My husband and I were so closely united by our affection and our common work that we passed nearly all of our time together.

I have frequently been questioned, especially by women, of how I could reconcile family life with a scientific career. Well, it has not been easy.

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."

We must not forget that when radium was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity.

When one studies strongly radioactive substances special precautions must be taken. Dust, the air of the room, and one's clothes, all become radioactive.

The sensitive plate, the gas which is ionised, the fluorescent screen, are in reality receivers, into another kind of energy, chemical energy, ionic energy... luminous energy.

Humanity needs practical men, who get the most out of their work, and, without forgetting the general good, safeguard their own interests. But humanity also needs dreamers, for whom the disinterested development of an enterprise is so captivating that it becomes impossible for them to devote their care to their own material profit.