Mathematical Treasure: Works of Paul du Bois-Reymond

Paul du Bois-Reymond (1831-1889) was a German mathematician who made several important contributions to real analysis; for example, he established the fact that a trigonometric series that converges to a continuous function at every point is the Fourier series of that function. His treatise Untersuchungen über die Konvergenz und Divergenz der Fourierschen Darstellungsformeln (1876) examined series approximation of functions. The paper was republished in 1912 in the work Abhandlung über die Darstellung der Funktionen durch trigonometrische Reihen:

His work on the general theory of functions, Die allgemeine Functionentheorie, was published in 1882.  The title page below comes from a French translation published in 1887.

The full works, from the University of Toronto, can be viewed in the Internet Archive here and here. Another copy of Théorie génèrale des fonctions is available via Gallica.

Index to Mathematical Treasures