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102 "HI. THEORY OF THE ZEEHAN-EFFJECT.

spending to the circular motion of the electron. The formulae (160)
show that, for an observer placed on the positive axis of 0, the
rotation of the electron takes place in the same direction as that of
the hands of a clock. From this it may be inferred that the rays
emitted along the positive axis by the motion (160) have a right-
handed circular polarization.

Similar considerations apply to the motion represented by (161).
The radiation issuing from it in the direction just atated has a left-
handed circular polarization. If it is further taken into account that
the frequency of the rays is in every joase equal to that of the motion
originating them, one can draw the following conclusions, which have
.been fully verified by Zeeman's experiments.¹)

Let the source of light be placed in a magnetic field whose
lines of force are horizontal, and let the light emitted in a horizontal
direction at right angles to the lines of force be examined by means
of a spectroscope or a grating. Then we shall see a triplet of lines,
whose middle component occupies the place of the original line,
Each component is produced by plane polarized light, the electric
vibrations being horizontal for the middle line, and vertical for the
two outer ones.

If, however, by using an electromagnet, Ojae coi'e of which has
a suitable axial hole, we examine the light that is radiated along the
lines of force, we shall observe only a doublet, corresponding in po-
sition to the outer lines of the triplet. Its components are both
produced by circularly polarized light, the polarisation being right-
handed for one, and left-handed for the other.

81, After having verified all this, Zeemaa was able to obtain
two very remarkable results. In the first plat?e, it was found that,
for light emitted in a direction coinciding with that of the magnetic
force, i. e., if H, is positive, in that of OZ, the polarisation of the
component of the doublet for which the frequency is lowestj is right-
handed This proves that, for a positive value of H,, the first of
the two frequencies given by (164) is the smaller, Therefore, the
charge e of the electron to whose motion the radiation, has been
ascribed must be negative. This agrees with the general result of
other lines of research, that the negative charges have & greater mo-
bility than the positive ones,

The other result relates to the ratio between the numerical values
of the electric charge and the mass of the movable electrons. This
ratio can be calculated by means of the formula© (164), as sooa as
the distance between the components, from which we can deduce

1) Note 48.



	102 "HI. THEORY OF THE ZEEHAN-EFFJECT. spending to the circular motion of the electron. The formulae (160) show that, for an observer placed on the positive axis of 0, the rotation of the electron takes place in the same direction as that of the hands of a clock. From this it may be inferred that the rays emitted along the positive axis by the motion (160) have a right- handed circular polarization. Similar considerations apply to the motion represented by (161). The radiation issuing from it in the direction just atated has a left- handed circular polarization. If it is further taken into account that the frequency of the rays is in every joase equal to that of the motion originating them, one can draw the following conclusions, which have .been fully verified by Zeeman's experiments.¹) Let the source of light be placed in a magnetic field whose lines of force are horizontal, and let the light emitted in a horizontal direction at right angles to the lines of force be examined by means of a spectroscope or a grating. Then we shall see a triplet of lines, whose middle component occupies the place of the original line, Each component is produced by plane polarized light, the electric vibrations being horizontal for the middle line, and vertical for the two outer ones. If, however, by using an electromagnet, Ojae coi'e of which has a suitable axial hole, we examine the light that is radiated along the lines of force, we shall observe only a doublet, corresponding in po- sition to the outer lines of the triplet. Its components are both produced by circularly polarized light, the polarisation being right- handed for one, and left-handed for the other. 81, After having verified all this, Zeemaa was able to obtain two very remarkable results. In the first plat?e, it was found that, for light emitted in a direction coinciding with that of the magnetic force, i. e., if H, is positive, in that of OZ, the polarisation of the component of the doublet for which the frequency is lowestj is right- handed This proves that, for a positive value of H,, the first of the two frequencies given by (164) is the smaller, Therefore, the charge e of the electron to whose motion the radiation, has been ascribed must be negative. This agrees with the general result of other lines of research, that the negative charges have & greater mo- bility than the positive ones, The other result relates to the ratio between the numerical values of the electric charge and the mass of the movable electrons. This ratio can be calculated by means of the formula© (164), as sooa as the distance between the components, from which we can deduce 1) Note 48.