Encyclopaedia Britannica, 11th Edition,"Conduction, Electric", volume 6, Slice 8

''Conduction, Electric'' from the ''Encyclopaedia Britannica, 11th Edition'' is a scientific publication likely written in the late 19th century. This article dives into the properties and classifications of electric conductivity and resistivity in various materials, structured around the fundamental principles of electricity. The topic revolves around how substances behave in the presence of an electric field, providing a comprehensive overview of the types of conductors and their applications. The opening portion details the foundational concepts of electric conductivity, defining it as the ability of a substance to reach the same electric potential across its entirety in the absence of an electric force. It categorizes materials into five arbitrary classes based on their conductivity: metallic conductors, non-metallic conductors, dielectric conductors, electrolytic conductors, and gaseous conductors. The text further elaborates on specific examples, such as the varying conductivity of different forms of carbon, and sets the stage for more detailed discussions on the measurable properties of metals, liquids, and gases, which will be explored in subsequent sections.