Letter from Howard Walter Florey to A H Campbell, Glaxo Laboratories Limited, Sefton Park, Stoke Poges Thanks for interesting letter about clinical trial of cephalosporin C - will contact Dr Dudgeon if he can - is very busy at present - thanks Campbell for saying he will keep him, Florey, informed about progress of clinical trials - wonders if injection is painful - is told that Celbenin is very painful because of large amount injected. 27 March 1961