This collection of 48 publications is divided into four groups which may be labelled 1. Original papers on the vibrational spectra of aromatic systems. These comprise A1 to A25. 2. Studies of em pirical inter-nuclear potential functions B1-6. 3. Vibrational analyses &s an aid to structural analysis 01-14. 4. Instrum entation and techniques DI-3. 1. As is seen from the distribution of papers amongst the groups, most effort has been devoted to a study of aromatic systems, primarily of fluoro-arom atics. The latter offer special unique and advantageous properties for vibrational studies. The objectives of this work and the extent to which they have so far been realised may be summarised as follows. (i) - the establishing of the pattern of fundamental vibrational frequencies. Much effort has been devoted to showing that the assign ments for the various molecular species are consistent with one another. (a6, as, A9, A1 9, A22 etc.). In this context three extremely useful and general rules have been established (A2, A9, A22). All are strictly applicable only to isotopically related systems but have been shown to be remarkably well upheld when the systems compared differ by non isotopic substitution. The ’Inequality Rule’ was first proposed by the writer and D.H. Whiffen (A2). The second rule, the ’Sum Fule’, is a well established rule for isotopic systems, but has been shown (A9) to be very useful outside of its normal realm of applicability as a consequence of linear gradation of bond properties with isotopic substitution. An adaption of the 'Eedlich-Teller Product Rule’ has also been usefully employed in deciding between alternative proposed assignments (A22).