There are fast and slow polarization effects in organic liquids. For d
ielectric spectroscopy studies, the fast one can be described in frequ
ency domain but the slow one can only be described in time domain. In
differential time domain spectroscopy, each polarization mechanism con
tributes a peak. There are one fast peak and two slow peaks for benzen
e. The slow peaks are related to bound space charges land impurities i
n the liquid. In the melting process of paraffin, the slow peak splits
. Mang important results related to the structure of liquid can be giv
en by time domain method.