4^6 Dr. F. W. Edridge-Green. The Relation of [June 3, 



Monochromatic Patches in Wave-lengths as Marked out by 

 Trichromics 1, 2, and '6. 



jN-q. of 





Ca: 



6 1. 



Case 2. 



Case 3. 



patches. 



A. 



S\. 



K. 



SA. 



A. 



5a 



1 



7341 

 6160 





1181 



7004 

 6149 



1455 



7004 

 0105 



1499 



2 



6037 

 5877 





160 



6050 

 5877 



173 



0032 

 5877 



155 



3 



6873 

 5677 





196 



5883 

 5694 



189 



5877 

 5765 



112 



4 



5679 

 5408 





271 



5694 

 5453 



241 



5765 

 5600 



105 



5 



5411 

 5309 





102 



5446 

 5166 



280 



5660 

 5529 



131 



6 



5309 

 5178 





131 



5166 

 4991- 



175 



5529 

 5323 



206 



7 



5176 

 5070 





106 



4991 

 4916 



75 



5326 

 5024 



302 



Q 

 O 



5070 

 4969 





101 



4921 

 4855 



66 



5024 

 4855 



169 



9 



4972 

 4806 





160 



4850 

 4713 



137 



4850 

 4713 



137 



10 



4811 

 4019 





703 



4713 

 3853 



860 



4713 

 3853 



860 





Length of spectrum, 

 3322 Angstrom units. 



Length of spectrum, 

 3751 Angstrom units. 



Length of spectrum, 

 3751 Angstrom units. 



8\ represents tlio size of tht- inonodiroinatic jiatcli in Angstrom units. 



On comparing these three cases, it will be noted that there is a series of 

 very remarkable coijicidences. IvT-ch presents 10 monochromatic patches, 

 and in each there are two wide patches at the exti'eniities and one in the 

 ■centre. It will be noticed also that the smaller patches are grouped round 

 this central one. In I and 3 there are in each case five intermediate patches 

 oil oik; side and two on the, other, l)iU, in 1 the live patches arc on the violet 

 side and in .'» on the red side. 



Ah far as these intermediate regions are conceriic<l, ."! looks like a reversal 

 of I. No. 2 has four patches on one side and three on the other. There are 

 also coincidences in the wave-lengths. The lirst two jiatches on the violet 

 side in 2 and 3 are exactly alike in sizi; and ])OKitioii. All three coincide at 



