When penicillin was invented it was hailed as a "wonder drug".
Before its arrival, pneumonia and post-operative infections killed one in three of those who got them - babies and the elderly were particularly vulnerable.
Within a decade that figure had dropped to just a few per cent.
The Science Museum examines the history of the drug in its new exhibition - Penicillin: A story of Triumph and Tragedy.
Photo credit: Premature baby ward - National Media Museum