Spectrograms of the variable star 48 Librae, taken near the last expected minimum, have been examined for irregularities of the shell line profiles. The asymmetries and the core-intensity of the strong shell lines suggest some kind of instability in the shell close to 1964. The harmonic spectral analyses of the acceleration and the radial velocity tabulated functions give an indication of weaker variations superimposed on the 9.6-yr one, which would be responsible for some of the observed peculiarities over the last periods.