Alexander Fleming

The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug, make them resistant.

Penicillin is a wonderful drug, but it is not a panacea.

I have been asked to say something about the discovery of penicillin. It is a story of serendipity, of chance observation, and of the application of scientific method.

It is not the discovery of penicillin that is so remarkable, but the fact that it was not discovered earlier.

The mould was growing as a contaminant on a culture plate of staphylococci. It was a chance observation, but one that led to a revolution in medicine.

I had no idea that I had stumbled on a discovery of such magnitude.

The greatest discovery of all time is that a person can change his future by merely changing his attitude.

The penicillin story is a good example of how a simple observation can lead to a profound discovery.

It is a striking fact that the most potent antibacterial agent yet discovered should be a product of a mould.

The development of penicillin has been a triumph of collaboration.

I have often been asked if I foresaw the immense impact of penicillin. My answer is no, not at first.

The bacteriologist must be something of an artist, for he must be able to recognize the subtle differences in the growth of bacteria.

It is not enough to discover; one must also develop and apply.

The discovery of penicillin was a happy accident, but it was also the result of years of patient observation and experimentation.

The world is full of wonders, if only we have the eyes to see them.

The more we learn, the more we realize how much we don't know.

Science is a continuous process of questioning and discovery.

The greatest reward for a scientist is the joy of discovery.

The power of observation is the key to scientific progress.

Never underestimate the power of a simple experiment.