Caption:

A photograph of a laboratory technician testing the purity of pencillin, taken by James Jarche [1891-1965] for Illustrated magazine in 1943. The technician is testing manufactured penicillin solutions in a laboratory at St Mary's Hospital, Paddington, London. Different dilutions are used to test the strength of the penicillin. A drop of staphylococus culture is put in the penicillin solution. The test tubes are then incubated and the growth, if any, of the bacteria noted. Penicillin is an antibiotic, a chemical effective at very low concentrations which can kill or stop the growth of a disease-causing microbe. Penicillin is produced naturally in moulds of the genus Penicillium, from where the drug gets its name. In 1934, Odhams, publishers of the Daily Herald, launched the magazine Weekly Illustrated. Based on European ideas of photoreportage it was the first British picture magazine. In 1939 the magazine changed its name to Illustrated. It continued to be published until 1958.