Where observation is concerned, chance favors only the prepared mind.

Every chemical substance, whether natural or artificial, falls into one of two major categories, according to the spatial characteristic of its form. The distinction is between those substances that have a plane of symmetry and those that do not. The former belong to the mineral, the latter to the living world.

There are no such things as applied sciences, only applications of science.

In matters of observation chance favors only the prepared mind. (not literal translation) - Dan's les champs de observation le hasard ne favorise que les esprits prepares.

Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world. Science is the highest personification of the nation because that nation will remain the first which carries the furthest the works of thought and intelligence.

To bring one's self to believe in a truth that has just dawned upon one is the first step towards progress; to persuade others is the second.

Since the most ancient times, all men, and particularly those who endeavored in the practice of medicine, have brought closer together two natural phenomena of capital importance: illness or fever and fermentation.