I was taught that the way of progress was neither swift nor easy.

Life is not easy for any of us. But what of that? We must have perseverance and above all confidence in ourselves.

Life is not easy for any of us. But what of that? We must have perseverance and above all confidence in ourselves. We must believe that we are gifted for something, and that this thing, at whatever cost, must be attained.

Pierre Curie voluntarily exposed his arm to the action of radium for several hours. This resulted in damage resembling a burn that developed progressively and required several months to heal. Henri Becquerel had by accident a similar burn as a result of carrying in his vest pocket a glass tube containing radium salt. He came to tell us of this evil effect of radium, exclaiming in a manner at once delighted and annoyed: "I love it, but I owe it a grudge."

I never see what has been done; I only see what remains to be done.

First principle: never to let one's self be beaten down by persons or by events.

All my life through, the new sights of Nature made me rejoice like a child.