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Does God perform miracles today? The story of Penicillin

October 2004 | by Prof. John Rendle-Short

This is part 1 of a 2 part series

Part 2 is here

I read recently a discussion between two well-known Evangelical ministers. One asked, ‘Is God still performing miracles today?’ The other answered, ‘God can certainly perform miracles today – in fact he can perform miracles at any time. But is he performing miracles at this present time? If he is, they’re rare. I personally haven’t seen any’.

Taken out of context this seems a sweeping statement, but the article had majored on miracles and divine healing, in the dramatic ‘Charismatic’ sense of the word. As a retired medical doctor, I would have to say I almost agree.

In all my medical career I can remember only one occasion when, in a children’s ward, a group of Christians asked if they might hold a small service round a child for whom no treatment had succeeded.

All the staff agreed he was on the point of death. But the day after the service he was greatly improved and was discharged a few days later. That was about 50 years ago and I’ve never seen anything like it since. But that is not the sort of miracle I want to consider here.

The discovery of penicillin


If someone asked you who discovered penicillin, very likely you would reply, ‘Alexander Fleming’ (later Sir Alexander Fleming). You might add that in 1928, a blob of mouldy mucus blew in through the window of his laboratory in Paddington, London. It happened to land on a Petrie dish contained a culture of pathologic Staphylococcus bacteria (staphs).

Fleming had collected these bacteria from a patient and planted them out on the dish some days before going on holiday to Scotland. Having no further use for the specimen, he left the dish with a pile of others in an enamel tray containing the antiseptic, Lysol.

This should have killed all the organisms and made the plates safe for further use. But it so happened that the dish containing the staphs was not fully submerged in the Lysol and so was not properly sterilised.

Lost interest


When Fleming returned to work in September, he examined the pile of Petrie dishes and discarded six or so. Then he noticed that one was different from the rest. It had a blob of mould on it.

Furthermore, while the staphs had grown profusely in the usual way, there was a neat hollow surrounding the mould in which there was no growth. Fleming had never seen anything like this before.

It looked as if something had come out of the mould and killed the staphs around it. He named the substance from the mould penicillin. He showed it to other workers in the laboratory, but no one had ever seen anything like it, nor were they particularly interested. And after a while Fleming lost interest too.

This in brief is the usual story of the origin of the ‘wonder-drug’ penicillin. Professor R. G. Macfarlane

1(to whose books I am indebted for most of the information in this article) lists the chain of events.


He describes them variously as ‘an apparently endless series of strange co-incidents’; ‘pure chance’; ‘a sequence against which the odds must be incalculably large’ — he even used the term ‘miraculous’. Was he right?

The mould — how did it get there?


The commonly held belief is that the mould entered the laboratory through an open window overlooking Praed Street. But this window was never opened. The road outside was busy and noisy — a source of dust and petrol fumes. In fact, it was not possible to undo the catch of the window without scrambling on a cluttered laboratory bench.

However, moulds were being researched in a laboratory on the floor below. So if both laboratory doors happened to be left open together sometime during the holiday period, it is possible that the mould could have been blown up the stairway to the upper floor, through the (open) door of Fleming’s laboratory and on to Fleming’s Petrie dish.

Neither design nor accident


Subsequent experiments have shown that penicillin only acts on organisms (such as staphs), during their earliest stages of growth. So presumablythe penicillin must have been present before the staphs had formed colonies.

Macfarlane writes, ‘In other words the mould colony must have been well grown by the time the first staphs appeared’. But how could this be — Fleming would never have inoculated with bacteria a plate which already showed a growth of mould.

Macfarlane quotes Dr Ronald Hare

2who argues that ‘Fleming would not have incubated that plate, by design or by accident’. The plate had simply been left on the bench for several weeks while Fleming was in Scotland.


Hare also discovered that ‘during the first few days of August 1928 the weather was unusually cold with temperature not exceeding 60ºF. This is the ideal temperature for penicillin to flourish, but not for staphylococci to grow…

‘So during the cold period, the mould grew well and released penicillin. Then about 6 August there was a minor heat wave with temperatures nearing 80ºF. This suited the staphs, which grew and multiplied — all except in the penicillin zone; those around the mould were killed’.

So we have to explain how the mould got there and secondly, if Hare is correct that Fleming did not inoculate the dish, how did the staphs get there?

Publications on penicillin


In May 1929, the year after his discovery, Fleming wrote an article in The British Journal of Experimental Pathology entitled, ‘On the antibacterial action of cultures of a penicillinium with special reference to their use in the isolation of B. influenza’.

Because he was a bacteriologist, Fleming published this paper in a specialist journal — the possible use of penicillin in the treatment of infectious diseases never entered his mind. Apart from this article, Fleming took no further part in the discovery of penicillin, and for ten years the subject lay dormant. He did, however, retain samples of the mould.

Then in 1938, Dr Ernest Chain a research Fellow at Oxford University, was conducting a search of the medical literature on an unrelated topic. After looking at about 200 articles, his eye happened to light on Fleming’s paper — ‘and on reading it, he immediately became interested’.

Of this episode, Macfarlane wrote, ‘Chain’s discovery of Fleming’s long-forgotten paper was a piece of rare good fortune’ (sic).

Chain showed the paper to Professor Howard Florey who, being a physician, immediately appreciated the potential value of penicillin in the treatment of human infections.

Howard Florey

We must now turn our attention to the work done in Oxford. Florey (later Lord Florey) obtained a sample of penicillin from Fleming, and immediately dropped all other projects on which he had been working. He started experiments to discover whether penicillin was toxic to animals.

First he gave it by mouth to mice and rabbits, but found it had no effect — either good or bad. Then, greatly daring, he gave it to humans by mouth, but again with no apparent result.

However, he found that when he administered penicillin to a patient with a bacterial infection directly onto the lesion, or by an intramuscular or intravenous injection, a dramatic cure could result.

World War II


Now we come to another coincidence. Notice the dates 1928 to 1938! The sudden interest in the clinical application of penicillin occurred just before World War II began, introducing a potent weapon in the war against wound infections.

But how could sufficient penicillin in pure form be produced for the treatment of probably thousands of patients in the coming days? The problem was to persuade a pharmaceutical firm to manufacture it in bulk; but during the war chemists were much too busy making routine drugs to waste time on a wild-goose chase.

At last the problem reached the desk of the Prime Minister, Winston Churchill. ‘He immediately wrote in the margin of the memorandum, “This valuable drug must on no account be wasted. It must be used to the best military advantage”.’ (In fact the ‘advantage’ Churchill had in mind was curing gonorrhoea — a scourge which was sweeping the armed forces!).

But British pharmaceutical firms were too busy to help, so the problem of making penicillin in commercial quantity was passed to the United States.

A rare mould


A few years later, when great interest was being taken in penicillin, efforts were made to discover other moulds which would have similar effects. Workers searched the world. Dr Rapier of Peoria Laboratories USA tested thousands of possible samples, but with no positive results.

But he had a helper, Miss Mary Hunt, who collected specimens for him. One day in 1943 (half way through the war) ‘she noticed a piece of rotting cantaloupe melon in a ditch’.

She took it to Rapier for him to examine. He found the mould yielded far more penicillin than Fleming’s famous specimen! A rarity indeed.

So in dramatic fashion this series of ‘strange coincidences’ culminated just in time to allow the production of some penicillin for the D-Day invasion of France, and ushered in what is now known as the ‘antibiotic era’.