Discussion Considerable difficulty was encountered in locating the Raman frequencies v2 and v4 in the case of lead tetrachloride since they lay close to the exciting line and were obscured by the background from it. Plate tracings showed a peak at 90 cm.-l, but on only one plate were two separate lines resolved, these appearing at 85 cm.-'and 93 cm.-l. The latter values are inclosed in brackets in Table I. The frequencies obtained for lead ...
