H.55-H.66: Cornelis, G. Cornelis came from Université Catholique de Louvain, Belgium, to work in Abraham's Laboratory for a few months in 1974. Correspondence and papers regarding visit, research and publications. 1973-1978.

H.67: Crawford, K. Crawford was a Departmental Demonstrator in the Oxford Department, commencing 1 December 1954. Includes the report 'The enzymes inactivating Cephalosporins P and N and Penicillin'. 1958-1959.

H.68-H.73: Crout, D.H.G. Crout was based at the Department of Chemistry, Exeter University. Correspondence and papers regarding research and publications. 1979-1984.