When was penicillin discovered?

 Penicillin - was discovered in 1929 by Sir Alexander Fleming, then a professor and lecturer at the Royal College of Surgeons in London. He wanted to find a subtance which would kill bacteria but would not also poison the tissues of the patient' body.

 Fleming discovered peni

cillin by accident while he was reseaching into influenza. He was examining a staphylococcus a kind of germ, when he noticed that it had created a bacteria free circle of mould around itself. When he experimented further, he discovered that this liquid mould which he named penicillin prevented further growth of the staphylococcus germ even when diluted and made 80 times weaker. Also, penicillin had no poisonous effect on the human cells.

 Sir Alexander Fleming published his results in the Journal of Experimental Pathology in 1929.

 For some time it was thought that there was only one penicillin but later it was discovered that the mould could produce four penicillins. They were distinguished by the letters F, G, X and K. The best known is penicillin G, which came into widespread use after the Second World War.