40 B. E. Moore 
and one osmium line, or total of twenty-three lines. There are 
some duplicates, which leaves eighteen types, including neon, and 
these are all different from the type of Hg line 2655. ‘The inter- 
val a/5 is well represented in the first subordinate series satellite 
of Cu, Ag, Al, and TI, but the interval does not enter in right. pro- 
portions in yttrium or zircon to form the same types. Some types 
have the same factors as others with one or more factors sup- 
pressed. The question naturally arises, whether these lines may 
not be duplicates and whether the omission might not have arisen 
from weakness of the component or inadequate exposure. This 
may be true in a few cases, but generally it is not for the follow- 
ing reason. The ratio of the intensity of components is known 
both in the line having all the components and in the line having 
some components hypothetically missing. A simple mental calcu- 
lation will then tell whether the missing component, if existing at 
all, may have been too weak to leave a photographic impression 
on the plate. 
IX. CONCLUSIONS 
1. The lines of the triplet class in barium mostly fall into groups 
with a separation similar to the separation of some components 
of lines other than triplets. 
2. A great majority of all lines, having more than three com- 
ponents, possess underlying simplicity and likeness in the great 
variety of their separations. This simplicity or similarity 1s mani- 
fested in small magnitudes which are designated by the term “‘in- 
tervals.” The components of these lines are obtained by multi- 
plying the intervals by ‘‘factors.” The intervals themselves may 
have multiples. The smallest intervals are aliquot parts of a, 
(where a is the separation of the “normal triplet’ as given hy 
Professor Runge). The latter recently found in neon, the aliquot 
intervals a/2, a/3, a/4, a/5, a/6, a/7,a/11,a/12. Allexcept a/12 
are observed in the present experiment. 
3. The great variety in the magnetic separations arises prin- 
cipally from the variation both in number and in magnitude of the 
interval factors. The product of interval and factor or combina- 
tion of factors gives the tvpes of separation. 
AO 
