The Physical Chemistry Laboratory was built in 1941 and at that time also housed the inorganic chemistry laboratory. It replaced the Balliol-Trinity Laboratories. The east wing of the building was completed in 1959 and inorganic chemistry, already in its own building on South Parks Road, then became a separate department in 1961. In 1972, the Department of Theoretical Chemistry was established in a house on South Parks Road, and in 1994, the amalgamation of the physical and theoretical chemistry departments took place. This was followed shortly by the theoretical group moving into the PTCL annexe in 1995. The PCL in 1942 from a photograph by J.R.H. Weaver As part of the 50th Anniversary of the PTCL in 1991 a book was produced detailing the history of the laboratory. The contents of these pages is based on that book. In the first section are some facts, figures and so on from published reports and members of the laboratory collated by Richard Barrow, whilst the second part is a personal account by John Danby. The original text was written in 1991, but was updated by Professor Sir John Rowlinson to include activity over the period 1991-2001.