On hearing the news [of being awarded a Nobel Prize], a friend who knows me only too well, sent me this laconic message: 'Blood, toil, sweat and tears always were a good mixture'.

What is known for certain is dull.

I rarely plan my research; it plans me.

For Christmas, 1939, a girl friend gave me a book token which I used to buy Linus Pauling's recently published Nature of the Chemical Bond. His book transformed the chemical flatland of my earlier textbooks into a world of three-dimensional structures.

Could the search for ultimate truth really have revealed so hideous and visceral looking an object?

I saw Linus Pauling as a brilliant lecturer and a man with a fantastic memory, and a great, great showman. I think he was the century's greatest chemist. No doubt about it.

A discovery is like falling in love and reaching the top of a mountain after a hard climb all in one, an ecstasy not induced by drugs but by the revelation of a face of nature that no one has seen before and that often turns out to be more subtle and wonderful than anyone had imagined.