Chance favors those who are prepared.

When you believe you have found an important scientific fact, and are feverishly curious to publish it, constrain yourself for days, weeks, years sometimes, fight yourself, try and ruin your own experiments, and only proclaim your discovery after having exhausted all contrary hypotheses. But when, after so many efforts you have at last arrived at a certainty, your joy is one of the greatest which can be felt by a human soul.

What did you do today to receive your instruction?

The grandeur of the acts of men are measured by the inspiration from which they spring.

Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment.

There is a time in every man's life when he looks to his God, when he looks at his life, when he wonders how he will be remembered.

Whatever your career may be, do not let yourselves become tainted by a deprecating and barren scepticism.