568 



CAPTAIN ABNEY AND MAJOB-QBNEBA.L TESTING 



A certain amount of white light being reflected from the coloured surface, a cor- 

 rection is necessary for this, and the last column was derived from the preceding one 

 by deducting 22 (the amount of white light present) and multiplying by T81. 



XLIII. Intensity Curves of Coloured Pigments. 



Figs. 29 (Plate 22) and 30, 31, 32 (Plate 23) give the curves of some of the many 

 colours which have been measured by the method described in this paper. These 

 curves are plotted to the normal scale of wave-lengths, and the following tables 

 give the readings at the different wave-lengths. 



