The early development of electron lenses and electron microscopy.
D003584:Cytological Techniques; D004583:Electrons; D005858:Germany; D049673:History, 20th Century; D008280:Magnetics; D008854:Microscopy, Electron / Q000266:history* / Q000295:instrumentation / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000295:instrumentation