"... In the case of ordinary differential equations, the arbitrary elements being numerical parameters, we have to det…"

"In the case of partial differential equations employed in connection with physical problems, their use must be given …"

"Just after the discovery of infinitesmal calculus, physicists began by needing only very simple methods of integratio…"

"We are going to speak of the role of analysis situs in our modern mathematics. This theory is also called the geometr…"

"... Let a perturbation be produced anywhere, like sound; it is not immediately perceived at every other point. There …"

"... Professor Hadamard concludes that the general pattern of invention, or, as it might also be put, of original work…"

"All those who were acquainted with Hadamard know that until the end of his very long life, he retained an extraordina…"

"Although Champollion was an avowed revolutionary and an enthusiastic Bonapartist, one of his earliest discoveries dis…"

"When one's existence which has seemed quite secure suddenly melts away. . . when every security fails and every suppo…"

"I am fully conscious of the fact that my late husband and I did nothing special; we simply tried to remain human in t…"