1918.] The Fifth Indian Science Congress. Cxxiil 
inverse effect of the D, and D, lines, thus extending the 
observations of Zeeman and Winawar. 
is remarkable to note the attention the D-lines have 
received from many investigators. Without exaggeration it 
may be said, that D-lines are the best studied of all the 
spectrum lines and most fruitful in their results. 
very slightly inclined to the lines of force and observed the 
: Rae : 
Anomalous Zeeman Effect. 
I have already referred to dissymmetries and shifts noticed 
by various observers. Here I refer to other anomalies of a 
different kind. Paschen and Back showed in 1912, that the 
other in a very peculiar manner. en a sufficiently intense 
magnetic field is applied, a normal triplet is seen instead of 
an expected superposition of the types of separation of the 
oy -~ cause of their abnormal magnetic separation. A 
‘ a % magnetic field may, in the case of close lines, upset the 
ay ibrium and change of type in the single line with the 
“sulting normal separation. 
Voigt has shown how the Lorentz’s theory may be 
con to represent the Zeeman effect of close triplets and 
i: ets uggests the following substitute for Preston's 
ete ‘~The characteristic line systems (simple line, doublets, 
eat I n same series or of similar series have 
Lorentz nd n merically equal parameters he m 
giving the 
Mterval jg 
