"I have been so lucky in life, that I have had nothing to do but to collect the fruits of the labours of others."

"The most important thing for a man of science is to have a clear head and a good heart."

"The progress of science is like the ascent of a mountain, where every step brings new horizons into view."

"The desire to do good is the most powerful motive of all."

"It is impossible for me to write anything without feeling myself inspired by a sort of scientific enthusiasm."