The electron, its isolation and measurement and the determination of some of its properties

by Robert Andrews Millikan

series, which is produced by stimulating the inmost pair of electrons in each atom, and the

series, which is produced by stimulating the group of eight electrons in the second ring or shell from the center.

Fig. 21b—PHOTOGRAPHS OF THE SPECTRA OF THE CHARACTERISTIC X-RAYS FROM CERTAIN SUBSTANCES

The two

lines are here close to the central image, for the