 



48-27 + 50-52 + 1'21 = 100. 



But as will be seen subsequently 



285 RS GS 390 



100 = 4271 + 56-37 + '92. 

 Therefore 



220 RS GS 390 390 W 



48-27 + 21-577 + 28'472 + -465 + 1'21 = 100. 

 Or 



220 RS GS 



(8) 100 = 97-04 + 2-96. 



There is a small residuum of V equal to '01 left, but as it is non-existent at this 

 part of the spectrum it is added to the GS. 



Slits at SSNs 228, 294, and 390. 



228 294 390 



59-80 + 39-86 + '34 = 100. 



294 RS GS 390 



100 = 37-57 + 59-08 + 3'35. 

 From which we get 



228 RS GS 



(9) 100 = 89-37 + 10-63. 



The percentage composition of SSN 236 we have already found as 



236 RS GS 



100 = 80-50 + 19-50. 



