390 
DR. W. M. HICKS: A CRITICAL STUDY OF SPECTRAL SERIES. 
The evidence given in the preceding pages would seem to establish conclusively the 
existence of these links and linkages in the spark spectra at least of Ag and Au. Of 
740 lines in Au only 41 have no p, s, 1000, or 14333 links attached to them, whilst 
100 others with links have not been allocated to the linkages exhibited in the maps. 
It is noticeable also that of these 100, the majority show the 1000 and 14333 links, 
indicating that they have relations to diffuse sequences—not here discussed. Of 600 
lines in Ag only 92 show none of the p or 5 links, of which 54 occur in the first 60 and 
last 30, where the fainter lines which might complete links are not observed through 
photographic and instrumental difficulties. In addition, about 110 are not allocated 
to definite linkages in the maps. We should expect many of these—from analogy 
with Au—to have reference mainly to linkages related to diffuse sequences. 
The complete problem of the relations involved and criteria for true and spurious 
links, is one involving a much more exhaustive treatment than that given in the 
present communication. It will necessitate the consideration of the D sequence links, 
and especially of lateral displacements, the existence of which the present discussion 
has clearly indicated. The cause of the variations in the magnitude of the links 
themselves must be discovered and will require a more accurate determination of wave¬ 
lengths and of possible observation errors. These questions are reserved. 
