Letter from Howard Walter Florey to H N Green, Sheffield Penicillin unlikely to be of use (in B coli pyelitis) could isolate organism and test penicillin susceptibility - if slightly susceptible, worth a try because of high penicillin concentration in urine - Green should contact Prof Christie for supplies. On verso of a letter from H N Green to Florey, 1 May 1944: Is penicillin of use in B Coli Pyelitis - his wife is having recurrent attacks. 2 May 1944