His mother Lucie was the daughter of J.C. Jamin, professor of physics at the Sorbonne.

[1][2] He also published a textbook on relativity In 1903 some of his research came into question when he collaborated with surgeon André Broca to examine the radiation (N-Rays) supposedly emanating from living bodies (as claimed originally by René Blondlot) which was claimed to reduce upon the administration of anaesthetics.

[3] In 1909, he became the fourth in his family to occupy the physics chair at the Muséum National d'Histoire Naturelle, following in the footsteps of his father, his grandfather and his great-grandfather.

He examined these using spectroscopy and found that some absorption bands disappeared and this led to a collaboration with Heike Kamerlingh Onnes at Leiden.

Here he examined materials at low-temperatures and described the spectra and looked at magnetic properties.