Laboratory notebook entitled "Biological Experiments on Cephalosporin N" Largely a comparison of blood levels in mice and blood levels and excretion in rats, after administration of penicillin G and cephalosporin N. Includes note of experiment by E P Abraham and H W Florey, June 1951, on excretion in urine of mice, and results of work by Heatley and N Smith, on examination for synergistic or antagonistic effects and acquisition of resistance. Work incorporated in 'A comparison of the biological properties of cephalosporin N and penicillin G' by Heatley and Florey in British Journal of Pharmacology and Chemotherapy 1953 vol 8 pp 252-258. September 1952 - April 1953