is the fruit of a long tradition, which started with experiments on electron lenses by F. Holweck in Paris and J.J. Trillat in Besanqon. In a recent discussion with A. Guinier and J.J. Trillat, who unfortunate1,y died a few months ago, he (Trillat) confirmed that the experiments he developed with his student, R. Fritz, in '33 concerned electron diffraction only. A few years later, studies on electron microscopy itself emerged in France. They were done independently through two different approaches, those of the groups of G. Dupouy on the one hand and P. Grivet on the other.
The two approaches concerned studies on electron optics and the construction of electron microscopes. G. Dupouy was the first to develop a magnetic microscope, and he obtained the first images in '42. On the other hand, P. Grivet chose another approach since he used electrostatic lenses. The design of this electrostatic microscope was completed in '42 after previous studies. Then it was commercialized in '46 by the Compagnie Frangaise de TSF (CSF).
After the end of World War 11, L. de Broglie organized a series of small meetings on electron optics. The participants were C. Magnan, A. Lallemand, E. Faure-Fremiet, P. Chanson, A. Ertaud, P. Grivet, G. Dupouy, and L. Leaute. Thus physicists and biologists were involved in a reflection on their common interest to electron microscopy as it is done, now, in the Societe Franqaise de Microscopie Electronique. The contributions were published in '46, and micrographs from both microscopes were published in the proceedings. R. Castaing, whose supervisor was A. Guinier, developed during these years his famous microprobe, which was obtained by modifying the existing CSF electrostatic microscope. The first results were presented at the Delft congress in '49 and at the International Congress