46 



Proceedings of the Royal Irish Aeadetm/. 



III. PtESULTS AND THEIE DISCUSSION. 



Thc7-e arc tvo lines irhich hare 10 comjjonents. 

 Table I. 



\ = 4123-99 



\ = 4205-50 



1 i ^ A 



i 1 -^ ' A 



2 

 2 

 8 

 3 



8 



± 1-69 s 

 ± 1-09 3 

 ± 0-96 p 

 ± 0-50 s 

 ± 0-34 p 



14x.l20g) 

 9 

 8 

 4 



3 ± 2-76 s 

 1 ± 2-14 s 

 1 ± [1-35] s 

 3 + 0-95 p 

 3 ± 0-30 p 



18 X -102/!) 

 14 



9 

 6 

 2 



As the lines are not far apart, the intensities of the components in each 

 line may be considered in comparing. It is seen that although the parallel 

 components are similar in each as regards intensity and separation yet the 

 perpendicular are totally different in both respects. The A-columns show 

 that the intervals are multiples of aliquot parts of a, and that Runge's law 



holds in these cases. For the first line the interval — occurs between each 



of the p- and each of the s- components. Corresponding to this there is in 



the case of the second line the interval -j:^-, but an exception is found with 



the components gi\'ing the separation 1'35. Owing to the weakness of the 

 components, this reading is not very reliable, but re-measiu'ement always gave 

 approximately the same result, and it cannot be that the error is so great 

 that the correct reading is 1"52, which is the reading which might have been 

 expected. Eunge's rule, too, is satisfied by the values obtained, but the Eitz 

 law, though applicable, does not produce the simplification which has been 

 claimed for it. An analysis of the separations of the components of the 

 above two lines gives the following as values of the symbols in the Eitz law. 



A = 4123-99 

 = O-ol ] m = 1, 3 

 = 1-09 \ n = 0, 2 



A = 4205-50 

 to = 0-156 ] m = 2, 6 

 ui' = 1-50 [11 =1, 4, 



"Where some of the whole numbers are wanting in the values for m and 

 n, it is supposed that the components corresponding to them are invisible 



