This paper examines the vital role played by electron microscopy toward the modern definition of viruses, as formulated in the late 1950s. Before the 1930s viruses could neither be visualized by available technologies nor grown in artificial media. As such they were usually identified by their ability to cause diseases in their hosts and defined in such negative terms as “ultramicroscopic” or invisible infectious agents that could not be cultivated outside living cells. The invention of the electron microscope, with magnification and resolution powers several orders of magnitude better than that of optical instruments, opened up possibilities for biological applications. The hitherto invisible viruses lent themselves especially well to investigation with this new instrument. We first offer a historical consideration of the development of the instrument and, more significantly, advances in techniques for preparing and observing specimens that turned the electron microscope into a routine biological tool. We then describe the ways in which the electron microscopic images, or micrographs, functioned as forms of new knowledge about viruses and resulted in a paradigm shift in the very definition of these entities. Micrographs were not mere illustrations since they did the work for the electron microscopists. Drawing extensively on primary publications, we adduce the role of the new instrument in understanding the so-called eclipse phase in virus multiplication and the unexpected spinoffs of data from electron microscopy in naming and classifying viruses. Thus, we show that electron microscopy functioned not only to provide evidence, but also arguments in facilitating a reordering of the world that it brought into the visual realm.

中文翻译：

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眼见如何变为知晓：电子显微镜在塑造现代病毒定义中的作用

本文探讨了电子显微镜对 1950 年代后期制定的现代病毒定义所发挥的重要作用。在 1930 年代之前，病毒既无法通过现有技术可视化，也无法在人工介质中生长。因此，它们通常通过在宿主中引起疾病​​的能力来识别，并用诸如“超微观”或无法在活细胞外培养的不可见传染原这样的负面术语来定义。电子显微镜的发明，其放大倍率和分辨率比光学仪器好几个数量级，为生物学应用开辟了可能性。迄今为止看不见的病毒特别适合用这种新仪器进行调查。我们首先回顾了仪器发展的历史，更重要的是，准备和观察标本的技术进步将电子显微镜变成了常规的生物学工具。然后，我们描述了电子显微图像或显微照片作为有关病毒的新知识形式发挥作用的方式，并导致了这些实体定义的范式转变。显微照片不仅仅是插图，因为它们为电子显微镜师工作。我们广泛借鉴主要出版物，列举了新仪器在理解病毒增殖中所谓的日食阶段的作用，以及电子显微镜数据在病毒命名和分类方面的意外衍生。因此，